diff --git a/.github/workflows/github-actions.yml b/.github/workflows/github-actions.yml
index 40969ecd8..b291ab59c 100644
--- a/.github/workflows/github-actions.yml
+++ b/.github/workflows/github-actions.yml
@@ -14,13 +14,11 @@ on:
     types: [opened, synchronize, reopened, closed]
 jobs:
   build_and_test:
-    if: ${{ github.event_name == 'pull_request' && github.event.action == 'opened' }}
+    if: ${{ github.event_name == 'pull_request' && (github.event.action == 'opened' || github.event.action == 'edited') }}
     runs-on: macos-latest
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
       - uses: actions/checkout@v2
-        with:
-          ref: ${{ github.event.pull_request.head.sha }}
       # Setup node environment for testing
       - uses: actions/setup-node@v2
         with:
@@ -30,9 +28,22 @@ jobs:
         run: yarn install
       - name: run unittest
         run: yarn run test_unit
-      - name: run integration test
-        if: github.event.pull_request.base.ref == 'master'   # integration test only run when master merging
-        run: yarn run test_integration
+      # integration test only run when master merging
+      - name: run blockchain integration test
+        if: github.event.action == 'opened' && github.event.pull_request.base.ref == 'master'
+        run: yarn run test_integration_blockchain
+      - name: run consensus integration test
+        if: github.event.action == 'opened' && github.event.pull_request.base.ref == 'master'
+        run: yarn run test_integration_consensus
+      - name: run dapp integration test
+        if: github.event.action == 'opened' && github.event.pull_request.base.ref == 'master'
+        run: yarn run test_integration_dapp
+      - name: run node integration test
+        if: github.event.action == 'opened' && github.event.pull_request.base.ref == 'master'
+        run: yarn run test_integration_node
+      - name: run sharding integration test
+        if: github.event.action == 'opened' && github.event.pull_request.base.ref == 'master'
+        run: yarn run test_integration_sharding
   check_protocol_version:
     if: ${{ github.event_name == 'push' }}
     runs-on: macos-latest
diff --git a/README.md b/README.md
index fd2e4b1ea..4662fc673 100644
--- a/README.md
+++ b/README.md
@@ -34,13 +34,13 @@ You can override default port numbering system by setting `PORT` and `P2P_PORT`
 ```
 gcloud init
 # For one-off deploy
-sh deploy_blockchain_gcp.sh {dev|spring|summer} <YOUR_GCP_USER_NAME> <NUMBER_OF_SHARDS> [--setup]
+bash deploy_blockchain_gcp.sh {dev|spring|summer} <YOUR_GCP_USER_NAME> <NUMBER_OF_SHARDS> [--setup]
 # For incremental deploy
-sh deploy_blockchain_incremental_gcp.sh {dev|staging|spring|summer} <YOUR_GCP_USER_NAME> <NUMBER_OF_SHARDS> [--setup]
+bash deploy_blockchain_incremental_gcp.sh {dev|staging|spring|summer} <YOUR_GCP_USER_NAME> <NUMBER_OF_SHARDS> [--setup]
 ```
 - Set up Ubuntu machine (if it's on a new VM)
 ```
-sh setup_blockchain_ubuntu.sh
+bash setup_blockchain_ubuntu.sh
 ```
 - Copy files to a sharable folder & install yarn packages
 ```
@@ -49,7 +49,7 @@ source setup_tracker_gcp.sh
 - Start tracker server job
 ```
 cd ain-blockchain/
-sh start_tracker_genesis_gcp.sh
+bash start_tracker_genesis_gcp.sh
 ```
 
 <!--
@@ -97,9 +97,9 @@ yarn install
 ```
 - Run blockchain nodes
 ```
-MIN_NUM_VALIDATORS=3 ACCOUNT_INDEX=0 DEBUG=false STAKE=250 CONSOLE_LOG=true ENABLE_DEV_SET_CLIENT_API=true ENABLE_GAS_FEE_WORKAROUND=true node client/index.js
-MIN_NUM_VALIDATORS=3 ACCOUNT_INDEX=1 DEBUG=false STAKE=250 CONSOLE_LOG=true ENABLE_DEV_SET_CLIENT_API=true ENABLE_GAS_FEE_WORKAROUND=true node client/index.js 
-MIN_NUM_VALIDATORS=3 ACCOUNT_INDEX=2 DEBUG=false STAKE=250 CONSOLE_LOG=true ENABLE_DEV_SET_CLIENT_API=true ENABLE_GAS_FEE_WORKAROUND=true node client/index.js
+MIN_NUM_VALIDATORS=3 ACCOUNT_INDEX=0 DEBUG=false STAKE=100000 CONSOLE_LOG=true ENABLE_DEV_SET_CLIENT_API=true ENABLE_GAS_FEE_WORKAROUND=true node client/index.js
+MIN_NUM_VALIDATORS=3 ACCOUNT_INDEX=1 DEBUG=false STAKE=100000 CONSOLE_LOG=true ENABLE_DEV_SET_CLIENT_API=true ENABLE_GAS_FEE_WORKAROUND=true node client/index.js 
+MIN_NUM_VALIDATORS=3 ACCOUNT_INDEX=2 DEBUG=false STAKE=100000 CONSOLE_LOG=true ENABLE_DEV_SET_CLIENT_API=true ENABLE_GAS_FEE_WORKAROUND=true node client/index.js
 ```
 You can override default port numbering system by setting `PORT` and `P2P_PORT` environment variables.
 Before starting node jobs, remove existing blockchain files and logs if necessary:
@@ -112,7 +112,7 @@ The default minimum size of the validator whitelist is 3. Change MIN_NUM_VALIDAT
 the genesis-configs/base/genesis.json to change this value. You may also need to modify the GENESIS_WHITELIST and GENESIS_VALIDATORS accordingly.
 The genesis configs directory used is `genesis-configs/base` by default and it can be altered using `GENESIS_CONFIGS_DIR` env variable. For example, afan shard cluster can use the following command line:
 ```
-GENESIS_CONFIGS_DIR=genesis-configs/afan-shard MIN_NUM_VALIDATORS=1 ACCOUNT_INDEX=0 DEBUG=false STAKE=250 CONSOLE_LOG=true ENABLE_DEV_SET_CLIENT_API=true ENABLE_GAS_FEE_WORKAROUND=true node client/index.js
+GENESIS_CONFIGS_DIR=genesis-configs/afan-shard MIN_NUM_VALIDATORS=1 ACCOUNT_INDEX=0 DEBUG=false STAKE=100000 CONSOLE_LOG=true ENABLE_DEV_SET_CLIENT_API=true ENABLE_GAS_FEE_WORKAROUND=true node client/index.js
 ```
 
 #### On Google Cloud Platform (GCP)
@@ -122,13 +122,13 @@ GENESIS_CONFIGS_DIR=genesis-configs/afan-shard MIN_NUM_VALIDATORS=1 ACCOUNT_INDE
 ```
 gcloud init
 # For one-off deploy
-sh deploy_blockchain_gcp.sh {dev|spring|summer} <YOUR_GCP_USER_NAME> <NUMBER_OF_SHARDS> [--setup]
+bash deploy_blockchain_gcp.sh {dev|spring|summer} <YOUR_GCP_USER_NAME> <NUMBER_OF_SHARDS> [--setup]
 # For incremental deploy
-sh deploy_blockchain_incremental_gcp.sh {dev|staging|spring|summer} <YOUR_GCP_USER_NAME> <NUMBER_OF_SHARDS> [--setup]
+bash deploy_blockchain_incremental_gcp.sh {dev|staging|spring|summer} <YOUR_GCP_USER_NAME> <NUMBER_OF_SHARDS> [--setup]
 ```
 - Set up Ubuntu machine (if it's on a new VM)
 ```
-sh setup_blockchain_ubuntu.sh
+bash setup_blockchain_ubuntu.sh
 ```
 - Copy files to a sharable folder & install yarn packages
 ```
@@ -136,7 +136,7 @@ source setup_node_gcp.sh
 ```
 - Start Node server job (set shard index to 0 if you're running a root chain node)
 ```
-sh start_node_genesis_gcp.sh {dev|spring|summer} <SHARD_INDEX> <SERVER_INDEX>
+bash start_node_genesis_gcp.sh {dev|spring|summer} <SHARD_INDEX> <SERVER_INDEX>
 ```
 
 <!--
@@ -303,11 +303,11 @@ POST http://<ip_address>:8080/batch with json_body {"tx_list": [{"operation": {"
 
 Four Node server with a Tracker server can be started all at once using `start_servers.sh` like:
 ```
-sh start_servers.sh
+bash start_servers.sh
 ```
 and can be stopped all at once using `stop_servers.sh` like:
 ```
-sh stop_servers.sh
+bash stop_servers.sh
 ```
 
 ## Versions
diff --git a/blockchain/block.js b/blockchain/block.js
index 7515dd7f3..5a9f534fd 100644
--- a/blockchain/block.js
+++ b/blockchain/block.js
@@ -22,13 +22,15 @@ const {
 const PathUtil = require('../common/path-util');
 
 class Block {
-  constructor(lastHash, lastVotes, transactions, number, epoch, timestamp,
+  constructor(lastHash, lastVotes, evidence, transactions, number, epoch, timestamp,
       stateProofHash, proposer, validators, gasAmountTotal, gasCostTotal) {
     this.last_votes = lastVotes;
+    this.evidence = evidence;
     this.transactions = Block.sanitizeTransactions(transactions);
     // Block's header
     this.last_hash = lastHash;
     this.last_votes_hash = CommonUtil.hashString(stringify(lastVotes));
+    this.evidence_hash = CommonUtil.hashString(stringify(this.evidence));
     this.transactions_hash = CommonUtil.hashString(stringify(this.transactions));
     this.number = number;
     this.epoch = epoch;
@@ -48,6 +50,7 @@ class Block {
       last_hash: this.last_hash,
       last_votes_hash: this.last_votes_hash,
       transactions_hash: this.transactions_hash,
+      evidence_hash: this.evidence_hash,
       number: this.number,
       epoch: this.epoch,
       timestamp: this.timestamp,
@@ -62,6 +65,7 @@ class Block {
   get body() {
     return {
       last_votes: this.last_votes,
+      evidence: this.evidence,
       transactions: this.transactions,
     };
   }
@@ -88,16 +92,17 @@ class Block {
     return sizeof({...block.header, ...block.body});
   }
 
-  static create(lastHash, lastVotes, transactions, number, epoch,
-      stateProofHash, proposer, validators, gasAmountTotal, gasCostTotal) {
-    return new Block(lastHash, lastVotes, transactions, number, epoch, Date.now(),
-        stateProofHash, proposer, validators, gasAmountTotal, gasCostTotal);
+  static create(lastHash, lastVotes, evidence, transactions, number, epoch,
+      stateProofHash, proposer, validators, gasAmountTotal, gasCostTotal, timestamp) {
+    return new Block(lastHash, lastVotes, evidence, transactions, number, epoch,
+        timestamp ? timestamp : Date.now(), stateProofHash, proposer, validators, gasAmountTotal,
+        gasCostTotal);
   }
 
   static parse(blockInfo) {
     if (!Block.hasRequiredFields(blockInfo)) return null;
     if (blockInfo instanceof Block) return blockInfo;
-    return new Block(blockInfo.last_hash, blockInfo.last_votes,
+    return new Block(blockInfo.last_hash, blockInfo.last_votes, blockInfo.evidence,
         blockInfo.transactions, blockInfo.number, blockInfo.epoch, blockInfo.timestamp,
         blockInfo.state_proof_hash, blockInfo.proposer, blockInfo.validators,
         blockInfo.gas_amount_total, blockInfo.gas_cost_total);
@@ -105,8 +110,8 @@ class Block {
 
   static hasRequiredFields(block) {
     return (block && block.last_hash !== undefined && block.last_votes !== undefined &&
-        block.transactions !== undefined && block.number !== undefined &&
-        block.epoch !== undefined && block.timestamp !== undefined &&
+        block.evidence !== undefined && block.transactions !== undefined &&
+        block.number !== undefined && block.epoch !== undefined && block.timestamp !== undefined &&
         block.state_proof_hash !== undefined && block.proposer !== undefined &&
         block.validators !== undefined && block.gas_amount_total !== undefined &&
         block.gas_cost_total !== undefined);
@@ -129,6 +134,11 @@ class Block {
           `[${LOG_HEADER}] Last votes or last_votes_hash is incorrect for block ${block.hash}`);
       return false;
     }
+    if (block.evidence_hash !== CommonUtil.hashString(stringify(block.evidence))) {
+      logger.error(
+        `[${LOG_HEADER}] Evidence or evidence_hash is incorrect for block ${block.hash}`);
+      return false;
+    }
     return true;
   }
 
@@ -138,8 +148,8 @@ class Block {
       if (!CommonUtil.isCksumAddr(address)) {
         return false;
       }
-      if (!CommonUtil.isDict(info) || !CommonUtil.isNumber(info[PredefinedDbPaths.STAKE]) ||
-          !CommonUtil.isBool(info[PredefinedDbPaths.PROPOSAL_RIGHT])) {
+      if (!CommonUtil.isDict(info) || !CommonUtil.isNumber(info[PredefinedDbPaths.CONSENSUS_STAKE]) ||
+          !CommonUtil.isBool(info[PredefinedDbPaths.CONSENSUS_PROPOSAL_RIGHT])) {
         return false;
       }
     }
@@ -292,7 +302,7 @@ class Block {
         operation: {
           type: 'SET_VALUE',
           ref: PathUtil.getStakingStakeRecordValuePath(PredefinedDbPaths.CONSENSUS, address, 0, timestamp),
-          value: info[PredefinedDbPaths.STAKE]
+          value: info[PredefinedDbPaths.CONSENSUS_STAKE]
         }
       };
       txs.push(Transaction.fromTxBody(txBody, privateKey));
@@ -315,13 +325,13 @@ class Block {
     return [firstTx, secondTx, thirdTx, ...stakingTxs];
   }
 
-  static executeGenesisTxsAndGetData(genesisTxs) {
+  static executeGenesisTxsAndGetData(genesisTxs, genesisTime) {
     const tempGenesisDb = new DB(
         new StateNode(StateVersions.EMPTY), StateVersions.EMPTY, null, null, false, -1, null);
     tempGenesisDb.initDbStates();
     const resList = [];
     for (const tx of genesisTxs) {
-      const res = tempGenesisDb.executeTransaction(Transaction.toExecutable(tx), true);
+      const res = tempGenesisDb.executeTransaction(Transaction.toExecutable(tx), true, false, 0, genesisTime);
       if (CommonUtil.isFailedTx(res)) {
         logger.error(`Genesis transaction failed:\n${JSON.stringify(tx, null, 2)}` +
             `\nRESULT: ${JSON.stringify(res)}`)
@@ -345,13 +355,14 @@ class Block {
     const genesisTime = GenesisAccounts[AccountProperties.TIMESTAMP];
     const lastHash = '';
     const lastVotes = [];
+    const evidence = {};
     const transactions = Block.getGenesisBlockTxs(genesisTime);
     const number = 0;
     const epoch = 0;
     const proposer = ownerAddress;
     const validators = GENESIS_VALIDATORS;
-    const { stateProofHash, gasAmountTotal, gasCostTotal } = Block.executeGenesisTxsAndGetData(transactions);
-    return new Block(lastHash, lastVotes, transactions, number, epoch, genesisTime,
+    const { stateProofHash, gasAmountTotal, gasCostTotal } = Block.executeGenesisTxsAndGetData(transactions, genesisTime);
+    return new Block(lastHash, lastVotes, evidence, transactions, number, epoch, genesisTime,
         stateProofHash, proposer, validators, gasAmountTotal, gasCostTotal);
   }
 }
diff --git a/client/index.js b/client/index.js
index ccaa4ce08..b5f59b44e 100755
--- a/client/index.js
+++ b/client/index.js
@@ -15,7 +15,8 @@ const {
   PORT,
   BlockchainNodeStates,
   WriteDbOperations,
-  PredefinedDbPaths,
+  NETWORK_ID,
+  CHAIN_ID
 } = require('../common/constants');
 const { ConsensusStates } = require('../consensus/constants');
 
@@ -80,7 +81,7 @@ app.get('/get_value', (req, res, next) => {
   const result = node.db.getValue(req.query.ref, CommonUtil.toGetOptions(req.query));
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: result !== null ? 0 : 1, result})
+    .send({ code: result !== null ? 0 : 1, result })
     .end();
 });
 
@@ -88,7 +89,7 @@ app.get('/get_function', (req, res, next) => {
   const result = node.db.getFunction(req.query.ref, CommonUtil.toGetOptions(req.query));
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: result !== null ? 0 : 1, result})
+    .send({ code: result !== null ? 0 : 1, result })
     .end();
 });
 
@@ -96,7 +97,7 @@ app.get('/get_rule', (req, res, next) => {
   const result = node.db.getRule(req.query.ref, CommonUtil.toGetOptions(req.query));
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: result !== null ? 0 : 1, result})
+    .send({ code: result !== null ? 0 : 1, result })
     .end();
 });
 
@@ -104,7 +105,7 @@ app.get('/get_owner', (req, res, next) => {
   const result = node.db.getOwner(req.query.ref, CommonUtil.toGetOptions(req.query));
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: result !== null ? 0 : 1, result})
+    .send({ code: result !== null ? 0 : 1, result })
     .end();
 });
 
@@ -115,7 +116,7 @@ app.get('/get_state_proof', (req, res, next) => {
   const result = node.db.getStateProof(req.query.ref);
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: result !== null ? 0 : 1, result})
+    .send({ code: result !== null ? 0 : 1, result })
     .end();
 });
 
@@ -126,18 +127,18 @@ app.get('/get_state_info', (req, res, next) => {
   const result = node.db.getStateInfo(req.query.ref);
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: result !== null ? 0 : 1, result})
+    .send({ code: result !== null ? 0 : 1, result })
     .end();
 });
 
 /**
  * Returns the state usage of the given app.
  */
- app.get('/get_state_usage', (req, res, next) => {
+app.get('/get_state_usage', (req, res, next) => {
   const result = node.getStateUsage(req.query.app_name);
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: result !== null ? 0 : 1, result})
+    .send({ code: result !== null ? 0 : 1, result })
     .end();
 });
 
@@ -145,7 +146,7 @@ app.get('/match_function', (req, res, next) => {
   const result = node.db.matchFunction(req.query.ref, CommonUtil.toMatchOrEvalOptions(req.query));
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: result !== null ? 0 : 1, result})
+    .send({ code: result !== null ? 0 : 1, result })
     .end();
 });
 
@@ -153,7 +154,7 @@ app.get('/match_rule', (req, res, next) => {
   const result = node.db.matchRule(req.query.ref, CommonUtil.toMatchOrEvalOptions(req.query));
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: result !== null ? 0 : 1, result})
+    .send({ code: result !== null ? 0 : 1, result })
     .end();
 });
 
@@ -161,7 +162,7 @@ app.get('/match_owner', (req, res, next) => {
   const result = node.db.matchOwner(req.query.ref, CommonUtil.toMatchOrEvalOptions(req.query));
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: result !== null ? 0 : 1, result})
+    .send({ code: result !== null ? 0 : 1, result })
     .end();
 });
 
@@ -179,7 +180,7 @@ app.post('/eval_rule', (req, res, next) => {
       CommonUtil.toMatchOrEvalOptions(body));
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -196,7 +197,7 @@ app.post('/eval_owner', (req, res, next) => {
       body.ref, body.permission, auth, CommonUtil.toMatchOrEvalOptions(body));
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -204,7 +205,7 @@ app.post('/get', (req, res, next) => {
   const result = node.db.get(req.body.op_list);
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -214,7 +215,7 @@ if (ENABLE_DEV_SET_CLIENT_API) {
         req.body, WriteDbOperations.SET_VALUE));
     res.status(200)
       .set('Content-Type', 'application/json')
-      .send({code: CommonUtil.isFailedTx(result.result) ? 1 : 0, result})
+      .send({ code: CommonUtil.isFailedTx(result.result) ? 1 : 0, result })
       .end();
   });
 
@@ -223,7 +224,7 @@ if (ENABLE_DEV_SET_CLIENT_API) {
         req.body, WriteDbOperations.INC_VALUE));
     res.status(200)
       .set('Content-Type', 'application/json')
-      .send({code: CommonUtil.isFailedTx(result.result) ? 1 : 0, result})
+      .send({ code: CommonUtil.isFailedTx(result.result) ? 1 : 0, result })
       .end();
   });
 
@@ -232,7 +233,7 @@ if (ENABLE_DEV_SET_CLIENT_API) {
         req.body, WriteDbOperations.DEC_VALUE));
     res.status(200)
       .set('Content-Type', 'application/json')
-      .send({code: CommonUtil.isFailedTx(result.result) ? 1 : 0, result})
+      .send({ code: CommonUtil.isFailedTx(result.result) ? 1 : 0, result })
       .end();
   });
 
@@ -241,7 +242,7 @@ if (ENABLE_DEV_SET_CLIENT_API) {
         req.body, WriteDbOperations.SET_FUNCTION));
     res.status(200)
       .set('Content-Type', 'application/json')
-      .send({code: CommonUtil.isFailedTx(result.result) ? 1 : 0, result})
+      .send({ code: CommonUtil.isFailedTx(result.result) ? 1 : 0, result })
       .end();
   });
 
@@ -250,7 +251,7 @@ if (ENABLE_DEV_SET_CLIENT_API) {
         req.body, WriteDbOperations.SET_RULE));
     res.status(200)
       .set('Content-Type', 'application/json')
-      .send({code: CommonUtil.isFailedTx(result.result) ? 1 : 0, result})
+      .send({ code: CommonUtil.isFailedTx(result.result) ? 1 : 0, result })
       .end();
   });
 
@@ -259,7 +260,7 @@ if (ENABLE_DEV_SET_CLIENT_API) {
         req.body, WriteDbOperations.SET_OWNER));
     res.status(200)
       .set('Content-Type', 'application/json')
-      .send({code: CommonUtil.isFailedTx(result.result) ? 1 : 0, result})
+      .send({ code: CommonUtil.isFailedTx(result.result) ? 1 : 0, result })
       .end();
   });
 
@@ -269,7 +270,7 @@ if (ENABLE_DEV_SET_CLIENT_API) {
     const result = createAndExecuteTransaction(createMultiSetTxBody(req.body));
     res.status(200)
       .set('Content-Type', 'application/json')
-      .send({code: CommonUtil.isFailedTx(result.result) ? 1 : 0, result})
+      .send({ code: CommonUtil.isFailedTx(result.result) ? 1 : 0, result })
       .end();
   });
 
@@ -277,16 +278,31 @@ if (ENABLE_DEV_SET_CLIENT_API) {
     const result = createAndExecuteTransaction(createBatchTxBody(req.body));
     res.status(200)
       .set('Content-Type', 'application/json')
-      .send({code: 0, result})
+      .send({ code: 0, result })
       .end();
   });
+
+  app.post('/broadcast_consensus_msg', (req, res) => {
+    p2pClient.broadcastConsensusMessage(req.body);
+    res.status(200)
+      .set('Content-Type', 'application/json')
+      .send({ code: 0, result: true })
+      .end();
+  });
+
+  app.post('/sign_transaction', (req, res) => {
+    res.status(200)
+      .set('Content-Type', 'application/json')
+      .send({ code: 0, result: node.createTransaction(req.body) })
+      .end();
+  })
 }
 
 app.get('/status', (req, res, next) => {
   const result = p2pClient.getStatus();
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -294,7 +310,7 @@ app.get('/node_status', (req, res, next) => {
   const result = p2pServer.getNodeStatus();
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -302,7 +318,7 @@ app.get('/connection_status', (req, res) => {
   const result = p2pClient.getConnectionStatus();
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 })
 
@@ -312,7 +328,7 @@ app.get('/blocks', (req, res, next) => {
   const result = node.bc.getBlockList(blockBegin, blockEnd);
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -320,7 +336,7 @@ app.get('/last_block', (req, res, next) => {
   const result = node.bc.lastBlock();
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -328,7 +344,7 @@ app.get('/last_block_number', (req, res, next) => {
   const result = node.bc.lastBlockNumber();
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -336,7 +352,7 @@ app.get('/tx_pool', (req, res, next) => {
   const result = node.tp.transactions;
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -344,7 +360,7 @@ app.get('/tx_tracker', (req, res, next) => {
   const result = node.tp.transactionTracker;
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -352,7 +368,7 @@ app.get('/committed_nonce_tracker', (req, res, next) => {
   const result = node.tp.committedNonceTracker;
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -360,7 +376,7 @@ app.get('/pending_nonce_tracker', (req, res, next) => {
   const result = node.tp.pendingNonceTracker;
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -368,7 +384,7 @@ app.get('/protocol_versions', (req, res) => {
   const result = p2pClient.server.getProtocolInfo();
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -376,7 +392,7 @@ app.get('/state_versions', (req, res) => {
   const result = p2pServer.getStateVersionStatus();
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -385,7 +401,7 @@ app.get('/dump_final_db_states', (req, res) => {
   const result = node.dumpFinalDbStates(CommonUtil.toGetOptions(req.query));
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -394,7 +410,7 @@ app.get('/tx_pool_size_util', (req, res) => {
   const txPoolSizeUtil = node.getTxPoolSizeUtilization(address);
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result: txPoolSizeUtil})
+    .send({ code: 0, result: txPoolSizeUtil })
     .end();
 });
 
@@ -402,7 +418,7 @@ app.get('/get_transaction', (req, res, next) => {
   const transactionInfo = node.getTransactionByHash(req.query.hash);
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result: transactionInfo})
+    .send({ code: 0, result: transactionInfo })
     .end();
 });
 
@@ -410,7 +426,7 @@ app.get('/get_block_by_hash', (req, res, next) => {
   const block = node.bc.getBlockByHash(req.query.hash);
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result: block})
+    .send({ code: 0, result: block })
     .end();
 });
 
@@ -418,7 +434,7 @@ app.get('/get_block_by_number', (req, res, next) => {
   const block = node.bc.getBlockByNumber(req.query.number);
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result: block})
+    .send({ code: 0, result: block })
     .end();
 });
 
@@ -426,7 +442,7 @@ app.get('/get_address', (req, res, next) => {
   const result = node.account.address;
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -434,7 +450,7 @@ app.get('/get_nonce', (req, res, next) => {
   const result = node.getNonceForAddr(req.query.address, req.query.from === 'pending');
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -442,7 +458,7 @@ app.get('/get_timestamp', (req, res, next) => {
   const result = node.getTimestampForAddr(req.query.address, req.query.from === 'pending');
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -450,7 +466,7 @@ app.get('/get_sharding', (req, res, next) => {
   const result = node.getSharding();
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: result !== null ? 0 : 1, result})
+    .send({ code: result !== null ? 0 : 1, result })
     .end();
 });
 
@@ -458,7 +474,7 @@ app.get('/get_raw_consensus_status', (req, res) => {
   const result = p2pServer.consensus.getRawStatus();
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
     .end();
 });
 
@@ -466,7 +482,21 @@ app.get('/get_consensus_status', (req, res) => {
   const result = p2pServer.consensus.getStatus();
   res.status(200)
     .set('Content-Type', 'application/json')
-    .send({code: 0, result})
+    .send({ code: 0, result })
+    .end();
+});
+
+app.get('/get_network_id', (req, res) => {
+  res.status(200)
+    .set('Content-Type', 'application/json')
+    .send({ code: 0, result: NETWORK_ID })
+    .end();
+});
+
+app.get('/get_chain_id', (req, res) => {
+  res.status(200)
+    .set('Content-Type', 'application/json')
+    .send({ code: 0, result: CHAIN_ID })
     .end();
 });
 
diff --git a/client/protocol_versions.json b/client/protocol_versions.json
index 495988914..976e76a78 100644
--- a/client/protocol_versions.json
+++ b/client/protocol_versions.json
@@ -61,5 +61,8 @@
   },
   "0.9.0": {
     "min": "0.9.0"
+  },
+  "0.9.1": {
+    "min": "0.9.0"
   }
 }
\ No newline at end of file
diff --git a/common/common-util.js b/common/common-util.js
index c6756e879..a2460f5fd 100644
--- a/common/common-util.js
+++ b/common/common-util.js
@@ -4,7 +4,6 @@ const _ = require('lodash');
 const CURRENT_PROTOCOL_VERSION = require('../package.json').version;
 const RuleUtil = require('../db/rule-util');
 const ruleUtil = new RuleUtil();
-const PRIVATE_KEY = process.env.PRIVATE_KEY || null;
 
 class CommonUtil {
   static hashString(stringData) {
@@ -21,12 +20,12 @@ class CommonUtil {
     return '0x' + ainUtil.hashTransaction(txBody).toString('hex');
   }
 
-  static signTransaction(txBody, privateKey) {
+  static signTransaction(txBody, privateKey, chainId) {
     if (!privateKey) {
       return null;
     }
     const keyBuffer = Buffer.from(privateKey, 'hex');
-    const sig = ainUtil.ecSignTransaction(txBody, keyBuffer);
+    const sig = ainUtil.ecSignTransaction(txBody, keyBuffer, chainId);
     const sigBuffer = ainUtil.toBuffer(sig);
     const lenHash = sigBuffer.length - 65;
     const hashedData = sigBuffer.slice(0, lenHash);
@@ -98,6 +97,14 @@ class CommonUtil {
     return ruleUtil.isEmpty(value);
   }
 
+  static isHexString(value) {
+    return ruleUtil.isHexString(value);
+  }
+
+  static isValidHash(value) {
+    return ruleUtil.isValidHash(value);
+  }
+
   static isValAddr(value) {
     return ruleUtil.isValAddr(value);
   }
@@ -118,6 +125,10 @@ class CommonUtil {
     return ruleUtil.isValShardProto(value);
   }
 
+  static isValidatorOffenseType(type) {
+    return ruleUtil.isValidatorOffenseType(type);
+  }
+
   static boolOrFalse(value) {
     return ruleUtil.boolOrFalse(value);
   }
@@ -138,6 +149,31 @@ class CommonUtil {
     return ruleUtil.toNumberOrNaN(value);
   }
 
+  static toString(value) {
+    if (CommonUtil.isBool(value)) {
+      return value.toString();
+    } else if (CommonUtil.isNumber(value)) {
+      return value.toString();
+    } else if (CommonUtil.isString(value)) {
+      return value;
+    } else if (value === undefined) {
+      return '';
+    } else {
+      return JSON.stringify(value);
+    }
+  }
+
+  /**
+   * Converts the given string to a hex string (with lower case).
+   */
+  static toHexString(str) {
+    if (this.isHexString(str)) {
+      return str.toLowerCase();
+    }
+    const hexStr = this.isString(str) ? Buffer.from(str).toString('hex') : '';
+    return '0x' + hexStr;
+  }
+
   static toCksumAddr(addr) {
     return ruleUtil.toCksumAddr(addr);
   }
@@ -157,27 +193,13 @@ class CommonUtil {
   // NOTE(liayoo): billing is in the form <app name>|<billing id>
   static toBillingAccountName(billing) {
     const { PredefinedDbPaths } = require('../common/constants');
-    return `${PredefinedDbPaths.BILLING}|${billing}`;
+    return `${PredefinedDbPaths.GAS_FEE_BILLING}|${billing}`;
   }
 
   static toEscrowAccountName(source, target, escrowKey) {
     return ruleUtil.toEscrowAccountName(source, target, escrowKey);
   }
 
-  static toString(value) {
-    if (CommonUtil.isBool(value)) {
-      return value.toString();
-    } else if (CommonUtil.isNumber(value)) {
-      return value.toString();
-    } else if (CommonUtil.isString(value)) {
-      return value;
-    } else if (value === undefined) {
-      return '';
-    } else {
-      return JSON.stringify(value);
-    }
-  }
-
   static toGetOptions(args) {
     const options = {};
     if (args.is_shallow !== undefined) {
@@ -686,6 +708,11 @@ class CommonUtil {
     });
     return obj;
   }
+
+  static getDayTimestamp(timestamp) {
+    const date = new Date(timestamp);
+    return Date.UTC(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate());
+  }
 }
 
 module.exports = CommonUtil;
diff --git a/common/constants.js b/common/constants.js
index 4094d059d..66c694765 100644
--- a/common/constants.js
+++ b/common/constants.js
@@ -18,7 +18,7 @@ const FeatureFlags = {
   // Enables state version optimization.
   enableStateVersionOpt: true,
   // Enables state tree transfer.
-  enableStateTreeTransfer: true,
+  enableStateTreeTransfer: false,
   // Enables rich logging for functions.
   enableRichFunctionLogging: false,
   // Enables rich logging for transactions.
@@ -28,7 +28,13 @@ const FeatureFlags = {
   // Enables rich logging for tx selection in tx pool.
   enableRichTxSelectionLogging: false,
   // Enables receipt path's prefix layers.
-  enableReceiptPathPrefixLayers: true,
+  enableReceiptPathPrefixLayers: false,  // Some test cases assume this value false.
+  // Enables radix layers.
+  enableRadixTreeLayers: true,  // Some test cases assume this value true.
+  // Enables hex label cache.
+  enableHexLabelCache: false,
+  // Enables array radix child map.
+  enableArrayRadixChildMap: false,
 };
 
 // ** Environment variables **
@@ -39,8 +45,6 @@ const ENABLE_TX_SIG_VERIF_WORKAROUND =
     CommonUtil.convertEnvVarInputToBool(process.env.ENABLE_TX_SIG_VERIF_WORKAROUND);
 const ENABLE_GAS_FEE_WORKAROUND =
     CommonUtil.convertEnvVarInputToBool(process.env.ENABLE_GAS_FEE_WORKAROUND, true);
-const COMCOM_HOST_EXTERNAL_IP = process.env.COMCOM_HOST_EXTERNAL_IP ?
-    process.env.COMCOM_HOST_EXTERNAL_IP : '';
 const ACCOUNT_INDEX = process.env.ACCOUNT_INDEX || null;
 const PORT = process.env.PORT || getPortNumber(8080, 8080);
 const P2P_PORT = process.env.P2P_PORT || getPortNumber(5000, 5000);
@@ -104,7 +108,7 @@ const FREE_BANDWIDTH_BUDGET_PER_BLOCK = bandwidthBudgetPerBlock * FREE_BANDWIDTH
 const SERVICE_STATE_BUDGET = stateTreeBytesLimit * SERVICE_STATE_BUDGET_RATIO;
 const APPS_STATE_BUDGET = stateTreeBytesLimit * APPS_STATE_BUDGET_RATIO;
 const FREE_STATE_BUDGET = stateTreeBytesLimit * FREE_STATE_BUDGET_RATIO;
-const MAX_STATE_TREE_SIZE_PER_BYTE = 0.005;
+const MAX_STATE_TREE_SIZE_PER_BYTE = 0.01;
 const TREE_SIZE_BUDGET = stateTreeBytesLimit * MAX_STATE_TREE_SIZE_PER_BYTE;
 const SERVICE_TREE_SIZE_BUDGET = SERVICE_STATE_BUDGET * MAX_STATE_TREE_SIZE_PER_BYTE;
 const APPS_TREE_SIZE_BUDGET = APPS_STATE_BUDGET * MAX_STATE_TREE_SIZE_PER_BYTE;
@@ -156,30 +160,44 @@ const PredefinedDbPaths = {
   DOT_SHARD: '.shard',
   // Consensus
   CONSENSUS: 'consensus',
-  WHITELIST: 'whitelist',
-  NUMBER: 'number',
-  PROPOSE: 'propose',
-  PROPOSER: 'proposer',
-  VALIDATORS: 'validators',
-  TOTAL_AT_STAKE: 'total_at_stake',
-  VOTE: 'vote',
-  BLOCK_HASH: 'block_hash',
-  STAKE: 'stake',
-  PROPOSAL_RIGHT: 'proposal_right',
+  CONSENSUS_BLOCK_HASH: 'block_hash',
+  CONSENSUS_IS_AGAINST: 'is_against',
+  CONSENSUS_NUMBER: 'number',
+  CONSENSUS_OFFENSE_RECORDS: 'offense_records',
+  CONSENSUS_OFFENSE_TYPE: 'offense_type',
+  CONSENSUS_PROPOSAL_RIGHT: 'proposal_right',
+  CONSENSUS_PROPOSE: 'propose',
+  CONSENSUS_PROPOSER: 'proposer',
+  CONSENSUS_REWARDS: 'rewards',
+  CONSENSUS_REWARDS_UNCLAIMED: 'unclaimed',
+  CONSENSUS_REWARDS_CUMULATIVE: 'cumulative',
+  CONSENSUS_STAKE: 'stake',
+  CONSENSUS_TOTAL_AT_STAKE: 'total_at_stake',
+  CONSENSUS_VALIDATORS: 'validators',
+  CONSENSUS_VOTE: 'vote',
+  CONSENSUS_WHITELIST: 'whitelist',
   // Receipts
   RECEIPTS: 'receipts',
   RECEIPTS_ADDRESS: 'address',
   RECEIPTS_BILLING: 'billing',
   RECEIPTS_BLOCK_NUMBER: 'block_number',
   RECEIPTS_EXEC_RESULT: 'exec_result',
-  RECEIPTS_GAS_COST_TOTAL: 'gas_cost_total',
+  RECEIPTS_EXEC_RESULT_CODE: 'code',
+  RECEIPTS_EXEC_RESULT_ERROR_MESSAGE: 'error_message',
+  RECEIPTS_EXEC_RESULT_GAS_AMOUNT_CHARGED: 'gas_amount_charged',
+  RECEIPTS_EXEC_RESULT_GAS_COST_TOTAL: 'gas_cost_total',
+  RECEIPTS_EXEC_RESULT_RESULT_LIST: 'result_list',
   // Gas fee
   GAS_FEE: 'gas_fee',
-  COLLECT: 'collect',
-  BILLING: 'billing',
   GAS_FEE_AMOUNT: 'amount',
+  GAS_FEE_BILLING: 'billing',
+  GAS_FEE_CLAIM: 'claim',
+  GAS_FEE_COLLECT: 'collect',
+  GAS_FEE_UNCLAIMED: 'unclaimed',
   // Token
   TOKEN: 'token',
+  TOKEN_BRIDGE: 'bridge',
+  TOKEN_BRIDGE_TOKEN_POOL: 'token_pool',
   TOKEN_NAME: 'name',
   TOKEN_SYMBOL: 'symbol',
   TOKEN_TOTAL_SUPPLY: 'total_supply',
@@ -242,6 +260,13 @@ const PredefinedDbPaths = {
   CHECKIN_PAYLOAD: 'payload',
   CHECKIN_PARENT_FINALIZE: 'parent_finalize',
   CHECKOUT: 'checkout',
+  CHECKOUT_HISTORY: 'history',
+  CHECKOUT_HISTORY_REFUND: 'refund',
+  CHECKOUT_REQUESTS: 'requests',
+  CHECKOUT_STATS: 'stats',
+  CHECKOUT_STATS_COMPLETE: 'complete',
+  CHECKOUT_STATS_PENDING: 'pending',
+  CHECKOUT_STATS_TOTAL: 'total',
 };
 
 /**
@@ -253,6 +278,21 @@ const TokenProperties = {
   NAME: 'name',
   SYMBOL: 'symbol',
   TOTAL_SUPPLY: 'total_supply',
+  BRIDGE: 'bridge',
+};
+
+/**
+ * Properties of token bridge configs.
+ *
+ * @enum {string}
+ */
+ const TokenBridgeProperties = {
+  TOKEN_POOL: 'token_pool',
+  MIN_CHECKOUT_PER_REQUEST: 'min_checkout_per_request',
+  MAX_CHECKOUT_PER_REQUEST: 'max_checkout_per_request',
+  MAX_CHECKOUT_PER_DAY: 'max_checkout_per_day',
+  TOKEN_EXCH_RATE: 'token_exchange_rate',
+  TOKEN_EXCH_SCHEME: 'token_exchange_scheme',
 };
 
 /**
@@ -322,7 +362,9 @@ const FunctionTypes = {
  * @enum {string}
  */
 const ProofProperties = {
+  LABEL: '.label',
   PROOF_HASH: '.proof_hash',
+  RADIX_PROOF_HASH: '.radix_ph',
 };
 
 /**
@@ -346,13 +388,17 @@ const StateInfoProperties = {
  */
 const NativeFunctionIds = {
   CLAIM: '_claim',
+  CLAIM_REWARD: '_claimReward',
   CLOSE_CHECKIN: '_closeCheckin',
+  CLOSE_CHECKOUT: '_closeCheckout',
   COLLECT_FEE: '_collectFee',
   CREATE_APP: '_createApp',
   DISTRIBUTE_FEE: '_distributeFee',
   ERASE_VALUE: '_eraseValue',
+  HANDLE_OFFENSES: '_handleOffenses',
   HOLD: '_hold',
   OPEN_CHECKIN: '_openCheckin',
+  OPEN_CHECKOUT: '_openCheckout',
   PAY: '_pay',
   RELEASE: '_release',
   SAVE_LAST_TX: '_saveLastTx',
@@ -445,16 +491,25 @@ const WriteDbOperations = {
 /**
  * Function result code.
  *
- * @enum {string}
+ * @enum {number}
  */
 const FunctionResultCode = {
-  FAILURE: 'FAILURE',  // Normal failure
-  IN_LOCKUP_PERIOD: 'IN_LOCKUP_PERIOD',
-  INSUFFICIENT_BALANCE: 'INSUFFICIENT_BALANCE',
-  INTERNAL_ERROR: 'INTERNAL_ERROR',  // Something went wrong but don't know why
-  INVALID_ACCOUNT_NAME: 'INVALID_ACCOUNT_NAME',
-  INVALID_SERVICE_NAME: 'INVALID_SERVICE_NAME',
-  SUCCESS: 'SUCCESS',
+  SUCCESS: 0,
+  FAILURE: 1,  // Normal failure
+  INTERNAL_ERROR: 2,  // Something went wrong but don't know why
+  // Transfer
+  INSUFFICIENT_BALANCE: 100,
+  // Staking
+  IN_LOCKUP_PERIOD: 200,
+  // Create app
+  INVALID_SERVICE_NAME: 300,
+  // Checkout
+  INVALID_ACCOUNT_NAME: 400,
+  INVALID_CHECKOUT_AMOUNT: 401,
+  INVALID_RECIPIENT: 402,
+  INVALID_TOKEN_BRIDGE_CONFIG: 403,
+  // Claim reward
+  INVALID_AMOUNT: 500,
 };
 
 /**
@@ -508,6 +563,7 @@ const GasFeeConstants = {
 const SERVICE_TYPES = [
   PredefinedDbPaths.ACCOUNTS,
   PredefinedDbPaths.CHECKIN,
+  PredefinedDbPaths.CHECKOUT,
   PredefinedDbPaths.ESCROW,
   PredefinedDbPaths.GAS_FEE,
   PredefinedDbPaths.MANAGE_APP,
@@ -526,7 +582,7 @@ function isServiceType(type) {
  * Service types allowed to create service accounts.
  */
 const SERVICE_ACCOUNT_SERVICE_TYPES = [
-  PredefinedDbPaths.BILLING,
+  PredefinedDbPaths.GAS_FEE_BILLING,
   PredefinedDbPaths.ESCROW,
   PredefinedDbPaths.GAS_FEE,
   PredefinedDbPaths.PAYMENTS,
@@ -583,8 +639,8 @@ function overwriteGenesisParams(overwritingParams, type) {
       const addr = GenesisAccounts[AccountProperties.OTHERS][i][AccountProperties.ADDRESS];
       CommonUtil.setJsObject(whitelist, [addr], true);
       CommonUtil.setJsObject(validators, [addr], {
-          [PredefinedDbPaths.STAKE]: GenesisParams.consensus.MIN_STAKE_PER_VALIDATOR,
-          [PredefinedDbPaths.PROPOSAL_RIGHT]: true
+          [PredefinedDbPaths.CONSENSUS_STAKE]: GenesisParams.consensus.MIN_STAKE_PER_VALIDATOR,
+          [PredefinedDbPaths.CONSENSUS_PROPOSAL_RIGHT]: true
         });
     }
     GenesisParams.consensus.GENESIS_WHITELIST = whitelist;
@@ -602,11 +658,8 @@ function initializeNetworkEnvronments() {
     return GenesisParams.network;
   } else {
     return {
-      // NOTE(minsulee2): Need a discussion that MAX_NUM_VALIDATORS and MAX_INBOUND_LIMIT
-      // should not be related to one another.
       P2P_MESSAGE_TIMEOUT_MS: 600000,
-      MAX_OUTBOUND_LIMIT: GenesisParams.consensus.MAX_NUM_VALIDATORS - 1,
-      MAX_INBOUND_LIMIT: GenesisParams.consensus.MAX_NUM_VALIDATORS - 1,
+      MAX_NUM_PEER_CANDIDATES_AT_ONCE: 2,
       DEFAULT_MAX_OUTBOUND: GenesisParams.consensus.MAX_NUM_VALIDATORS - 1,
       DEFAULT_MAX_INBOUND: GenesisParams.consensus.MAX_NUM_VALIDATORS - 1
     }
@@ -691,7 +744,7 @@ function getGenesisValues() {
   CommonUtil.setJsObject(
       values, [PredefinedDbPaths.SHARDING, PredefinedDbPaths.SHARDING_CONFIG], GenesisSharding);
   CommonUtil.setJsObject(
-      values, [PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.WHITELIST], GenesisParams.consensus.GENESIS_WHITELIST);
+      values, [PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.CONSENSUS_WHITELIST], GenesisParams.consensus.GENESIS_WHITELIST);
   return values;
 }
 
@@ -710,7 +763,7 @@ function getGenesisRules() {
 }
 
 function getGenesisOwners() {
-  let owners = getGenesisConfig('genesis_owners.json', process.env.ADDITIONAL_OWNERS);
+  const owners = getGenesisConfig('genesis_owners.json', process.env.ADDITIONAL_OWNERS);
   CommonUtil.setJsObject(owners, [], getRootOwner());
   if (GenesisSharding[ShardingProperties.SHARDING_PROTOCOL] !== ShardingProtocols.NONE) {
     CommonUtil.setJsObject(
@@ -718,7 +771,7 @@ function getGenesisOwners() {
         getShardingOwner());
   }
   CommonUtil.setJsObject(
-      owners, [PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.WHITELIST], getWhitelistOwner());
+      owners, [PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.CONSENSUS_WHITELIST], getWhitelistOwner());
   return owners;
 }
 
@@ -806,7 +859,6 @@ module.exports = {
   ENABLE_DEV_SET_CLIENT_API,
   ENABLE_TX_SIG_VERIF_WORKAROUND,
   ENABLE_GAS_FEE_WORKAROUND,
-  COMCOM_HOST_EXTERNAL_IP,
   ACCOUNT_INDEX,
   PORT,
   P2P_PORT,
@@ -832,6 +884,7 @@ module.exports = {
   BlockchainNodeStates,
   PredefinedDbPaths,
   TokenProperties,
+  TokenBridgeProperties,
   AccountProperties,
   OwnerProperties,
   RuleProperties,
diff --git a/common/network-util.js b/common/network-util.js
index 1885b1062..64b1fe300 100644
--- a/common/network-util.js
+++ b/common/network-util.js
@@ -2,7 +2,8 @@ const _ = require('lodash');
 const axios = require('axios');
 const logger = require('../logger')('NETWORK-UTIL');
 const {
-  CURRENT_PROTOCOL_VERSION
+  CURRENT_PROTOCOL_VERSION,
+  CHAIN_ID
 } = require('../common/constants');
 const CommonUtil = require('../common/common-util');
 
@@ -60,7 +61,7 @@ async function sendSignedTx(endpoint, params) {
 
 // FIXME(minsulee2): this is duplicated function see: ./tools/util.js
 async function signAndSendTx(endpoint, tx, privateKey) {
-  const { txHash, signedTx } = CommonUtil.signTransaction(tx, privateKey);
+  const { txHash, signedTx } = CommonUtil.signTransaction(tx, privateKey, CHAIN_ID);
   const result = await sendSignedTx(endpoint, signedTx);
   return Object.assign(result, { txHash });
 }
diff --git a/common/path-util.js b/common/path-util.js
index ee6513280..af198efbb 100644
--- a/common/path-util.js
+++ b/common/path-util.js
@@ -37,12 +37,25 @@ class PathUtil {
     return `${PathUtil.getServiceAccountPathFromAccountName(accountName)}/${PredefinedDbPaths.BALANCE}`;
   }
 
+  static getTokenBridgeConfigPath(type, tokenId) {
+    return CommonUtil.formatPath([PredefinedDbPaths.TOKEN, PredefinedDbPaths.TOKEN_BRIDGE, type, tokenId]);
+  }
+
+  static getTokenBridgeTokenPoolPath(type, tokenId) {
+    return CommonUtil.formatPath([
+        PredefinedDbPaths.TOKEN, PredefinedDbPaths.TOKEN_BRIDGE, type, tokenId, PredefinedDbPaths.TOKEN_BRIDGE_TOKEN_POOL]);
+  }
+
+  static getTransferPath(from, to, key) {
+    return CommonUtil.formatPath([PredefinedDbPaths.TRANSFER, from, to, key]);
+  }
+
   static getTransferValuePath(from, to, key) {
-    return CommonUtil.formatPath([PredefinedDbPaths.TRANSFER, from, to, key, PredefinedDbPaths.TRANSFER_VALUE]);
+    return CommonUtil.appendPath(PathUtil.getTransferPath(from, to, key), PredefinedDbPaths.TRANSFER_VALUE);
   }
 
   static getTransferResultPath(from, to, key) {
-    return CommonUtil.formatPath([PredefinedDbPaths.TRANSFER, from, to, key, PredefinedDbPaths.TRANSFER_RESULT]);
+    return CommonUtil.appendPath(PathUtil.getTransferPath(from, to, key), PredefinedDbPaths.TRANSFER_RESULT);
   }
 
   static getCreateAppRecordPath(appName, recordId) {
@@ -58,6 +71,10 @@ class PathUtil {
     return CommonUtil.formatPath([PredefinedDbPaths.MANAGE_APP, appName, PredefinedDbPaths.MANAGE_APP_CONFIG]);
   }
 
+  static getManageAppConfigAdminPath(appName) {
+    return `${PathUtil.getManageAppConfigPath(appName)}/${PredefinedDbPaths.MANAGE_APP_CONFIG_ADMIN}`;
+  }
+
   static getManageAppBillingUsersPath(appName, billingId) {
     return `${PathUtil.getManageAppConfigPath(appName)}/${PredefinedDbPaths.MANAGE_APP_CONFIG_BILLING}/` +
         `${billingId}/${PredefinedDbPaths.MANAGE_APP_CONFIG_BILLING_USERS}`;
@@ -187,12 +204,59 @@ class PathUtil {
     return PathUtil.getCheckinPayloadPath(branchPath);
   }
 
+  static getCheckoutRequestPath(address, checkoutId) {
+    return CommonUtil.formatPath([
+        PredefinedDbPaths.CHECKOUT, PredefinedDbPaths.CHECKOUT_REQUESTS, address, checkoutId]);
+  }
+
+  static getCheckoutHistoryPath(address, checkoutId) {
+    return CommonUtil.formatPath([
+        PredefinedDbPaths.CHECKOUT, PredefinedDbPaths.CHECKOUT_HISTORY, address, checkoutId]);
+  }
+
+  static getCheckoutHistoryRefundPath(address, checkoutId) {
+    return CommonUtil.appendPath(
+        PathUtil.getCheckoutHistoryPath(address, checkoutId), PredefinedDbPaths.CHECKOUT_HISTORY_REFUND);
+  }
+
+  static getCheckoutPendingAmountTotalPath() {
+    return CommonUtil.formatPath([
+        PredefinedDbPaths.CHECKOUT, PredefinedDbPaths.CHECKOUT_STATS,
+        PredefinedDbPaths.CHECKOUT_STATS_PENDING, PredefinedDbPaths.CHECKOUT_STATS_TOTAL]);
+  }
+
+  static getCheckoutPendingAmountForAddrPath(address) {
+    return CommonUtil.formatPath([
+        PredefinedDbPaths.CHECKOUT, PredefinedDbPaths.CHECKOUT_STATS,
+        PredefinedDbPaths.CHECKOUT_STATS_PENDING, address]);
+  }
+
+  static getCheckoutCompleteAmountTotalPath() {
+    return CommonUtil.formatPath([
+        PredefinedDbPaths.CHECKOUT, PredefinedDbPaths.CHECKOUT_STATS,
+        PredefinedDbPaths.CHECKOUT_STATS_COMPLETE, PredefinedDbPaths.CHECKOUT_STATS_TOTAL]);
+  }
+
+  static getCheckoutCompleteAmountDailyPath(dayTimestamp) {
+    return CommonUtil.formatPath([
+        PredefinedDbPaths.CHECKOUT, PredefinedDbPaths.CHECKOUT_STATS,
+        PredefinedDbPaths.CHECKOUT_STATS_COMPLETE, dayTimestamp]);
+  }
+
+  static getConsensusOffenseRecordsPath() {
+    return CommonUtil.formatPath([PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.CONSENSUS_OFFENSE_RECORDS]);
+  }
+
+  static getConsensusOffenseRecordsAddrPath(address) {
+    return CommonUtil.formatPath([PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.CONSENSUS_OFFENSE_RECORDS, address]);
+  }
+
   static getConsensusWhitelistPath() {
-    return CommonUtil.formatPath([PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.WHITELIST]);
+    return CommonUtil.formatPath([PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.CONSENSUS_WHITELIST]);
   }
 
   static getConsensusWhitelistAddrPath(address) {
-    return CommonUtil.formatPath([PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.WHITELIST, address]);
+    return CommonUtil.formatPath([PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.CONSENSUS_WHITELIST, address]);
   }
 
   static getConsensusStakingAccountPath(address) {
@@ -204,19 +268,41 @@ class PathUtil {
     return CommonUtil.appendPath(accountPath, PredefinedDbPaths.BALANCE)
   }
 
+  static getConsensusRewardsPath(address) {
+    return CommonUtil.formatPath([PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.CONSENSUS_REWARDS, address]);
+  }
+
+  static getConsensusRewardsUnclaimedPath(address) {
+    return CommonUtil.formatPath([PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.CONSENSUS_REWARDS, address, PredefinedDbPaths.CONSENSUS_REWARDS_UNCLAIMED]);
+  }
+
+  static getConsensusRewardsCumulativePath(address) {
+    return CommonUtil.formatPath([PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.CONSENSUS_REWARDS, address, PredefinedDbPaths.CONSENSUS_REWARDS_CUMULATIVE]);
+  }
+
+  static getConsensusNumberPath(blockNumber) {
+    return CommonUtil.formatPath([PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.CONSENSUS_NUMBER, blockNumber]);
+  }
+
   static getConsensusProposePath(blockNumber) {
     return CommonUtil.formatPath([
-        PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.NUMBER, blockNumber, PredefinedDbPaths.PROPOSE]);
+        PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.CONSENSUS_NUMBER, blockNumber, PredefinedDbPaths.CONSENSUS_PROPOSE]);
+  }
+
+  static getConsensusVotePath(blockNumber, blockHash, address) {
+    return CommonUtil.formatPath([
+        PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.CONSENSUS_NUMBER, blockNumber, blockHash,
+        PredefinedDbPaths.CONSENSUS_VOTE, address]);
   }
 
-  static getConsensusVotePath(blockNumber, address) {
+  static getGasFeeClaimPath(userAddr, recordId) {
     return CommonUtil.formatPath([
-        PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.NUMBER, blockNumber, PredefinedDbPaths.VOTE, address]);
+        PredefinedDbPaths.GAS_FEE, PredefinedDbPaths.GAS_FEE_CLAIM, userAddr, recordId]);
   }
 
-  static getGasFeeCollectPath(userAddr, blockNumber, txHash) {
+  static getGasFeeCollectPath(blockNumber, userAddr, txHash) {
     return CommonUtil.formatPath([
-        PredefinedDbPaths.GAS_FEE, PredefinedDbPaths.COLLECT, userAddr, blockNumber, txHash]);
+        PredefinedDbPaths.GAS_FEE, PredefinedDbPaths.GAS_FEE_COLLECT, blockNumber, userAddr, txHash]);
   }
 
   static getReceiptPath(txHash) {
diff --git a/consensus/block-pool.js b/consensus/block-pool.js
index 993794ab9..473b611fd 100644
--- a/consensus/block-pool.js
+++ b/consensus/block-pool.js
@@ -1,8 +1,10 @@
-const get = require('lodash/get');
+const _get = require('lodash/get');
 const logger = require('../logger')('BLOCK_POOL');
-const { ConsensusConsts } = require('./constants');
-const { WriteDbOperations } = require('../common/constants');
+const { ConsensusConsts, ValidatorOffenseTypes } = require('./constants');
+const { StateVersions } = require('../common/constants');
 const CommonUtil = require('../common/common-util');
+const ConsensusUtil = require('./consensus-util');
+const Transaction = require('../tx-pool/transaction');
 
 class BlockPool {
   constructor(node, lastBlock) {
@@ -10,18 +12,21 @@ class BlockPool {
     const lastFinalizedBlock = this.node.bc.lastBlock();
 
     // Mapping of a block hash to the block's info (block, proposal tx, voting txs)
-    // e.g. { block_hash: { block, proposal, votes: { address: stake } } }
+    // e.g. { [<blockHash>]: { block, proposal, votes: { [<address>]: <number> }, tallied } }
     this.hashToBlockInfo = {};
+    // Mapping of a block hash to the invalid block's info.
+    // e.g. { [<blockHash>]: { block, proposal, votes: { [<address>]: <number> } } }
+    this.hashToInvalidBlockInfo = {};
     // Mapping of a block hash to the new db state
     this.hashToDb = new Map();
     // Mapping of a block hash to a set of block hashes that extend the block.
-    // e.g. { block_hash: Set<block_hash> }
+    // e.g. { [<blockHash>]: Set<blockHash> }
     this.hashToNextBlockSet = {};
     // Mapping of an epoch to the hash of a block proposed at the epoch.
-    // e.g. { epoch: block_hash }
+    // e.g. { [<epoch>]: <blockHash> }
     this.epochToBlock = {};
     // Mapping of a number to a set of block hashes proposed for the number.
-    // e.g. { number: Set<block_hash> }
+    // e.g. { [<blockNumber>]: Set<blockHash> }
     this.numberToBlockSet = {};
 
     this.longestNotarizedChainTips = [lastFinalizedBlock.hash];
@@ -37,7 +42,7 @@ class BlockPool {
       const lastBlockEpoch = lastBlock.epoch;
       const lastBlockNumber = lastBlock.number;
       if (lastFinalizedBlock && lastFinalizedBlock.hash === lastBlock.last_hash) {
-        const proposal = BlockPool.filterProposal(lastBlock.last_votes);
+        const proposal = ConsensusUtil.filterProposalFromVotes(lastBlock.last_votes);
         this.hashToBlockInfo[lastFinalizedBlockHash] = {
           block: lastFinalizedBlock,
           proposal,
@@ -61,7 +66,7 @@ class BlockPool {
   updateLongestNotarizedChains() {
     const LOG_HEADER = 'updateLongestNotarizedChains';
     const currentLongest = this.longestNotarizedChainTips.length ?
-        get(this.hashToBlockInfo[this.longestNotarizedChainTips[0]], 'block.number')
+        _get(this.hashToBlockInfo[this.longestNotarizedChainTips[0]], 'block.number')
         : this.node.bc.lastBlockNumber();
     if (currentLongest == undefined) {
       logger.error(`[${LOG_HEADER}] Notarized block's info is missing: ` +
@@ -76,19 +81,26 @@ class BlockPool {
     }, []);
   }
 
-  getExtendingChain(blockHash, withInfo = false) {
+  getExtendingChain(blockHash, withInfo = false, withRecordedInvalidBlockHashSet = false) {
     const LOG_HEADER = 'getExtendingChain';
     const chain = [];
+    const recordedInvalidBlockHashSet = new Set();
     const finalizedBlock = this.node.bc.lastBlock();
     let currBlockWithInfo = this.hashToBlockInfo[blockHash];
     if (!currBlockWithInfo || !currBlockWithInfo.block ||
         currBlockWithInfo.block.number <= finalizedBlock.number) {
-      return [];
+      return { chain, recordedInvalidBlockHashSet };
     }
     while (currBlockWithInfo && currBlockWithInfo.block &&
         currBlockWithInfo.block.number > finalizedBlock.number) {
-      chain.unshift(withInfo ? currBlockWithInfo : currBlockWithInfo.block);
-      currBlockWithInfo = this.hashToBlockInfo[currBlockWithInfo.block.last_hash];
+      const block = currBlockWithInfo.block;
+      chain.unshift(withInfo ? currBlockWithInfo : block);
+      if (withRecordedInvalidBlockHashSet) {
+        for (const invalidBlockHash of ConsensusUtil.getInvalidBlockHashesFromBlock(block)) {
+          recordedInvalidBlockHashSet.add(invalidBlockHash);
+        }
+      }
+      currBlockWithInfo = this.hashToBlockInfo[block.last_hash];
     }
     logger.debug(`[${LOG_HEADER}] currBlockWithInfo: ` +
         `${JSON.stringify(currBlockWithInfo, null, 2)}` +
@@ -101,7 +113,7 @@ class BlockPool {
       logger.error(`[${LOG_HEADER}] Incorrect chain`);
       return [];
     }
-    return chain;
+    return { chain, recordedInvalidBlockHashSet };
   }
 
   getLongestNotarizedChainList(fromBlock, withInfo = false) {
@@ -215,16 +227,19 @@ class BlockPool {
     return blockInfo && blockInfo.block && blockInfo.notarized ? blockInfo.block : null;
   }
 
-  hasSeenBlock(block) {
-    const blockInfo = this.hashToBlockInfo[block.hash];
-    return blockInfo && blockInfo.block && (blockInfo.block.number === 0 || blockInfo.proposal);
+  hasSeenBlock(blockHash) {
+    if (this.hashToBlockInfo[blockHash]) {
+      const blockInfo = this.hashToBlockInfo[blockHash];
+      return blockInfo && blockInfo.block && (blockInfo.block.number === 0 || !!blockInfo.proposal);
+    } else if (this.hashToInvalidBlockInfo[blockHash]) {
+      const blockInfo = this.hashToInvalidBlockInfo[blockHash];
+      return blockInfo && blockInfo.block && (blockInfo.block.number === 0 || !!blockInfo.proposal);
+    }
+    return false;
   }
 
-  addSeenBlock(block, proposalTx) {
-    const LOG_HEADER = 'addSeenBlock';
-
-    logger.info(
-        `[${LOG_HEADER}] Adding seen block to the block pool: ${block.number} / ${block.epoch}`);
+  checkEpochToBlockMap(block) {
+    const LOG_HEADER = 'checkEpochToBlockMap';
     // Check that there's no other block proposed at the same epoch
     if (this.epochToBlock[block.epoch] && this.epochToBlock[block.epoch] !== block.hash) {
       const conflict = this.hashToBlockInfo[this.epochToBlock[block.epoch]];
@@ -237,7 +252,11 @@ class BlockPool {
           `${block.epoch} (${block.hash}, ${this.epochToBlock[block.epoch]}) BUT is not notarized`);
       // FIXME: remove info about the block that's currently this.epochToBlock[block.epoch] ?
     }
-    // Update hashToBlockInfo
+    return true;
+  }
+
+  addToHashBlockInfoMap(block, proposalTx) {
+    const LOG_HEADER = 'addToHashBlockInfoMap';
     const blockHash = block.hash;
     if (!this.hashToBlockInfo[blockHash]) {
       this.hashToBlockInfo[blockHash] = {};
@@ -251,7 +270,7 @@ class BlockPool {
         this.hashToBlockInfo[blockHash].tallied = 0;
         blockInfo.votes.forEach((vote) => {
           if (block.validators[vote.address]) {
-            this.hashToBlockInfo[blockHash].tallied += get(vote, 'tx_body.operation.value.stake');
+            this.hashToBlockInfo[blockHash].tallied += _get(vote, 'tx_body.operation.value.stake');
           }
         });
         this.tryUpdateNotarized(blockHash);
@@ -262,66 +281,152 @@ class BlockPool {
       logger.info(
           `[${LOG_HEADER}] Block already in the block pool: ${block.number} / ${block.epoch}`);
     }
+  }
 
-    this.epochToBlock[block.epoch] = blockHash;
+  addToInvalidBlockInfoMap(block, proposalTx) {
+    const LOG_HEADER = 'addToInvalidBlockInfoMap';
+    const blockHash = block.hash;
+    if (!this.hashToInvalidBlockInfo[blockHash]) {
+      this.hashToInvalidBlockInfo[blockHash] = {};
+    }
+    const blockInfo = this.hashToInvalidBlockInfo[blockHash];
+    if (CommonUtil.isEmpty(blockInfo.block)) {
+      this.hashToInvalidBlockInfo[blockHash].block = block;
+      this.hashToInvalidBlockInfo[blockHash].proposal = proposalTx;
+      logger.info(
+          `[${LOG_HEADER}] Invalid block added to the block pool: ${block.number} / ${block.epoch}`);
+    } else {
+      logger.info(
+          `[${LOG_HEADER}] Invalid block already in the block pool: ${block.number} / ${block.epoch}`);
+    }
+  }
 
+  addToNumberToBlockSet(block) {
     if (!this.numberToBlockSet[block.number]) {
       this.numberToBlockSet[block.number] = new Set();
     }
     this.numberToBlockSet[block.number].add(block.hash);
+  }
 
+  addToNextBlockSet(block) {
     const lastHash = block.last_hash;
     if (!this.hashToNextBlockSet[lastHash]) {
       this.hashToNextBlockSet[lastHash] = new Set();
     }
-    this.hashToNextBlockSet[lastHash].add(blockHash);
+    this.hashToNextBlockSet[lastHash].add(block.hash);
+  }
 
-    // Try updating notarized info for block and next block (if applicable)
-    this.tryUpdateNotarized(blockHash);
-    // FIXME: update all descendants, not just the immediate ones
-    if (this.hashToNextBlockSet[blockHash]) {
-      for (const val of this.hashToNextBlockSet[blockHash]) {
-        this.tryUpdateNotarized(val);
+  addSeenBlock(block, proposalTx, isValid = true) {
+    const LOG_HEADER = 'addSeenBlock';
+    logger.info(
+        `[${LOG_HEADER}] Adding seen block to the block pool: ${block.number} / ${block.epoch} / ${isValid}`);
+    const blockHash = block.hash;
+    if (isValid) {
+      if (!this.checkEpochToBlockMap(block)) {
+        return false;
+      }
+      this.addToHashBlockInfoMap(block, proposalTx);
+      this.addToNumberToBlockSet(block);
+      this.epochToBlock[block.epoch] = blockHash;
+      this.addToNextBlockSet(block);
+      this.tryUpdateNotarized(blockHash);
+      // FIXME: update all descendants, not just the immediate ones
+      if (this.hashToNextBlockSet[blockHash]) {
+        for (const val of this.hashToNextBlockSet[blockHash]) {
+          this.tryUpdateNotarized(val);
+        }
       }
+    } else {
+      this.addToInvalidBlockInfoMap(block, proposalTx);
+      this.addToNumberToBlockSet(block);
     }
     return true;
   }
 
-  addSeenVote(voteTx, currentEpoch) {
+  hasVote(voteTx, blockHash, isAgainstVote) {
+    if (isAgainstVote) {
+      if (!this.hashToInvalidBlockInfo[blockHash] || !this.hashToInvalidBlockInfo[blockHash].votes) {
+        return false;
+      }
+      return !!this.hashToInvalidBlockInfo[blockHash].votes.find((v) => v.hash === voteTx.hash);
+    } else {
+      if (!this.hashToBlockInfo[blockHash] || !this.hashToBlockInfo[blockHash].votes) {
+        return false;
+      }
+      return !!this.hashToBlockInfo[blockHash].votes.find((v) => v.hash === voteTx.hash);
+    }
+  }
+
+  addSeenVote(voteTx) {
     const LOG_HEADER = 'addSeenVote';
-    const blockHash = get(voteTx, 'tx_body.operation.value.block_hash');
-    const stake = get(voteTx, 'tx_body.operation.value.stake');
+    const blockHash = ConsensusUtil.getBlockHashFromConsensusTx(voteTx);
+    const stake = ConsensusUtil.getStakeFromVoteTx(voteTx);
     logger.debug(`[${LOG_HEADER}] voteTx: ${JSON.stringify(voteTx, null, 2)}, ` +
         `blockHash: ${blockHash}, stake: ${stake}`);
+    if (ConsensusUtil.isProposalTx(voteTx)) {
+      this.addProposal(voteTx, blockHash);
+    } else if (ConsensusUtil.isAgainstVoteTx(voteTx)) {
+      this.addVoteAgainst(voteTx, blockHash);
+    } else {
+      this.addVoteFor(voteTx, blockHash, stake);
+    }
+  }
+
+  addVoteFor(voteTx, blockHash, stake) {
+    const LOG_HEADER = 'addVoteFor';
     if (!this.hashToBlockInfo[blockHash]) {
       this.hashToBlockInfo[blockHash] = {};
     }
     if (!this.hashToBlockInfo[blockHash].votes) {
       this.hashToBlockInfo[blockHash].votes = [];
     }
-    if (this.hashToBlockInfo[blockHash].votes.filter((v) => v.hash === voteTx.hash).length) {
-      logger.info(`[${LOG_HEADER}] we've already seen this vote`);
+    if (this.hasVote(voteTx, blockHash, false)) {
+      logger.debug(`[${LOG_HEADER}] Already have seen this vote`);
       return;
     }
+    this.hashToBlockInfo[blockHash].votes.push(voteTx);
     if (this.hashToBlockInfo[blockHash].tallied === undefined) {
       this.hashToBlockInfo[blockHash].tallied = 0;
     }
-    this.hashToBlockInfo[blockHash].votes.push(voteTx);
     // Only counts if the voter was actually included as a validator in the block.
     // To know this, we need the block itself.
     const block = this.hashToBlockInfo[blockHash].block;
-    if (currentEpoch && block && block.epoch < currentEpoch) {
-      logger.info(`[${LOG_HEADER}] Possibly a stale vote (${block.epoch} / ${currentEpoch})`);
-      // FIXME
-    }
     const voter = voteTx.address;
-    logger.debug(`[${LOG_HEADER}] voted block: ${JSON.stringify(block, null, 2)}`);
-    if (stake > 0 && block && get(block, `validators.${voter}.stake`) === stake) {
+    logger.debug(`[${LOG_HEADER}] Voted for block: ${blockHash}`);
+    if (stake > 0 && block && _get(block, `validators.${voter}.stake`) === stake) {
       this.hashToBlockInfo[blockHash].tallied += stake;
       this.tryUpdateNotarized(blockHash);
     }
   }
 
+  addVoteAgainst(voteTx, blockHash) {
+    const LOG_HEADER = 'addVoteAgainst';
+    if (!this.hashToInvalidBlockInfo[blockHash]) {
+      this.hashToInvalidBlockInfo[blockHash] = {};
+    }
+    if (!this.hashToInvalidBlockInfo[blockHash].votes) {
+      this.hashToInvalidBlockInfo[blockHash].votes = [];
+    }
+    if (this.hasVote(voteTx, blockHash, true)) {
+      logger.debug(`[${LOG_HEADER}] Already have seen this vote`);
+      return;
+    }
+    this.hashToInvalidBlockInfo[blockHash].votes.push(voteTx);
+    logger.debug(`[${LOG_HEADER}] Voted against block: ${blockHash}`);
+  }
+
+  addProposal(proposalTx, blockHash) {
+    const LOG_HEADER = 'addProposal';
+    if (!this.hashToInvalidBlockInfo[blockHash]) {
+      this.hashToInvalidBlockInfo[blockHash] = {};
+    } else if (this.hashToInvalidBlockInfo[blockHash].proposal) {
+      logger.debug(`[${LOG_HEADER}] Already have seen this proposal`);
+      return;
+    }
+    this.hashToInvalidBlockInfo[blockHash].proposal = proposalTx;
+    logger.debug(`[${LOG_HEADER}] Proposal tx for block added: ${blockHash}`);
+  }
+
   tryUpdateNotarized(blockHash) {
     const LOG_HEADER = 'tryUpdateNotarized';
     const currentBlockInfo = this.hashToBlockInfo[blockHash];
@@ -336,7 +441,7 @@ class BlockPool {
     if (lastBlockNumber === lastFinalizedBlock.number) {
       prevBlock = lastFinalizedBlock;
     } else if (lastBlockNumber > lastFinalizedBlock.number) {
-      prevBlock = get(this.hashToBlockInfo[lastHash], 'block');
+      prevBlock = _get(this.hashToBlockInfo[lastHash], 'block');
     } else {
       prevBlock = this.node.bc.getBlockByHash(lastHash);
     }
@@ -345,7 +450,7 @@ class BlockPool {
       return;
     }
     const totalAtStake = Object.values(prevBlock.validators).reduce((acc, cur) => {
-      return acc + get(cur, 'stake', 0);
+      return acc + _get(cur, 'stake', 0);
     }, 0);
     if (currentBlockInfo.tallied &&
         currentBlockInfo.tallied >= totalAtStake * ConsensusConsts.MAJORITY) {
@@ -358,6 +463,7 @@ class BlockPool {
 
   cleanUpForBlockHash(blockHash) {
     delete this.hashToBlockInfo[blockHash];
+    delete this.hashToInvalidBlockInfo[blockHash];
     delete this.hashToNextBlockSet[blockHash];
     const db = this.hashToDb.get(blockHash);
     if (db) {
@@ -367,14 +473,25 @@ class BlockPool {
   }
 
   // Remove everything that came before lastBlock including lastBlock.
-  cleanUpAfterFinalization(lastBlock) {
+  cleanUpAfterFinalization(lastBlock, recordedInvalidBlocks) {
     const targetNumber = lastBlock.number;
     Object.keys(this.numberToBlockSet).forEach((blockNumber) => {
       if (blockNumber < targetNumber) {
         this.numberToBlockSet[blockNumber].forEach((blockHash) => {
-          this.cleanUpForBlockHash(blockHash);
+          if (this.hashToInvalidBlockInfo[blockHash]) {
+            if (recordedInvalidBlocks.has(blockHash) ||
+                blockNumber < targetNumber - ConsensusConsts.MAX_CONSENSUS_STATE_DB) {
+              this.cleanUpForBlockHash(blockHash);
+              this.numberToBlockSet[blockNumber].delete(blockHash);
+            }
+          } else {
+            this.cleanUpForBlockHash(blockHash);
+            this.numberToBlockSet[blockNumber].delete(blockHash);
+          }
         });
-        delete this.numberToBlockSet[blockNumber];
+        if (!this.numberToBlockSet[blockNumber].size) {
+          delete this.numberToBlockSet[blockNumber];
+        }
       }
     });
     Object.keys(this.epochToBlock).forEach((epoch) => {
@@ -387,37 +504,121 @@ class BlockPool {
     this.updateLongestNotarizedChains();
   }
 
-  static filterProposal(votes) {
-    if (!votes) return null;
-    const proposalSuffix = 'propose';
-    const proposal = votes.filter((tx) => {
-      if (tx.tx_body.operation.type === WriteDbOperations.SET_VALUE) {
-        return tx.tx_body.operation.ref.endsWith(proposalSuffix);
-      } else if (tx.tx_body.operation.type === WriteDbOperations.SET) {
-        return tx.tx_body.operation.op_list[0].ref.endsWith(proposalSuffix);
+  /**
+   * Executes votes for the lastBlock, check that the sum of stakes exceeds the majority,
+   * and returns valid votes.
+   * @param {Block} lastBlock The block to get the votes for
+   * @param {number} blockNumber The block number of the new block
+   * @param {DB} tempDb The DB to execute the votes on
+   * @returns Array
+   */
+  getValidLastVotes(lastBlock, blockNumber, blockTime, tempDb) {
+    const LOG_HEADER = 'getValidLastVotes';
+    const lastBlockInfo = this.hashToBlockInfo[lastBlock.hash];
+    logger.debug(`[${LOG_HEADER}] lastBlockInfo: ${JSON.stringify(lastBlockInfo, null, 2)}`);
+    // FIXME(minsulee2 or liayoo): When I am behind and a newly coming node is ahead of me,
+    // then I cannot get lastBlockInfo from the block-pool. So that, it is not able to create
+    // a proper block proposal and also cannot pass checkProposal()
+    // where checking prevBlockInfo.notarized.
+    const validLastVotes = [];
+    const lastVotes = blockNumber > 1 && lastBlockInfo.votes ?
+        JSON.parse(JSON.stringify(lastBlockInfo.votes)) : [];
+    if (lastBlockInfo && lastBlockInfo.proposal) {
+      lastVotes.unshift(lastBlockInfo.proposal);
+    }
+    const majority = ConsensusUtil.getTotalAtStake(lastBlock.validators) * ConsensusConsts.MAJORITY;
+    let tallied = 0;
+    for (const vote of lastVotes) {
+      if (CommonUtil.isFailedTx(tempDb.executeTransaction(
+          Transaction.toExecutable(vote), true, true, 0, blockTime))) {
+        logger.debug(`[${LOG_HEADER}] failed to execute last vote: ${JSON.stringify(vote, null, 2)}`);
+      } else {
+        tallied += _get(lastBlock.validators, `${vote.address}.stake`, 0);
+        validLastVotes.push(vote);
       }
-      return false;
-    });
-    return proposal.length ? proposal[0] : null;
-  }
-
-  static getBlockNumberFromTx(tx) {
-    if (!tx || !tx.tx_body.operation) return null;
-    const ref = tx.tx_body.operation.ref ?
-        tx.tx_body.operation.ref : get(tx, 'tx_body.operation.op_list')[0].ref;
-    const refSplit = ref ? ref.split('/') : [];
-    return refSplit.length > 3 ? refSplit[3] : null;
+    }
+    if (blockNumber <= 1 || tallied >= majority) {
+      return validLastVotes;
+    }
+    tempDb.destroyDb();
+    throw Error(`[${LOG_HEADER}] lastBlock doesn't have enough votes`);
   }
 
-  static getBlockHashFromTx(tx) {
-    if (!tx || !tx.tx_body.operation) return null;
-    if (tx.tx_body.operation.type === WriteDbOperations.SET_VALUE) {
-      return get(tx.tx_body.operation, 'value.block_hash');
-    } else if (tx.tx_body.operation.type === WriteDbOperations.SET) {
-      return get(tx.tx_body.operation.op_list[0], 'value.block_hash');
-    } else {
-      return null;
+  /**
+   * Checks if there's any evidence in hashToInvalidBlockInfo that can sufficiently
+   * (i.e. sum of evidence votes stakes > 2/3 * total stakes) support offenses.
+   * Executes the valid evidence votes on baseDb, making changes to the state.
+   * Resulting `offenses` has the following structure: { [<address>]: { [<offenseType>]: <number> } },
+   * and the `evidence` has the following structure: { [<address>]: [{ offense_type, transactions, block, votes }, ...] }
+   * @param {object} validators The validators of the block that the offenses and evidence will be included in.
+   * @param {Set} recordedInvalidBlockHashSet A set of invalid block hashes that have been alraedy included in the chain that new block will extend.
+   * @param {DB} baseDb The DB instance should be the base of where evidence votes should be executed on.
+   * @returns { offenses, evidence }
+   */
+  getOffensesAndEvidence(validators, recordedInvalidBlockHashSet, blockTime, baseDb) {
+    const LOG_HEADER = 'getOffensesAndEvidence';
+    const totalAtStake = ConsensusUtil.getTotalAtStake(validators);
+    const blockNumber = baseDb.blockNumberSnapshot;
+    let backupDb = this.node.createTempDb(
+        baseDb.stateVersion, `${StateVersions.SNAP}:${blockNumber}`, blockNumber);
+    const majority = totalAtStake * ConsensusConsts.MAJORITY;
+    const evidence = {};
+    const offenses = {};
+    for (const [blockHash, blockInfo] of Object.entries(this.hashToInvalidBlockInfo)) {
+      if (recordedInvalidBlockHashSet.has(blockHash)) {
+        continue;
+      }
+      if (!blockInfo.votes || !blockInfo.votes.length) {
+        continue;
+      }
+      const validBlockCandidate = this.hashToBlockInfo[blockHash];
+      const block = blockInfo.block || _get(validBlockCandidate, 'block');
+      const proposal = blockInfo.proposal || _get(validBlockCandidate, 'proposal');
+      if (!block || !proposal) {
+        continue;
+      }
+      const talliedVotes = [];
+      let talliedAgainst = 0;
+      for (const vote of blockInfo.votes) {
+        const stake = _get(validators, `${vote.address}.stake`, 0);
+        if (stake > 0) {
+          const res = baseDb.executeTransaction(Transaction.toExecutable(vote), true, true, 0, blockTime);
+          if (CommonUtil.isFailedTx(res)) {
+            logger.debug(`[${LOG_HEADER}] Failed to execute evidence vote:\n${JSON.stringify(vote, null, 2)}\n${JSON.stringify(res, null, 2)})`);
+          } else {
+            talliedAgainst += stake;
+            talliedVotes.push(vote);
+          }
+        }
+      }
+      if (talliedAgainst >= majority) {
+        const offender = block.proposer;
+        if (!evidence[offender]) {
+          evidence[offender] = [];
+        }
+        if (!offenses[offender]) {
+          offenses[offender] = {
+            [ValidatorOffenseTypes.INVALID_PROPOSAL]: 0
+          };
+        }
+        evidence[offender].push({
+          transactions: [proposal],
+          block: block,
+          votes: talliedVotes,
+          offense_type: ValidatorOffenseTypes.INVALID_PROPOSAL
+        });
+        offenses[offender][ValidatorOffenseTypes.INVALID_PROPOSAL] += 1;
+      } else {
+        const newBackupDb = this.node.createTempDb(
+            backupDb.stateVersion, `${StateVersions.SNAP}:${blockNumber}`, blockNumber);
+        baseDb.setStateVersion(newBackupDb.stateVersion, newBackupDb.stateRoot);
+        backupDb.destroyDb();
+        backupDb = this.node.createTempDb(
+            baseDb.stateVersion, `${StateVersions.SNAP}:${blockNumber}`, blockNumber);
+      }
     }
+    backupDb.destroyDb();
+    return { offenses, evidence };
   }
 }
 
diff --git a/consensus/consensus-util.js b/consensus/consensus-util.js
new file mode 100644
index 000000000..eeb01260e
--- /dev/null
+++ b/consensus/consensus-util.js
@@ -0,0 +1,97 @@
+const _get = require('lodash/get');
+const { WriteDbOperations, PredefinedDbPaths } = require('../common/constants');
+const CommonUtil = require('../common/common-util');
+const { ConsensusErrorCodesToVoteAgainst } = require('./constants');
+
+class ConsensusUtil {
+  static isValidConsensusTx(tx) {
+    const op = _get(tx, 'tx_body.operation');
+    if (!op) return false;
+    const consensusTxPrefix = CommonUtil.formatPath(
+        [PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.CONSENSUS_NUMBER]);
+    if (op.type === WriteDbOperations.SET_VALUE) {
+      return op.ref.startsWith(consensusTxPrefix);
+    } else if (op.type === WriteDbOperations.SET) {
+      const opList = op.op_list;
+      if (!opList || opList.length !== 2) {
+        return false;
+      }
+      opList.forEach((innerOp) => {
+        if (!innerOp.ref.startsWith(consensusTxPrefix)) return false;
+      })
+      return true;
+    } else {
+      return false;
+    }
+  }
+
+  static isProposalTx(tx) {
+    const op = _get(tx, 'tx_body.operation');
+    if (!op) return false;
+    if (op.type === WriteDbOperations.SET_VALUE) {
+      return op.ref.endsWith(PredefinedDbPaths.CONSENSUS_PROPOSE);
+    } else if (op.type === WriteDbOperations.SET) {
+      return _get(op, 'op_list.0.ref', '').endsWith(PredefinedDbPaths.CONSENSUS_PROPOSE);
+    }
+    return false;
+  }
+
+  static filterProposalFromVotes(votes) {
+    if (!votes) return null;
+    const proposal = votes.filter((tx) => ConsensusUtil.isProposalTx(tx));
+    return proposal.length ? proposal[0] : null;
+  }
+
+  static getBlockHashFromConsensusTx(tx) {
+    const op = _get(tx, 'tx_body.operation');
+    if (!tx || !op) return null;
+    if (op.type === WriteDbOperations.SET_VALUE) {
+      return _get(op, 'value.block_hash');
+    } else if (op.type === WriteDbOperations.SET) {
+      return _get(op, 'op_list.0.value.block_hash');
+    } else {
+      return null;
+    }
+  }
+
+  static getStakeFromVoteTx(tx) {
+    return _get(tx, 'tx_body.operation.value.stake');
+  }
+
+  static getOffenseTypeFromVoteTx(tx) {
+    return _get(tx, 'tx_body.operation.value.offense_type');
+  }
+
+  static isAgainstVoteTx(tx) {
+    return _get(tx, 'tx_body.operation.value.is_against') === true;
+  }
+
+  static getOffensesFromProposalTx(tx) {
+    return _get(tx, 'tx_body.operation.value.offenses', {});
+  }
+
+  static getTotalAtStake(validators) {
+    return Object.values(validators).reduce((acc, cur) => {
+      return acc + _get(cur, PredefinedDbPaths.CONSENSUS_STAKE, 0);
+    }, 0);
+  }
+
+  static isVoteAgainstBlockError(errorCode) {
+    return ConsensusErrorCodesToVoteAgainst.has(errorCode);
+  }
+
+  static getInvalidBlockHashesFromBlock(block) {
+    const invalidBlockHashList = [];
+    if (CommonUtil.isEmpty(block.evidence)) {
+      return [];
+    }
+    for (const evidenceList of Object.values(block.evidence)) {
+      for (const evidenceForOffense of evidenceList) {
+        invalidBlockHashList.push(_get(evidenceForOffense, 'block.hash'));
+      }
+    }
+    return invalidBlockHashList;
+  }
+}
+
+module.exports = ConsensusUtil;
diff --git a/consensus/constants.js b/consensus/constants.js
index f2d991ff7..c244b27f7 100644
--- a/consensus/constants.js
+++ b/consensus/constants.js
@@ -2,22 +2,88 @@ const ConsensusConsts = {
   MAJORITY: 2 / 3,
   DAY_MS: 86400000,
   MAX_CONSENSUS_STATE_DB: 1000,
-  HEALTH_THRESHOLD_EPOCH: 600
-}
+  HEALTH_THRESHOLD_EPOCH: 600,
+  STAKE_LOCKUP_EXTENSION: 2592000000, // 30 days as ms
+};
 
 const ConsensusMessageTypes = {
   PROPOSE: 'propose',
-  VOTE: 'vote'
+  VOTE: 'vote',
 };
 
 const ConsensusStates = {
   STARTING: 'STARTING',
   RUNNING: 'RUNNING',
   STOPPED: 'STOPPED',
+};
+
+const ValidatorOffenseTypes = {
+  INVALID_PROPOSAL: 'INVALID_PROPOSAL',
 }
 
+const ConsensusErrorCode = {
+  PARSING_PROPOSAL_BLOCK_FAILURE: 1,
+  ADDING_TO_BLOCK_POOL_FAILURE: 2,
+  NOT_EXTENDING_LNC_ERROR: 3,
+  TEMP_DB_CREATION_FAILURE: 4,
+  RECEIVED_PROPOSAL: 100,
+  OUTDATED_BLOCK: 101,
+  PROPOSER_MISMATCH: 102,
+  BLOCK_HASH_MISMATCH: 103,
+  INVALID_VALIDATORS_SIZE: 104,
+  ILL_FORMED_BLOCK: 105,
+  INVALID_PREV_BLOCK: 200,
+  MISSING_DB_FOR_PREV_BLOCK: 201,
+  INVALID_EPOCH: 202,
+  MISSING_PROPOSAL_IN_LAST_VOTES: 203,
+  MISSING_PROPOSAL_IN_BLOCK_POOL: 204,
+  INVALID_PROPOSER: 300,
+  EXECUTING_LAST_VOTES_FAILURE: 301,
+  INVALID_LAST_VOTES_STAKES: 302,
+  OFFENSES_EVIDENCE_MISMATCH: 400,
+  INVALID_OFFENSE_TYPE: 401,
+  INVALID_EVIDENCE_VOTES_STAKES: 402,
+  EXECUTING_EVIDENCE_VOTES_FAILURE: 403,
+  INVALID_OFFENSE_COUNTS: 404,
+  EXECUTING_TX_FAILURE: 500,
+  INVALID_GAS_AMOUNT_TOTAL: 501,
+  INVALID_GAS_COST_TOTAL: 502,
+  ILL_FORMED_PROPOSAL_TX: 600,
+  EXECUTING_PROPOSAL_FAILURE: 601,
+  INVALID_STATE_PROOF_HASH: 602,
+}
+
+const ConsensusErrorCodesToVoteAgainst = new Set([
+  ConsensusErrorCode.ADDING_TO_BLOCK_POOL_FAILURE,
+  ConsensusErrorCode.MISSING_DB_FOR_PREV_BLOCK,
+  ConsensusErrorCode.INVALID_EPOCH,
+  ConsensusErrorCode.MISSING_PROPOSAL_IN_LAST_VOTES,
+  ConsensusErrorCode.EXECUTING_LAST_VOTES_FAILURE,
+  ConsensusErrorCode.INVALID_LAST_VOTES_STAKES,
+  ConsensusErrorCode.INVALID_PROPOSER,
+  ConsensusErrorCode.BLOCK_HASH_MISMATCH,
+  ConsensusErrorCode.INVALID_VALIDATORS_SIZE,
+  ConsensusErrorCode.ILL_FORMED_BLOCK,
+  ConsensusErrorCode.INVALID_PREV_BLOCK,
+  ConsensusErrorCode.INVALID_PROPOSER,
+  ConsensusErrorCode.OFFENSES_EVIDENCE_MISMATCH,
+  ConsensusErrorCode.INVALID_OFFENSE_TYPE,
+  ConsensusErrorCode.INVALID_EVIDENCE_VOTES_STAKES,
+  ConsensusErrorCode.EXECUTING_EVIDENCE_VOTES_FAILURE,
+  ConsensusErrorCode.INVALID_OFFENSE_COUNTS,
+  ConsensusErrorCode.EXECUTING_TX_FAILURE,
+  ConsensusErrorCode.INVALID_GAS_AMOUNT_TOTAL,
+  ConsensusErrorCode.INVALID_GAS_COST_TOTAL,
+  ConsensusErrorCode.ILL_FORMED_PROPOSAL_TX,
+  ConsensusErrorCode.EXECUTING_PROPOSAL_FAILURE,
+  ConsensusErrorCode.INVALID_STATE_PROOF_HASH,
+]);
+
 module.exports = {
   ConsensusMessageTypes,
   ConsensusConsts,
   ConsensusStates,
+  ValidatorOffenseTypes,
+  ConsensusErrorCode,
+  ConsensusErrorCodesToVoteAgainst,
 }
diff --git a/consensus/index.js b/consensus/index.js
index 9a08ecf24..58815d98c 100644
--- a/consensus/index.js
+++ b/consensus/index.js
@@ -27,25 +27,53 @@ const {
   MAX_STAKE_PER_VALIDATOR,
   EPOCH_MS,
   CONSENSUS_PROTOCOL_VERSION,
+  HOSTING_ENV,
 } = require('../common/constants');
 const {
   ConsensusMessageTypes,
   ConsensusConsts,
   ConsensusStates,
+  ValidatorOffenseTypes,
+  ConsensusErrorCode,
 } = require('./constants');
 const {
   signAndSendTx,
   sendGetRequest
 } = require('../common/network-util');
+const ConsensusUtil = require('./consensus-util');
 const PathUtil = require('../common/path-util');
-const DB = require('../db');
 const VersionUtil = require('../common/version-util');
+const DB = require('../db');
 
 const parentChainEndpoint = GenesisSharding[ShardingProperties.PARENT_CHAIN_POC] + '/json-rpc';
 const shardingPath = GenesisSharding[ShardingProperties.SHARDING_PATH];
 const reportingPeriod = GenesisSharding[ShardingProperties.REPORTING_PERIOD];
 const txSizeThreshold = TX_BYTES_LIMIT * 0.9;
 
+
+class ConsensusError extends Error {
+  constructor({ code, level, message }) {
+    super(message);
+    this.name = 'ConsensusException';
+    this.code = code;
+    this.level = level;
+    this.message = message;
+  }
+
+  log() {
+    switch (this.level) {
+      case 'info':
+        logger.info(this.message);
+        return;
+      case 'debug':
+        logger.debug(this.message);
+        return;
+      default:
+        logger.error(this.message);
+    }
+  }
+}
+
 class Consensus {
   constructor(server, node) {
     this.server = server;
@@ -125,7 +153,8 @@ class Consensus {
       this.isInEpochTransition = true;
       this.tryFinalize();
       let currentTime = Date.now();
-      if (this.epoch % 100 === 0) {
+      // NOTE(liayoo): temporary solution for avoiding ntp sync errors when running multiple nodes in the same machine.
+      if (HOSTING_ENV === 'gcp' && this.epoch % 100 === 0) {
         // adjust time
         try {
           const iNTPData = await ntpsync.ntpLocalClockDeltaPromise();
@@ -170,12 +199,10 @@ class Consensus {
     if (!lastNotarizedBlock) {
       logger.error(`[${LOG_HEADER}] Empty lastNotarizedBlock (${this.epoch})`);
     }
-    // Need the block#1 to be finalized to have the stakes reflected in the state
-    const validators = this.node.bc.lastBlockNumber() < 1 ? lastNotarizedBlock.validators
-        : this.getValidators(lastNotarizedBlock.hash, lastNotarizedBlock.number);
+    const validators = this.getValidators(
+        lastNotarizedBlock.hash, lastNotarizedBlock.number, this.node.stateManager.getFinalVersion());
 
     // FIXME(liayoo): Make the seeds more secure and unpredictable.
-    // const seed = '' + this.genesisHash + this.epoch;
     const seed = '' + lastNotarizedBlock.last_votes_hash + this.epoch;
     this.proposer = Consensus.selectProposer(seed, validators);
     logger.debug(`[${LOG_HEADER}] proposer for epoch ${this.epoch}: ${this.proposer}`);
@@ -220,7 +247,7 @@ class Consensus {
           `(${ConsensusStates.RUNNING})`);
       return;
     }
-    if (msg.type !== ConsensusMessageTypes.PROPOSE && msg.type !== ConsensusMessageTypes.VOTE) {
+    if (!Object.values(ConsensusMessageTypes).includes(msg.type)) {
       logger.error(`[${LOG_HEADER}] Invalid message type: ${msg.type}`);
       return;
     }
@@ -243,6 +270,10 @@ class Consensus {
         logger.debug(`[${LOG_HEADER}] Already have the proposal in my tx tracker`);
         return;
       }
+      if (this.blockPool.hasSeenBlock(proposalBlock.hash)) {
+        logger.debug(`[${LOG_HEADER}] Already have the block in my block pool`);
+        return;
+      }
       if (proposalBlock.number > lastNotarizedBlock.number + 1) {
         logger.info(`[${LOG_HEADER}] Trying to sync. Current last block number: ` +
             `${lastNotarizedBlock.number}, proposal block number ${proposalBlock.number}`);
@@ -256,132 +287,64 @@ class Consensus {
         });
         return;
       }
-      if (Consensus.isValidConsensusTx(proposalTx) &&
-          this.checkProposal(proposalBlock, proposalTx)) {
-        this.server.client.broadcastConsensusMessage(msg);
-        this.tryVote(proposalBlock);
+      if (!ConsensusUtil.isValidConsensusTx(proposalTx)) {
+        logger.info(`[${LOG_HEADER}] Invalid consensus tx: ${JSON.stringify(proposalTx)}`);
+        return;
+      }
+      try {
+        this.checkProposal(proposalBlock, proposalTx);
+      } catch (e) {
+        if (e instanceof ConsensusError) {
+          e.log();
+          if (ConsensusUtil.isVoteAgainstBlockError(e.code)) {
+            this.blockPool.addSeenBlock(proposalBlock, proposalTx, false);
+            this.server.client.broadcastConsensusMessage(msg);
+            this.tryVoteAgainstInvalidBlock(proposalBlock, proposalTx);
+          }
+        } else {
+          logger.error(`[${LOG_HEADER}] Error while checking proposal: ${e.stack}`);
+        }
+        return;
       }
+      this.server.client.broadcastConsensusMessage(msg);
+      this.tryVoteForValidBlock(proposalBlock);
     } else {
       if (this.node.tp.transactionTracker[msg.value.hash]) {
         logger.debug(`[${LOG_HEADER}] Already have the vote in my tx tracker`);
         return;
       }
-      if (Consensus.isValidConsensusTx(msg.value) && this.checkVoteTx(msg.value)) {
-        this.server.client.broadcastConsensusMessage(msg);
+      if (!ConsensusUtil.isValidConsensusTx(msg.value) || !this.checkVoteTx(msg.value)) {
+        logger.info(`[${LOG_HEADER}] Invalid vote tx: ${JSON.stringify(msg.value)}`);
+        return;
       }
+      this.server.client.broadcastConsensusMessage(msg);
     }
   }
 
-  // proposing for block #N :
-  //    1. create a block (with last_votes)
-  //    2. create a tx (/consensus/number/N/propose: { block_hash, ... })
-  //    3. broadcast tx + block (i.e. call handleConsensusMessage())
-  //    4. verify block
-  //    5. execute propose tx
-  //    6. Nth propose tx should be included in the N+1th block's last_votes
-  createProposal() {
-    const LOG_HEADER = 'createProposal';
-    const longestNotarizedChain = this.getLongestNotarizedChain();
-    const lastBlock = longestNotarizedChain && longestNotarizedChain.length ?
-        longestNotarizedChain[longestNotarizedChain.length - 1] : this.node.bc.lastBlock();
-    const blockNumber = lastBlock.number + 1;
-
-    if (blockNumber > 1 && LIGHTWEIGHT && this.cache[blockNumber]) {
-      logger.error(`Already proposed ${blockNumber} / ${this.cache[blockNumber]}`);
-      return null;
-    }
-
-    const baseVersion = lastBlock.number === this.node.bc.lastBlockNumber() ?
-        this.node.stateManager.getFinalVersion() :
-            this.blockPool.hashToDb.get(lastBlock.hash).stateVersion;
-    const tempDb = this.node.createTempDb(
-        baseVersion, `${StateVersions.CONSENSUS_CREATE}:${lastBlock.number}:${blockNumber}`,
-        lastBlock.number - 1);
-    if (!tempDb) {
-      logger.error(`Failed to create a temp database with state version: ${baseVersion}.`);
-      return null;
-    }
-    const lastBlockInfo = this.blockPool.hashToBlockInfo[lastBlock.hash];
-    logger.debug(`[${LOG_HEADER}] lastBlockInfo: ${JSON.stringify(lastBlockInfo, null, 2)}`);
-    // FIXME(minsulee2 or liayoo): When I am behind and a newly coming node is ahead of me,
-    // then I cannot get lastBlockInfo from the block-pool. So that, it is not able to create
-    // a proper block proposal and also cannot pass checkProposal()
-    // where checking prevBlockInfo.notarized.
-    const lastVotes = blockNumber > 1 && lastBlockInfo.votes ? [...lastBlockInfo.votes] : [];
-    if (lastBlockInfo && lastBlockInfo.proposal) {
-      lastVotes.unshift(lastBlockInfo.proposal);
-    }
-
-    this.node.removeOldReceipts(blockNumber, tempDb);
-
-    for (const voteTx of lastVotes) {
-      if (CommonUtil.isFailedTx(tempDb.executeTransaction(Transaction.toExecutable(voteTx), true))) {
-        logger.debug(`[${LOG_HEADER}] failed to execute last vote: ${JSON.stringify(voteTx, null, 2)}`);
-        tempDb.destroyDb();
-        return null;
-      }
-    }
-
-    const transactions =
-        this.node.tp.getValidTransactions(longestNotarizedChain, tempDb.stateVersion);
-    const validTransactions = [];
+  getValidTransactions(longestNotarizedChain, blockNumber, blockTime, tempDb) {
+    const candidates = this.node.tp.getValidTransactions(longestNotarizedChain, tempDb.stateVersion);
+    const transactions = [];
     const invalidTransactions = [];
     const resList = [];
-    for (const tx of transactions) {
-      const res = tempDb.executeTransaction(Transaction.toExecutable(tx), false, true, blockNumber);
+    for (const tx of candidates) {
+      const res = tempDb.executeTransaction(Transaction.toExecutable(tx), false, true, blockNumber, blockTime);
       if (CommonUtil.txPrecheckFailed(res)) {
         logger.debug(`[${LOG_HEADER}] failed to execute transaction:\n${JSON.stringify(tx, null, 2)}\n${JSON.stringify(res, null, 2)})`);
         invalidTransactions.push(tx);
       } else {
-        validTransactions.push(tx);
+        transactions.push(tx);
         resList.push(res);
       }
     }
-    const { gasAmountTotal, gasCostTotal } =
-        CommonUtil.getServiceGasCostTotalFromTxList(validTransactions, resList);
-
     // Once successfully executed txs (when submitted to tx pool) can become invalid
     // after some blocks are created. Remove those transactions from tx pool.
     this.node.tp.removeInvalidTxsFromPool(invalidTransactions);
+    const { gasAmountTotal, gasCostTotal } =
+        CommonUtil.getServiceGasCostTotalFromTxList(transactions, resList);
+    return { transactions, gasAmountTotal, gasCostTotal };
+  }
 
-    const myAddr = this.node.account.address;
-    // Need the block#1 to be finalized to have the stakes reflected in the state
-    let validators = {};
-    if (this.node.bc.lastBlockNumber() < 1) {
-      const whitelist = GENESIS_WHITELIST;
-      for (const address in whitelist) {
-        if (whitelist[address] === true) {
-          const stake = tempDb.getValue(PathUtil.getConsensusStakingAccountBalancePath(address));
-          if (stake && MIN_STAKE_PER_VALIDATOR <= stake && stake <= MAX_STAKE_PER_VALIDATOR) {
-            validators[address] = {
-              [PredefinedDbPaths.STAKE]: stake,
-              [PredefinedDbPaths.PROPOSAL_RIGHT]: true
-            };
-          }
-        }
-      }
-      logger.debug(`[${LOG_HEADER}] validators: ${JSON.stringify(validators)}`);
-    } else {
-      validators = this.getValidators(lastBlock.hash, lastBlock.number);
-    }
-    const numValidators = Object.keys(validators).length;
-    if (!validators || !numValidators) {
-      tempDb.destroyDb();
-      throw Error('No whitelisted validators');
-    }
-    if (numValidators < MIN_NUM_VALIDATORS) {
-      tempDb.destroyDb();
-      throw Error(`Not enough validators: ${JSON.stringify(validators)}`);
-    }
-    const totalAtStake = Object.values(validators).reduce((acc, cur) => {
-      return acc + cur[PredefinedDbPaths.STAKE];
-    }, 0);
-    const stateProofHash = LIGHTWEIGHT ? '' : tempDb.getStateProof('/')[ProofProperties.PROOF_HASH];
-    const proposalBlock = Block.create(
-        lastBlock.hash, lastVotes, validTransactions, blockNumber, this.epoch,
-        stateProofHash, myAddr, validators, gasAmountTotal, gasCostTotal);
-
-    let proposalTx;
+  getProposalTx(blockNumber, validators, totalAtStake, gasCostTotal, offenses, proposalBlock) {
     const proposeOp = {
       type: WriteDbOperations.SET_VALUE,
       ref: PathUtil.getConsensusProposePath(blockNumber),
@@ -390,17 +353,18 @@ class Consensus {
         epoch: this.epoch,
         validators,
         total_at_stake: totalAtStake,
-        proposer: myAddr,
+        proposer: this.node.account.address,
         block_hash: proposalBlock.hash,
         last_hash: proposalBlock.last_hash,
         timestamp: proposalBlock.timestamp,
         gas_cost_total: gasCostTotal
       }
     }
-
+    if (!CommonUtil.isEmpty(offenses)) {
+      proposeOp.value.offenses = offenses;
+    }
     if (blockNumber <= ConsensusConsts.MAX_CONSENSUS_STATE_DB) {
-      proposalTx =
-          this.node.createTransaction({ operation: proposeOp, nonce: -1, gas_price: 1 });
+      return this.node.createTransaction({ operation: proposeOp, nonce: -1, gas_price: 1 });
     } else {
       const setOp = {
         type: WriteDbOperations.SET,
@@ -410,15 +374,65 @@ class Consensus {
             type: WriteDbOperations.SET_VALUE,
             ref: CommonUtil.formatPath([
               PredefinedDbPaths.CONSENSUS,
-              PredefinedDbPaths.NUMBER,
+              PredefinedDbPaths.CONSENSUS_NUMBER,
               blockNumber - ConsensusConsts.MAX_CONSENSUS_STATE_DB
             ]),
             value: null
           }
         ]
       };
-      proposalTx = this.node.createTransaction({ operation: setOp, nonce: -1, gas_price: 1 });
+      return this.node.createTransaction({ operation: setOp, nonce: -1, gas_price: 1 });
+    }
+  }
+
+  // proposing for block #N :
+  //    1. create a block (with last_votes)
+  //    2. create a tx (/consensus/number/N/propose: { block_hash, ... })
+  //    3. broadcast tx + block (i.e. call handleConsensusMessage())
+  //    4. verify block
+  //    5. execute propose tx
+  //    6. Nth propose tx should be included in the N+1th block's last_votes
+  createProposal(epoch) {
+    const LOG_HEADER = 'createProposal';
+    const { chain: longestNotarizedChain, recordedInvalidBlockHashSet } = this.getLongestNotarizedChain();
+    const lastBlock = longestNotarizedChain && longestNotarizedChain.length ?
+        longestNotarizedChain[longestNotarizedChain.length - 1] : this.node.bc.lastBlock();
+    const blockNumber = lastBlock.number + 1;
+    if (LIGHTWEIGHT && blockNumber > 1 && this.cache[blockNumber]) {
+      throw Error(`[${LOG_HEADER}] Already proposed ${blockNumber} / ${this.cache[blockNumber]}`);
     }
+    const baseVersion = lastBlock.number === this.node.bc.lastBlockNumber() ?
+        this.node.stateManager.getFinalVersion() :
+            this.blockPool.hashToDb.get(lastBlock.hash).stateVersion;
+    const tempDb = this.node.createTempDb(
+        baseVersion, `${StateVersions.CONSENSUS_CREATE}:${lastBlock.number}:${blockNumber}`,
+        lastBlock.number - 1);
+    if (!tempDb) {
+      throw Error(`[${LOG_HEADER}] Failed to create a temp database with state version: ${baseVersion}.`);
+    }
+    const blockTime = Date.now();
+    const lastVotes = this.blockPool.getValidLastVotes(lastBlock, blockNumber, blockTime, tempDb);
+    const validators = this.getValidators(lastBlock.hash, lastBlock.number, tempDb.stateVersion);
+    const numValidators = Object.keys(validators).length;
+    if (!validators || !numValidators) {
+      tempDb.destroyDb();
+      throw Error(`[${LOG_HEADER}] No whitelisted validators`);
+    }
+    if (numValidators < MIN_NUM_VALIDATORS) {
+      tempDb.destroyDb();
+      throw Error(`[${LOG_HEADER}] Not enough validators: ${JSON.stringify(validators)}`);
+    }
+    const totalAtStake = ConsensusUtil.getTotalAtStake(validators);
+    this.node.removeOldReceipts(blockNumber, tempDb);
+    const { offenses, evidence } = this.blockPool.getOffensesAndEvidence(
+        validators, recordedInvalidBlockHashSet, blockTime, tempDb);
+    const { transactions, gasAmountTotal, gasCostTotal } = this.getValidTransactions(
+        longestNotarizedChain, blockNumber, blockTime, tempDb);
+    const stateProofHash = LIGHTWEIGHT ? '' : tempDb.getStateProof('/')[ProofProperties.PROOF_HASH];
+    const proposalBlock = Block.create(
+        lastBlock.hash, lastVotes, evidence, transactions, blockNumber, epoch,
+        stateProofHash, this.node.account.address, validators, gasAmountTotal, gasCostTotal, blockTime);
+    const proposalTx = this.getProposalTx(blockNumber, validators, totalAtStake, gasCostTotal, offenses, proposalBlock);
     if (LIGHTWEIGHT) {
       this.cache[blockNumber] = proposalBlock.hash;
     }
@@ -426,250 +440,383 @@ class Consensus {
     return { proposalBlock, proposalTx: Transaction.toJsObject(proposalTx) };
   }
 
-  checkProposal(proposalBlock, proposalTx) {
-    const LOG_HEADER = 'checkProposal';
-    const block = Block.parse(proposalBlock);
-    if (!block) {
-      logger.error(`[${LOG_HEADER}] Invalid block: ${JSON.stringify(proposalBlock)}`);
-      return false;
-    }
-    const { proposer, number, epoch, hash, last_hash, validators, last_votes, transactions,
-        gas_amount_total, gas_cost_total, state_proof_hash } = block;
-
-    logger.info(`[${LOG_HEADER}] Checking block proposal: ${number} / ${epoch}`);
-    if (this.blockPool.hasSeenBlock(proposalBlock)) {
-      logger.info(`[${LOG_HEADER}] Proposal already seen`);
-      return false;
+  precheckProposal(proposalBlock, proposalTx, proposer, hash, number, validators) {
+    if (this.blockPool.hasSeenBlock(hash)) {
+      throw new ConsensusError({
+        code: ConsensusErrorCode.RECEIVED_PROPOSAL,
+        message: `Already have seen this proposal`,
+        level: 'info'
+      });
     }
     if (proposalTx.address !== proposer) {
-      logger.error(`[${LOG_HEADER}] Transaction signer and proposer are different`);
-      return false;
+      throw new ConsensusError({
+        code: ConsensusErrorCode.PROPOSER_MISMATCH,
+        message: `Transaction signer and proposer are different`,
+        level: 'error'
+      });
+    }
+    const blockHashFromTx = ConsensusUtil.getBlockHashFromConsensusTx(proposalTx);
+    if (blockHashFromTx !== hash) {
+      throw new ConsensusError({
+        code: ConsensusErrorCode.BLOCK_HASH_MISMATCH,
+        message: `The block_hash value in proposalTx (${blockHashFromTx}) and ` +
+            `the actual proposalBlock's hash (${hash}) don't match`,
+        level: 'error'
+      });
     }
-    const blockHash = BlockPool.getBlockHashFromTx(proposalTx);
-    if (blockHash !== hash) {
-      logger.error(`[${LOG_HEADER}] The block_hash value in proposalTx (${blockHash}) and ` +
-          `the actual proposalBlock's hash (${hash}) don't match`);
-      return false;
+    // Make sure we have validators within MIN_NUM_VALIDATORS and MAX_NUM_VALIDATORS.
+    if (Object.keys(validators).length < MIN_NUM_VALIDATORS || Object.keys(validators).length > MAX_NUM_VALIDATORS) {
+      throw new ConsensusError({
+        code: ConsensusErrorCode.INVALID_VALIDATORS_SIZE,
+        message: `Invalid validator set size (${JSON.stringify(validators)})\n` +
+            `MIN_NUM_VALIDATORS: ${MIN_NUM_VALIDATORS}, MAX_NUM_VALIDATORS: ${MAX_NUM_VALIDATORS}`,
+        level: 'error'
+      });
     }
     if (!LIGHTWEIGHT) {
       if (!Block.validateProposedBlock(proposalBlock)) {
-        logger.error(`[${LOG_HEADER}] Proposed block didn't pass the basic checks`);
-        return false;
-      }
-    }
-    if (number <= this.node.bc.lastBlockNumber()) {
-      logger.info(`[${LOG_HEADER}] There already is a finalized block of the number`);
-      logger.debug(`[${LOG_HEADER}] corresponding block info: ` +
-          `${JSON.stringify(this.blockPool.hashToBlockInfo[hash], null, 2)}`);
-      if (!this.blockPool.hasSeenBlock(proposalBlock)) {
-        logger.debug(`[${LOG_HEADER}] Adding the proposal to the blockPool for later use`);
-        this.blockPool.addSeenBlock(proposalBlock, proposalTx);
+        throw new ConsensusError({
+          code: ConsensusErrorCode.ILL_FORMED_BLOCK,
+          message: `Proposed block didn't pass the basic checks`,
+          level: 'error'
+        });
       }
-      return false;
-    }
-    // If I don't have enough votes for prevBlock, see last_votes of proposalBlock if
-    // those can notarize the prevBlock (verify, execute and add the missing votes)
-    let prevBlockInfo = number === 1 ?
-        this.node.bc.getBlockByNumber(0) : this.blockPool.hashToBlockInfo[last_hash];
-    logger.debug(`[${LOG_HEADER}] prevBlockInfo: ${JSON.stringify(prevBlockInfo, null, 2)}`);
-    if (number !== 1 && (!prevBlockInfo || !prevBlockInfo.block)) {
-      logger.debug(`[${LOG_HEADER}] No notarized block at number ${number - 1} with ` +
-          `hash ${last_hash}`);
-      return;
-    }
-    const prevBlock = number > 1 ? prevBlockInfo.block : prevBlockInfo;
-
-    // Make sure we have validators within MIN_NUM_VALIDATORS and MAX_NUM_VALIDATORS.
-    if (Object.keys(validators).length < MIN_NUM_VALIDATORS || Object.keys(validators).length > MAX_NUM_VALIDATORS) {
-      logger.error(
-          `[${LOG_HEADER}] Invalid validator set size (${JSON.stringify(validators)})\n` +
-          `MIN_NUM_VALIDATORS: ${MIN_NUM_VALIDATORS}, MAX_NUM_VALIDATORS: ${MAX_NUM_VALIDATORS}`);
-      return false;
     }
+  }
 
-    if (number !== 1 && !prevBlockInfo.notarized) {
-      // Try applying the last_votes of proposalBlock and see if that makes the prev block notarized
-      const prevBlockProposal = BlockPool.filterProposal(last_votes);
-      if (!prevBlockProposal) {
-        logger.error(`[${LOG_HEADER}] Proposal block is missing its prev block's proposal ` +
-            'in last_votes');
-        return false;
-      }
-      if (!prevBlockInfo.proposal) {
-        if (number === this.node.bc.lastBlockNumber() + 1) {
-          // TODO(liayoo): Do more checks on the prevBlockProposal.
-          this.blockPool.addSeenBlock(prevBlockInfo.block, prevBlockProposal);
-        } else {
-          logger.debug(`[${LOG_HEADER}] Prev block is missing its proposal`);
-          return false;
-        }
-      }
-      let baseVersion;
-      let prevDb;
-      let isSnapDb = false;
-      if (prevBlock.number === this.node.bc.lastBlockNumber()) {
-        baseVersion = this.node.stateManager.getFinalVersion();
-      } else if (this.blockPool.hashToDb.has(last_hash)) {
-        baseVersion = this.blockPool.hashToDb.get(last_hash).stateVersion;
-      } else {
-        prevDb = this.getSnapDb(prevBlock);
-        isSnapDb = true;
-        if (!prevDb) {
-          logger.error(`[${LOG_HEADER}] Previous db state doesn't exist`);
-          return false;
-        }
-        baseVersion = prevDb.stateVersion;
-      }
-      const tempDb = this.node.createTempDb(
-          baseVersion, `${StateVersions.CONSENSUS_VOTE}:${prevBlock.number}:${number}`,
-          prevBlock.number - 1);
-      if (!tempDb) {
-        logger.error(`Failed to create a temp database with state version: ${baseVersion}.`);
-        return null;
-      }
-      if (isSnapDb) {
-        prevDb.destroyDb();
-      }
-      for (const voteTx of last_votes) {
-        if (voteTx.hash === prevBlockProposal.hash) continue;
-        if (!Consensus.isValidConsensusTx(voteTx) ||
-            CommonUtil.isFailedTx(
-                tempDb.executeTransaction(Transaction.toExecutable(voteTx), true))) {
-          logger.error(`[${LOG_HEADER}] voting tx execution for prev block failed`);
-          tempDb.destroyDb();
-          return false;
-        } else {
-          this.blockPool.addSeenVote(voteTx);
-        }
-      }
-      tempDb.destroyDb();
-      prevBlockInfo = this.blockPool.hashToBlockInfo[last_hash];
-      if (!prevBlockInfo.notarized) {
-        logger.error(`[${LOG_HEADER}] Block's last_votes don't correctly notarize ` +
-            `its previous block of number ${number - 1} with hash ` +
-            `${last_hash}:\n${JSON.stringify(this.blockPool.hashToBlockInfo[last_hash], null, 2)}`);
-        return false;
-      }
+  getPrevBlockInfo(number, lastHash) {
+    const prevBlockInfo = number === 1 ?
+        { block: this.node.bc.getBlockByNumber(0) } : this.blockPool.hashToBlockInfo[lastHash];
+    if (number !== 1 && (!prevBlockInfo || !prevBlockInfo.block)) {
+      throw new ConsensusError({
+        code: ConsensusErrorCode.INVALID_PREV_BLOCK,
+        message: `No notarized block at number ${number - 1} with hash ${lastHash}`,
+        level: 'error'
+      });
     }
+    return prevBlockInfo;
+  }
 
-    if (prevBlock.epoch >= epoch) {
-      logger.error(`[${LOG_HEADER}] Previous block's epoch (${prevBlock.epoch}) ` +
-          `is greater than or equal to incoming block's (${epoch})`);
-      return false;
-    }
-    const seed = '' + prevBlock.last_votes_hash + epoch;
-    const expectedProposer = Consensus.selectProposer(seed, validators);
-    if (expectedProposer !== proposer) {
-      logger.error(`[${LOG_HEADER}] Proposer is not the expected node (expected: ` +
-          `${expectedProposer} / actual: ${proposer})`);
-      return false;
-    }
-    // TODO(liayoo): Check last_votes if they indeed voted for the previous block.
+  getBaseVersionAndPrevDb(prevBlock, lastHash) {
     let baseVersion;
     let prevDb;
     let isSnapDb = false;
     if (prevBlock.number === this.node.bc.lastBlockNumber()) {
       baseVersion = this.node.stateManager.getFinalVersion();
-    } else if (this.blockPool.hashToDb.has(last_hash)) {
-      baseVersion = this.blockPool.hashToDb.get(last_hash).stateVersion;
+    } else if (this.blockPool.hashToDb.has(lastHash)) {
+      baseVersion = this.blockPool.hashToDb.get(lastHash).stateVersion;
     } else {
       prevDb = this.getSnapDb(prevBlock);
       if (!prevDb) {
-        logger.error(`[${LOG_HEADER}] Previous db state doesn't exist`);
-        return false;
+        throw new ConsensusError({
+          code: ConsensusErrorCode.MISSING_DB_FOR_PREV_BLOCK,
+          message: `Previous db state doesn't exist`,
+          level: 'error'
+        });
       }
       isSnapDb = true;
       baseVersion = prevDb.stateVersion;
     }
+    return { baseVersion, prevDb, isSnapDb };
+  }
+
+  validatePrevBlock(prevBlockInfo, number, epoch, lastVotes) {
+    const prevBlock = prevBlockInfo.block;
+    if (prevBlock.epoch >= epoch) {
+      throw new ConsensusError({
+        code: ConsensusErrorCode.INVALID_EPOCH,
+        message: `Previous block's epoch (${prevBlock.epoch}) ` +
+            `is greater than or equal to incoming block's (${epoch})`,
+        level: 'error'
+      });
+    }
+    if (prevBlockInfo.notarized || number === 1) {
+      return;
+    }
+    // Try applying the last_votes of proposalBlock and see if that makes the prevBlock notarized.
+    const prevBlockProposal = ConsensusUtil.filterProposalFromVotes(lastVotes);
+    if (!prevBlockProposal) {
+      throw new ConsensusError({
+        code: ConsensusErrorCode.MISSING_PROPOSAL_IN_LAST_VOTES,
+        message: `Proposal block is missing its prev block's proposal in last_votes`,
+        level: 'error'
+      });
+    }
+    if (!prevBlockInfo.proposal) {
+      if (number === this.node.bc.lastBlockNumber() + 1) {
+        // TODO(liayoo): Do more checks on the prevBlockProposal.
+        this.blockPool.addSeenBlock(prevBlockInfo.block, prevBlockProposal);
+      } else {
+        throw new ConsensusError({
+          code: ConsensusErrorCode.MISSING_PROPOSAL_IN_BLOCK_POOL,
+          message: `Prev block is missing its proposal`,
+          level: 'debug'
+        });
+      }
+    }
+  }
+
+  validateProposer(prevBlockLastVotesHash, epoch, validators, proposer) {
+    const seed = '' + prevBlockLastVotesHash + epoch;
+    const expectedProposer = Consensus.selectProposer(seed, validators);
+    if (expectedProposer !== proposer) {
+      throw new ConsensusError({
+        code: ConsensusErrorCode.INVALID_PROPOSER,
+        message: `Proposer is not the expected node (expected: ${expectedProposer} / actual: ${proposer})`,
+        level: 'error'
+      });
+    }
+  }
+
+  getNewDbForProposal(prevBlock, number, baseVersion, prevDb, isSnapDb) {
     const newDb = this.node.createTempDb(
         baseVersion, `${StateVersions.POOL}:${prevBlock.number}:${number}`, prevBlock.number);
     if (!newDb) {
-      logger.error(`Failed to create a temp database with state version: ${baseVersion}.`);
-      return null;
+      throw new ConsensusError({
+        code: ConsensusErrorCode.TEMP_DB_CREATION_FAILURE,
+        message: `Failed to create a temp database with state version: ${baseVersion}.`,
+        level: 'error'
+      });
     }
     if (isSnapDb) {
       prevDb.destroyDb();
     }
+    return newDb;
+  }
 
-    this.node.removeOldReceipts(number, newDb);
-    if (!newDb.executeTransactionList(last_votes, true)) {
-      logger.error(`[${LOG_HEADER}] Failed to execute last votes`);
+  validateLastVotesAndExecuteOnNewDb(lastVotes, lastHash, number, blockTime, newDb) {
+    if (!newDb.executeTransactionList(lastVotes, true, false, 0, blockTime)) {
       newDb.destroyDb();
-      return false;
+      throw new ConsensusError({
+        code: ConsensusErrorCode.EXECUTING_LAST_VOTES_FAILURE,
+        message: `Failed to execute last votes`,
+        level: 'error'
+      });
+    }
+    for (const vote of lastVotes) {
+      this.blockPool.addSeenVote(vote);
+    }
+    if (!this.blockPool.hashToBlockInfo[lastHash].notarized) {
+      throw new ConsensusError({
+        code: ConsensusErrorCode.INVALID_LAST_VOTES_STAKES,
+        message: `Block's last_votes don't correctly notarize its previous block of number ` +
+            `${number - 1} with hash ${lastHash}:\n` +
+            `${JSON.stringify(this.blockPool.hashToBlockInfo[lastHash], null, 2)}`,
+        level: 'error'
+      });
     }
-    const txsRes = newDb.executeTransactionList(transactions, false, true, number);
+  }
+
+  // Cross-check the offenses in proposalTx & the evidence in proposalBlock
+  validateOffensesAndEvidence(proposalBlock, proposalTx, validators, prevBlockMajority, blockTime, newDb) {
+    const offenses = ConsensusUtil.getOffensesFromProposalTx(proposalTx);
+    const evidence = proposalBlock.evidence;
+    if (CommonUtil.isEmpty(offenses) !== CommonUtil.isEmpty(evidence)) {
+      newDb.destroyDb();
+      throw new ConsensusError({
+        code: ConsensusErrorCode.OFFENSES_EVIDENCE_MISMATCH,
+        message: `Offenses and evidence don't match: ` +
+            `${JSON.stringify(offenses)} / ${JSON.stringify(evidence)}`,
+        level: 'error'
+      });
+    }
+    if (CommonUtil.isEmpty(evidence)) {
+      return;
+    }
+    for (const [offender, evidenceList] of Object.entries(evidence)) {
+      const tempOffenses = {};
+      for (const evidenceForOffense of evidenceList) {
+        if (!CommonUtil.isValidatorOffenseType(evidenceForOffense.offense_type)) {
+          newDb.destroyDb();
+          throw new ConsensusError({
+            code: ConsensusErrorCode.INVALID_OFFENSE_TYPE,
+            message: ``,
+            level: 'error'
+          });
+        }
+        const tallied = evidenceForOffense.votes.reduce((acc, vote) => {
+          return acc + _.get(validators, `${vote.address}.stake`, 0);
+        }, 0);
+        if (tallied < prevBlockMajority) {
+          newDb.destroyDb();
+          throw new ConsensusError({
+            code: ConsensusErrorCode.INVALID_EVIDENCE_VOTES_STAKES,
+            message: `Evidence votes don't meet the majority`,
+            level: 'error'
+          });
+        }
+        const txsRes = newDb.executeTransactionList(evidenceForOffense.votes, true, false, 0, blockTime);
+        if (!txsRes) {
+          newDb.destroyDb();
+          throw new ConsensusError({
+            code: ConsensusErrorCode.EXECUTING_EVIDENCE_VOTES_FAILURE,
+            message: `Failed to execute evidence votes`,
+            level: 'error'
+          });
+        }
+        if (!tempOffenses[evidenceForOffense.offense_type]) {
+          tempOffenses[evidenceForOffense.offense_type] = 0;
+        }
+        tempOffenses[evidenceForOffense.offense_type] += 1;
+      }
+      if (!_.isEqual(offenses[offender], tempOffenses, { strict: true })) {
+        newDb.destroyDb();
+        throw new ConsensusError({
+          code: ConsensusErrorCode.INVALID_OFFENSE_COUNTS,
+          message: `Invalid offense counts`,
+          level: 'error'
+        });
+      }
+    }
+  }
+
+  validateTransactions(transactions, number, blockTime, expectedGasAmountTotal, expectedGasCostTotal, newDb) {
+    const txsRes = newDb.executeTransactionList(transactions, false, true, number, blockTime);
     if (!txsRes) {
-      logger.error(`[${LOG_HEADER}] Failed to execute transactions`);
       newDb.destroyDb();
-      return false;
+      throw new ConsensusError({
+        code: ConsensusErrorCode.EXECUTING_TX_FAILURE,
+        message: `Failed to execute transactions`,
+        level: 'error'
+      });
     }
     const { gasAmountTotal, gasCostTotal } =
         CommonUtil.getServiceGasCostTotalFromTxList(transactions, txsRes);
-    if (gasAmountTotal !== gas_amount_total) {
-      logger.error(`[${LOG_HEADER}] Invalid gas_amount_total`);
+    if (gasAmountTotal !== expectedGasAmountTotal) {
       newDb.destroyDb();
-      return false;
+      throw new ConsensusError({
+        code: ConsensusErrorCode.INVALID_GAS_AMOUNT_TOTAL,
+        message: `Invalid gas_amount_total`,
+        level: 'error'
+      });
     }
-    if (gasCostTotal !== gas_cost_total) {
-      logger.error(`[${LOG_HEADER}] Invalid gas_cost_total`);
+    if (gasCostTotal !== expectedGasCostTotal) {
       newDb.destroyDb();
-      return false;
+      throw new ConsensusError({
+        code: ConsensusErrorCode.INVALID_GAS_COST_TOTAL,
+        message: `Invalid gas_cost_total`,
+        level: 'error'
+      });
     }
+  }
 
-    // Try executing the proposal tx on the proposal block's db state
+  validateProposalTx(proposalTx, number, blockTime, newDb) {
     const executableTx = Transaction.toExecutable(proposalTx);
     if (!executableTx) {
-      logger.error(`[${LOG_HEADER}] Failed to create a transaction with a proposal: ` +
-          `${JSON.stringify(proposalTx, null, 2)}`);
       newDb.destroyDb();
-      return false;
+      throw new ConsensusError({
+        code: ConsensusErrorCode.ILL_FORMED_PROPOSAL_TX,
+        message: `Failed to create a transaction with a proposal: ${JSON.stringify(proposalTx, null, 2)}`,
+        level: 'error'
+      });
     }
     const tempDb = this.node.createTempDb(
-        newDb.stateVersion, `${StateVersions.CONSENSUS_PROPOSE}:${prevBlock.number}:${number}`,
-        prevBlock.number - 1);
+        newDb.stateVersion, `${StateVersions.CONSENSUS_PROPOSE}:${number - 1}:${number}`,
+        number - 2);
     if (!tempDb) {
-      logger.error(`Failed to create a temp database with state version: ${newDb.stateVersion}.`);
       newDb.destroyDb();
-      return null;
+      throw new ConsensusError({
+        code: ConsensusErrorCode.TEMP_DB_CREATION_FAILURE,
+        message: `Failed to create a temp database with state version: ${newDb.stateVersion}`,
+        level: 'error'
+      });
     }
-    const proposalTxExecRes = tempDb.executeTransaction(executableTx, true);
+    // Try executing the proposal tx on the proposal block's db state
+    const proposalTxExecRes = tempDb.executeTransaction(executableTx, true, false, 0, blockTime);
     if (CommonUtil.isFailedTx(proposalTxExecRes)) {
-      logger.error(
-          `[${LOG_HEADER}] Failed to execute the proposal tx: ` +
-          `${JSON.stringify(proposalTxExecRes)}`);
       newDb.destroyDb();
       tempDb.destroyDb();
-      return false;
+      throw new ConsensusError({
+        code: ConsensusErrorCode.EXECUTING_PROPOSAL_FAILURE,
+        message: `Failed to execute the proposal tx: ${JSON.stringify(proposalTxExecRes)}`,
+        level: 'error'
+      });
     }
     tempDb.destroyDb();
     this.node.tp.addTransaction(executableTx);
     newDb.blockNumberSnapshot += 1;
-    if (!LIGHTWEIGHT) {
-      if (newDb.getStateProof('/')[ProofProperties.PROOF_HASH] !== state_proof_hash) {
-        logger.error(`[${LOG_HEADER}] State proof hashes don't match: ` +
-            `${newDb.getStateProof('/')[ProofProperties.PROOF_HASH]} / ` +
-            `${state_proof_hash}\n\n${JSON.stringify(proposalBlock, null, 2)}`);
-        return false;
-      }
+  }
+
+  validateStateProofHash(expectedStateProofHash, newDb) {
+    if (LIGHTWEIGHT) {
+      return;
+    }
+    const stateProofHash = newDb.getStateProof('/')[ProofProperties.PROOF_HASH];
+    if (stateProofHash !== expectedStateProofHash) {
+      newDb.destroyDb();
+      throw new ConsensusError({
+        code: ConsensusErrorCode.INVALID_STATE_PROOF_HASH,
+        message: `State proof hashes don't match: ${stateProofHash} / ${expectedStateProofHash}`,
+        level: 'error'
+      });
+    }
+  }
+
+  /**
+   * Performs various checks on the proposalBlock and proposalTx. Throws ConsensusError if a check
+   * fails. If the ConsensusError's code is one of the `ConsensusErrorCodesToVoteAgainst`,
+   * the node will try to vote against the block.
+   * @param {Block} proposalBlock
+   * @param {Transaction} proposalTx
+   */
+  checkProposal(proposalBlock, proposalTx) {
+    const LOG_HEADER = 'checkProposal';
+    const block = Block.parse(proposalBlock);
+    if (!block) {
+      throw new ConsensusError({
+        code: ConsensusErrorCode.PARSING_PROPOSAL_BLOCK_FAILURE,
+        message: `Unable to parse block: ${JSON.stringify(proposalBlock)}`,
+        level: 'error'
+      });
     }
+    const { proposer, number, epoch, hash, last_hash, validators, last_votes, transactions,
+        gas_amount_total, gas_cost_total, state_proof_hash, timestamp } = block;
+    logger.info(`[${LOG_HEADER}] Checking block proposal: ${number} / ${epoch}`);
+    this.precheckProposal(block, proposalTx, proposer, hash, number, validators);
+
+    const prevBlockInfo = this.getPrevBlockInfo(number, last_hash);
+    const prevBlock = prevBlockInfo.block;
+    this.validatePrevBlock(prevBlockInfo, number, epoch, last_votes);
+    this.validateProposer(prevBlock.last_votes_hash, epoch, validators, proposer);
+
+    const { baseVersion, prevDb, isSnapDb } = this.getBaseVersionAndPrevDb(prevBlock, last_hash);
+    const newDb = this.getNewDbForProposal(prevBlock, number, baseVersion, prevDb, isSnapDb);
+    const prevBlockTotalAtStake = ConsensusUtil.getTotalAtStake(prevBlock.validators);
+    const prevBlockMajority = prevBlockTotalAtStake * ConsensusConsts.MAJORITY;
+    this.node.removeOldReceipts(number, newDb);
+    this.validateLastVotesAndExecuteOnNewDb(last_votes, last_hash, number, timestamp, newDb);
+    this.validateOffensesAndEvidence(block, proposalTx, validators, prevBlockMajority, timestamp, newDb);
+    this.validateTransactions(transactions, number, timestamp, gas_amount_total, gas_cost_total, newDb);
+    this.validateProposalTx(proposalTx, number, timestamp, newDb);
+    this.validateStateProofHash(state_proof_hash, newDb);
+
     if (!this.blockPool.addSeenBlock(proposalBlock, proposalTx)) {
       newDb.destroyDb();
-      return false;
+      throw new ConsensusError({
+        code: ConsensusErrorCode.ADDING_TO_BLOCK_POOL_FAILURE,
+        message: `Unable to add block to block pool: ${JSON.stringify(proposalBlock)}`,
+        level: 'error'
+      });
     }
     this.blockPool.hashToDb.set(hash, newDb);
+
     if (!this.blockPool.longestNotarizedChainTips.includes(last_hash)) {
-      logger.info(`[${LOG_HEADER}] Block is not extending one of the longest notarized chains ` +
-          `(${JSON.stringify(this.blockPool.longestNotarizedChainTips, null, 2)})`);
-      return false;
+      throw new ConsensusError({
+        code: ConsensusErrorCode.NOT_EXTENDING_LNC_ERROR,
+        message: `Block is not extending one of the longest notarized chains ` +
+            `(${JSON.stringify(this.blockPool.longestNotarizedChainTips, null, 2)})`,
+        level: 'info'
+      });
     }
     logger.info(`[${LOG_HEADER}] Verifed block proposal: ${number} / ${epoch}`);
-    return true;
   }
 
   checkVoteTx(voteTx) {
     const LOG_HEADER = 'checkVoteTx';
-    const blockHash = voteTx.tx_body.operation.value.block_hash;
-    const blockInfo = this.blockPool.hashToBlockInfo[blockHash];
+    const blockHash = ConsensusUtil.getBlockHashFromConsensusTx(voteTx);
+    const isAgainst = ConsensusUtil.isAgainstVoteTx(voteTx);
+    const blockInfo = this.blockPool.hashToBlockInfo[blockHash] ||
+        this.blockPool.hashToInvalidBlockInfo[blockHash];
     let block;
     if (blockInfo && blockInfo.block) {
       block = blockInfo.block;
@@ -677,64 +824,74 @@ class Consensus {
       block = this.node.bc.lastBlock();
     }
     if (!block) {
-      logger.error(`[${LOG_HEADER}] Cannot verify the vote without the block it's voting for: ` +
+      logger.debug(`[${LOG_HEADER}] Cannot verify the vote without the block it's voting for: ` +
           `${blockHash} / ${JSON.stringify(blockInfo, null, 2)}`);
       // FIXME: ask for the block from peers
       return false;
     }
     const executableTx = Transaction.toExecutable(voteTx);
     if (!executableTx) {
-      logger.error(`[${LOG_HEADER}] Failed to create a transaction with a vote: ` +
-          `${JSON.stringify(voteTx, null, 2)}`);
+      logger.error(`[${LOG_HEADER}] Ill-formed vote tx: ${JSON.stringify(voteTx, null, 2)}`);
       return false;
     }
-    const tempDb = this.getSnapDb(block);
+    let tempDb;
+    if (isAgainst) {
+      const offenseType = ConsensusUtil.getOffenseTypeFromVoteTx(voteTx);
+      if (!CommonUtil.isValidatorOffenseType(offenseType)) {
+        logger.debug(`[${LOG_HEADER}] Invalid offense type: ${offenseType}`);
+        return false;
+      }
+      const lastBlock = this.node.bc.lastBlock();
+      tempDb = this.node.createTempDb(
+          this.node.stateManager.getFinalVersion(),
+          `${StateVersions.SNAP}:${lastBlock.number}`, lastBlock.number);
+    } else {
+      tempDb = this.getSnapDb(block);
+    }
     if (!tempDb) {
       logger.debug(
           `[${LOG_HEADER}] No state snapshot available for vote ${JSON.stringify(executableTx)}`);
       return false;
     }
-    const voteTxRes = tempDb.executeTransaction(executableTx, true);
+    const voteTxRes = tempDb.executeTransaction(executableTx, true, false, 0, block.timestamp);
     tempDb.destroyDb();
     if (CommonUtil.isFailedTx(voteTxRes)) {
       logger.error(`[${LOG_HEADER}] Failed to execute the voting tx: ${JSON.stringify(voteTxRes)}`);
       return false;
     }
     this.node.tp.addTransaction(executableTx);
-    this.blockPool.addSeenVote(voteTx, this.epoch);
+    this.blockPool.addSeenVote(voteTx);
     return true;
   }
 
   tryPropose() {
     const LOG_HEADER = 'tryPropose';
 
-    if (this.votedForEpoch(this.epoch)) {
+    const epoch = this.epoch;
+    if (this.votedForEpoch(epoch)) {
       logger.info(
-          `[${LOG_HEADER}] Already voted for ${this.blockPool.epochToBlock[this.epoch]} ` +
-          `at epoch ${this.epoch} but trying to propose at the same epoch`);
+          `[${LOG_HEADER}] Already voted for ${this.blockPool.epochToBlock[epoch]} ` +
+          `at epoch ${epoch} but trying to propose at the same epoch`);
       return;
     }
     if (this.proposer && CommonUtil.areSameAddrs(this.proposer, this.node.account.address)) {
       logger.info(`[${LOG_HEADER}] I'm the proposer ${this.node.account.address}`);
       try {
-        const proposal = this.createProposal();
-        if (proposal !== null) {
-          const consensusMsg = this.encapsulateConsensusMessage(
-              proposal, ConsensusMessageTypes.PROPOSE);
-          this.handleConsensusMessage(consensusMsg);
-        }
+        const consensusMsg = this.encapsulateConsensusMessage(
+            this.createProposal(epoch), ConsensusMessageTypes.PROPOSE);
+        this.handleConsensusMessage(consensusMsg);
       } catch (err) {
-        logger.error(`[${LOG_HEADER}] Error while creating a proposal: ${err} ${err.stack}`);
+        logger.error(`[${LOG_HEADER}] Error while creating a proposal: ${err.stack}`);
       }
     } else {
       logger.info(`[${LOG_HEADER}] Not my turn ${this.node.account.address}`);
     }
   }
 
-  tryVote(proposalBlock) {
-    const LOG_HEADER = 'tryVote';
+  tryVoteForValidBlock(proposalBlock) {
+    const LOG_HEADER = 'tryVoteForValidBlock';
     logger.info(`[${LOG_HEADER}] Trying to vote for ${proposalBlock.number} / ` +
-        `${proposalBlock.epoch} / ${proposalBlock.hash}`)
+        `${proposalBlock.epoch} / ${proposalBlock.hash}`);
     if (this.votedForEpoch(proposalBlock.epoch)) {
       logger.info(`[${LOG_HEADER}] Already voted for epoch ${proposalBlock.epoch}`);
       return;
@@ -742,23 +899,51 @@ class Consensus {
     if (proposalBlock.epoch < this.epoch) {
       logger.info(
           `[${LOG_HEADER}] Possibly a stale proposal (${proposalBlock.epoch} / ${this.epoch})`);
-      // FIXME
     }
-    this.vote(proposalBlock);
+    const myAddr = this.node.account.address;
+    const validatorInfo = proposalBlock.validators[myAddr];
+    if (!validatorInfo) {
+      return;
+    }
+    const operation = {
+      type: WriteDbOperations.SET_VALUE,
+      ref: PathUtil.getConsensusVotePath(proposalBlock.number, proposalBlock.hash, myAddr),
+      value: {
+        [PredefinedDbPaths.CONSENSUS_BLOCK_HASH]: proposalBlock.hash,
+        [PredefinedDbPaths.CONSENSUS_STAKE]: validatorInfo.stake,
+        [PredefinedDbPaths.CONSENSUS_IS_AGAINST]: false,
+      }
+    };
+    const voteTx = this.node.createTransaction({ operation, nonce: -1, gas_price: 1 });
+    const consensusMsg = this.encapsulateConsensusMessage(
+        Transaction.toJsObject(voteTx), ConsensusMessageTypes.VOTE);
+    this.handleConsensusMessage(consensusMsg);
   }
 
-  vote(block) {
+  tryVoteAgainstInvalidBlock(proposalBlock, proposalTx) {
+    const LOG_HEADER = 'tryVoteAgainstInvalidBlock';
+    logger.info(`[${LOG_HEADER}] Trying to vote against ${proposalBlock.number} / ` +
+        `${proposalBlock.epoch} / ${proposalBlock.hash}`);
+    if (this.votedForBlock(proposalBlock.hash)) {
+      logger.info(`[${LOG_HEADER}] Already voted against block ${proposalBlock.hash}`);
+      return;
+    }
     const myAddr = this.node.account.address;
-    const isValidator = block.validators[myAddr];
-    if (!isValidator) {
+    // NOTE(liayoo): Try voting if I was one of the validators in the last notarized block. However,
+    //               only the votes from the validators in next block's previous block will be counted.
+    const lastNotarizedBlock = this.getLastNotarizedBlock();
+    const validatorInfo = lastNotarizedBlock.validators[myAddr];
+    if (!validatorInfo) {
       return;
     }
     const operation = {
       type: WriteDbOperations.SET_VALUE,
-      ref: PathUtil.getConsensusVotePath(block.number, myAddr),
+      ref: PathUtil.getConsensusVotePath(proposalBlock.number, proposalBlock.hash, myAddr),
       value: {
-        [PredefinedDbPaths.BLOCK_HASH]: block.hash,
-        [PredefinedDbPaths.STAKE]: isValidator.stake
+        [PredefinedDbPaths.CONSENSUS_BLOCK_HASH]: proposalBlock.hash,
+        [PredefinedDbPaths.CONSENSUS_STAKE]: validatorInfo.stake,
+        [PredefinedDbPaths.CONSENSUS_IS_AGAINST]: true,
+        [PredefinedDbPaths.CONSENSUS_OFFENSE_TYPE]: ValidatorOffenseTypes.INVALID_PROPOSAL,
       }
     };
     const voteTx = this.node.createTransaction({ operation, nonce: -1, gas_price: 1 });
@@ -778,6 +963,7 @@ class Consensus {
       return;
     }
     // Discard the last block (but save it for a future finalization)
+    const recordedInvalidBlocks = new Set();
     for (let i = 0; i < finalizableChain.length - 1; i++) {
       const blockToFinalize = finalizableChain[i];
       if (blockToFinalize.number <= this.node.bc.lastBlockNumber()) {
@@ -788,6 +974,15 @@ class Consensus {
             `hash ${blockToFinalize.hash}`);
         const versionToFinalize = this.blockPool.hashToDb.get(blockToFinalize.hash).stateVersion;
         this.node.cloneAndFinalizeVersion(versionToFinalize, blockToFinalize.number);
+        if (!CommonUtil.isEmpty(blockToFinalize.evidence)) {
+          Object.values(blockToFinalize.evidence).forEach((evidenceList) => {
+            evidenceList.forEach((val) => {
+              if (val.offense_type === ValidatorOffenseTypes.INVALID_PROPOSAL) {
+                recordedInvalidBlocks.add(val.block.hash);
+              }
+            });
+          });
+        }
       } else {
         logger.error(`[${LOG_HEADER}] Failed to finalize a block: ` +
             `${JSON.stringify(blockToFinalize, null, 2)}`);
@@ -795,7 +990,8 @@ class Consensus {
         return;
       }
     }
-    this.blockPool.cleanUpAfterFinalization(finalizableChain[finalizableChain.length - 2]);
+    this.blockPool.cleanUpAfterFinalization(
+        finalizableChain[finalizableChain.length - 2], recordedInvalidBlocks);
     this.reportStateProofHashes();
   }
 
@@ -803,41 +999,52 @@ class Consensus {
     const LOG_HEADER = 'catchUp';
     if (!blockList || !blockList.length) return;
     let lastVerifiedBlock;
-    blockList.forEach((blockInfo) => {
+    for (const blockInfo of blockList) {
       logger.debug(`[${LOG_HEADER}] Adding notarized chain's block: ` +
           `${JSON.stringify(blockInfo, null, 2)}`);
       const lastNotarizedBlock = this.getLastNotarizedBlock();
       logger.info(`[${LOG_HEADER}] Current lastNotarizedBlock: ` +
           `${lastNotarizedBlock.number} / ${lastNotarizedBlock.epoch}`);
-      if (!blockInfo.block || !blockInfo.proposal ||
-          blockInfo.block.number < lastNotarizedBlock.number) {
-        return;
+      if (!blockInfo.block || !blockInfo.proposal) {
+        break;
       }
-      if (this.checkProposal(blockInfo.block, blockInfo.proposal) ||
-          this.blockPool.hasSeenBlock(blockInfo.block)) {
-        if (blockInfo.votes) {
-          blockInfo.votes.forEach((vote) => {
-            this.blockPool.addSeenVote(vote);
-          });
+      if (blockInfo.block.number < lastNotarizedBlock.number) {
+        continue;
+      }
+      try {
+        this.checkProposal(blockInfo.block, blockInfo.proposal);
+      } catch (e) {
+        if (e instanceof ConsensusError) {
+          e.log();
+        } else {
+          logger.error(`[${LOG_HEADER}] Error while checking proposal: ${e.stack}`);
         }
-        if (!lastVerifiedBlock || lastVerifiedBlock.epoch < blockInfo.block.epoch) {
-          lastVerifiedBlock = blockInfo.block;
+        if (!this.blockPool.hasSeenBlock(blockInfo.block.hash)) {
+          break;
         }
       }
-    });
+      if (blockInfo.votes) {
+        blockInfo.votes.forEach((vote) => {
+          this.blockPool.addSeenVote(vote);
+        });
+      }
+      if (!lastVerifiedBlock || lastVerifiedBlock.epoch < blockInfo.block.epoch) {
+        lastVerifiedBlock = blockInfo.block;
+      }
+    }
 
     this.tryFinalize();
     // Try voting for the last block
     if (lastVerifiedBlock) {
       logger.info(`[${LOG_HEADER}] voting for the last verified block: ` +
           `${lastVerifiedBlock.number} / ${lastVerifiedBlock.epoch}`);
-      this.tryVote(lastVerifiedBlock);
+      this.tryVoteForValidBlock(lastVerifiedBlock);
     }
   }
 
   getLongestNotarizedChain() {
     const lastNotarizedBlock = this.getLastNotarizedBlock();
-    return this.blockPool.getExtendingChain(lastNotarizedBlock.hash);
+    return this.blockPool.getExtendingChain(lastNotarizedBlock.hash, false, true);
   }
 
   // Returns the last block of the longest notarized chain that was proposed
@@ -861,7 +1068,7 @@ class Consensus {
       return res;
     }
     this.blockPool.longestNotarizedChainTips.forEach((chainTip) => {
-      const chain = this.blockPool.getExtendingChain(chainTip, true);
+      const { chain } = this.blockPool.getExtendingChain(chainTip, true);
       res = _.unionWith(res, chain, (a, b) => _.get(a, 'block.hash') === _.get(b, 'block.hash'));
     });
     return res;
@@ -942,18 +1149,32 @@ class Consensus {
     return whitelist || {};
   }
 
-  getValidators(blockHash, blockNumber) {
+  getValidators(blockHash, blockNumber, stateVersion) {
     const LOG_HEADER = 'getValidators';
+    let candidates = [];
+    const validators = {};
+    // Need the block #1 to be finalized to have the stakes reflected in the state.
+    if (this.node.bc.lastBlockNumber() < 1) {
+      for (const address of Object.keys(GENESIS_WHITELIST)) {
+        const stake = this.getConsensusStakeFromAddr(stateVersion, address);
+        if (stake && stake >= MIN_STAKE_PER_VALIDATOR && stake <= MAX_STAKE_PER_VALIDATOR) {
+          validators[address] = {
+            [PredefinedDbPaths.CONSENSUS_STAKE]: stake,
+            [PredefinedDbPaths.CONSENSUS_PROPOSAL_RIGHT]: true
+          };
+        }
+      }
+      logger.debug(`[${LOG_HEADER}] validators: ${JSON.stringify(validators)}`);
+      return validators;
+    }
     const db = this.blockPool.hashToDb.get(blockHash);
-    const stateVersion = this.node.bc.lastBlock().hash === blockHash ?
+    stateVersion = this.node.bc.lastBlock().hash === blockHash ?
         this.node.stateManager.getFinalVersion() : (db ? db.stateVersion : null);
     if (!stateVersion) {
       const err = `[${LOG_HEADER}] No stateVersion found for block ${blockHash}, ${blockNumber}`;
       logger.error(err);
       throw Error(err);
     }
-    let candidates = [];
-    const validators = {};
     const whitelist = this.getWhitelist(stateVersion);
     const stateRoot = this.node.stateManager.getRoot(stateVersion);
     const allStakeInfo = DB.getValueFromStateRoot(
@@ -962,10 +1183,10 @@ class Consensus {
       const stake = this.getConsensusStakeFromAddr(stateVersion, address);
       if (stake) {
         if (whitelist[address] === true) {
-          if (MIN_STAKE_PER_VALIDATOR <= stake && stake <= MAX_STAKE_PER_VALIDATOR) {
+          if (stake >= MIN_STAKE_PER_VALIDATOR && stake <= MAX_STAKE_PER_VALIDATOR) {
             validators[address] = {
-              [PredefinedDbPaths.STAKE]: stake,
-              [PredefinedDbPaths.PROPOSAL_RIGHT]: true
+              [PredefinedDbPaths.CONSENSUS_STAKE]: stake,
+              [PredefinedDbPaths.CONSENSUS_PROPOSAL_RIGHT]: true
             };
           }
         } else {
@@ -982,8 +1203,8 @@ class Consensus {
     for (const candidate of candidates) {
       if (Object.keys(validators).length < MAX_NUM_VALIDATORS) {
         validators[candidate.address] = {
-          [PredefinedDbPaths.STAKE]: candidate.stake,
-          [PredefinedDbPaths.PROPOSAL_RIGHT]: false
+          [PredefinedDbPaths.CONSENSUS_STAKE]: candidate.stake,
+          [PredefinedDbPaths.CONSENSUS_PROPOSAL_RIGHT]: false
         };
       } else {
         break;
@@ -1006,7 +1227,14 @@ class Consensus {
     const blockInfo = this.blockPool.hashToBlockInfo[blockHash];
     if (!blockInfo || !blockInfo.votes) return false;
     const myAddr = this.node.account.address;
-    return blockInfo.votes.filter((vote) => vote.address === myAddr).length > 0;
+    return blockInfo.votes.find((vote) => vote.address === myAddr) !== undefined;
+  }
+
+  votedForBlock(blockHash) {
+    const blockInfo = this.blockPool.hashToBlockInfo[blockHash] || this.blockPool.hashToInvalidBlockInfo[blockHash];
+    if (!blockInfo || !blockInfo.votes) return false;
+    const myAddr = this.node.account.address;
+    return blockInfo.votes.find((vote) => vote.address === myAddr) !== undefined;
   }
 
   stake(amount) {
@@ -1148,6 +1376,7 @@ class Consensus {
     if (this.blockPool) {
       result.block_pool = {
         hashToBlockInfo: this.blockPool.hashToBlockInfo,
+        hashToInvalidBlockInfo: this.blockPool.hashToInvalidBlockInfo,
         hashToDb: Array.from(this.blockPool.hashToDb.keys()),
         hashToNextBlockSet: Object.keys(this.blockPool.hashToNextBlockSet)
           .reduce((acc, curr) => {
@@ -1206,18 +1435,16 @@ class Consensus {
     const LOG_HEADER = 'selectProposer';
     logger.debug(`[${LOG_HEADER}] seed: ${seed}, validators: ${JSON.stringify(validators)}`);
     const validatorsWithProducingRights = _.pickBy(validators, (x) => {
-      return _.get(x, PredefinedDbPaths.PROPOSAL_RIGHT) === true;
+      return _.get(x, PredefinedDbPaths.CONSENSUS_PROPOSAL_RIGHT) === true;
     });
     const alphabeticallyOrderedValidators = Object.keys(validatorsWithProducingRights).sort();
-    const totalAtStake = Object.values(validatorsWithProducingRights).reduce((acc, cur) => {
-      return acc + cur[PredefinedDbPaths.STAKE];
-    }, 0);
+    const totalAtStake = ConsensusUtil.getTotalAtStake(validatorsWithProducingRights);
     const randomNumGenerator = seedrandom(seed);
     const targetValue = randomNumGenerator() * totalAtStake;
     let cumulative = 0;
     for (let i = 0; i < alphabeticallyOrderedValidators.length; i++) {
       const addr = alphabeticallyOrderedValidators[i];
-      cumulative += validatorsWithProducingRights[addr][PredefinedDbPaths.STAKE];
+      cumulative += validatorsWithProducingRights[addr][PredefinedDbPaths.CONSENSUS_STAKE];
       if (cumulative > targetValue) {
         logger.info(`Proposer is ${addr}`);
         return addr;
@@ -1229,35 +1456,6 @@ class Consensus {
         `totalAtStake: ${totalAtStake}\nseed: ${seed}\ntargetValue: ${targetValue}`);
     return null;
   }
-
-  static isValidConsensusTx(tx) {
-    if (!tx.tx_body.operation) return false;
-    const consensusTxPrefix = CommonUtil.formatPath(
-        [PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.NUMBER]);
-    if (tx.tx_body.operation.type === WriteDbOperations.SET_VALUE) {
-      return tx.tx_body.operation.ref.startsWith(consensusTxPrefix);
-    } else if (tx.tx_body.operation.type === WriteDbOperations.SET) {
-      const opList = tx.tx_body.operation.op_list;
-      if (!opList || opList.length !== 2) {
-        return false;
-      }
-      opList.forEach((op) => {
-        if (!op.ref.startsWith(consensusTxPrefix)) return false;
-      })
-      return true;
-    } else {
-      return false;
-    }
-  }
-
-  static filterStakeTxs(txs) {
-    return txs.filter((tx) => {
-      const ref = _.get(tx, 'tx_body.operation.ref');
-      return ref &&
-          ref.startsWith(`/${PredefinedDbPaths.STAKING}/${PredefinedDbPaths.CONSENSUS}`) &&
-          _.get(tx, 'tx_body.operation.type') === WriteDbOperations.SET_VALUE;
-    });
-  }
 }
 
 module.exports = Consensus;
diff --git a/db/functions.js b/db/functions.js
index a199775e0..2f5eabfe4 100644
--- a/db/functions.js
+++ b/db/functions.js
@@ -13,14 +13,15 @@ const {
   ShardingProtocols,
   GenesisAccounts,
   AccountProperties,
+  TokenBridgeProperties,
   TokenExchangeSchemes,
-  FunctionProperties,
   OwnerProperties,
   GasFeeConstants,
   REST_FUNCTION_CALL_TIMEOUT_MS,
   buildOwnerPermissions,
   buildRulePermission,
 } = require('../common/constants');
+const { ConsensusConsts } = require('../consensus/constants');
 const CommonUtil = require('../common/common-util');
 const PathUtil = require('../common/path-util');
 const {
@@ -50,8 +51,12 @@ class Functions {
     this.nativeFunctionMap = {
       [NativeFunctionIds.CLAIM]: {
         func: this._claim.bind(this), ownerOnly: true, extraGasAmount: 0 },
+      [NativeFunctionIds.CLAIM_REWARD]: {
+        func: this._claimReward.bind(this), ownerOnly: true, extraGasAmount: 0 },
       [NativeFunctionIds.CLOSE_CHECKIN]: {
         func: this._closeCheckin.bind(this), ownerOnly: true, extraGasAmount: 10 },
+      [NativeFunctionIds.CLOSE_CHECKOUT]: {
+        func: this._closeCheckout.bind(this), ownerOnly: true, extraGasAmount: 0 },
       [NativeFunctionIds.COLLECT_FEE]: {
         func: this._collectFee.bind(this), ownerOnly: true, extraGasAmount: 0 },
       [NativeFunctionIds.CREATE_APP]: {
@@ -60,10 +65,14 @@ class Functions {
         func: this._distributeFee.bind(this), ownerOnly: true, extraGasAmount: 0 },
       [NativeFunctionIds.ERASE_VALUE]: {
         func: this._eraseValue.bind(this), ownerOnly: false, extraGasAmount: 0 },
+      [NativeFunctionIds.HANDLE_OFFENSES]: {
+        func: this._handleOffenses.bind(this), ownerOnly: true, extraGasAmount: 0 },
       [NativeFunctionIds.HOLD]: {
         func: this._hold.bind(this), ownerOnly: true, extraGasAmount: 0 },
       [NativeFunctionIds.OPEN_CHECKIN]: {
         func: this._openCheckin.bind(this), ownerOnly: true, extraGasAmount: 60 },
+      [NativeFunctionIds.OPEN_CHECKOUT]: {
+        func: this._openCheckout.bind(this), ownerOnly: true, extraGasAmount: 0 },
       [NativeFunctionIds.PAY]: {
         func: this._pay.bind(this), ownerOnly: true, extraGasAmount: 0 },
       [NativeFunctionIds.RELEASE]: {
@@ -95,7 +104,7 @@ class Functions {
    */
   // NOTE(platfowner): Validity checks on individual addresses are done by .write rules.
   // TODO(platfowner): Trigger subtree functions.
-  triggerFunctions(parsedValuePath, value, auth, timestamp, transaction) {
+  triggerFunctions(parsedValuePath, value, auth, timestamp, transaction, blockTime) {
     // NOTE(platfowner): It is assumed that the given transaction is in an executable form.
     const executedAt = transaction.extra.executed_at;
     const matched = this.db.matchFunctionForParsedPath(parsedValuePath);
@@ -110,7 +119,7 @@ class Functions {
 
     if (functionList && functionList.length > 0) {
       const formattedParams = Functions.formatFunctionParams(
-          parsedValuePath, functionPath, timestamp, executedAt, params, value, transaction);
+          parsedValuePath, functionPath, timestamp, executedAt, params, value, transaction, blockTime);
       for (const functionEntry of functionList) {
         if (!functionEntry || !functionEntry.function_type) {
           continue;  // Does nothing.
@@ -149,6 +158,7 @@ class Functions {
                     timestamp,
                     executedAt,
                     transaction,
+                    blockTime,
                     auth: newAuth,
                     opResultList: [],
                     otherGasAmount: 0,
@@ -159,10 +169,10 @@ class Functions {
                     `  ==>| Execution result of NATIVE function [[ ${functionEntry.function_id} ]] ` +
                     `with call stack ${JSON.stringify(this.getFids())}:\n` +
                     `${JSON.stringify(result, null, 2)}`;
-                if (result.code === FunctionResultCode.SUCCESS) {
-                  logger.info(formattedResult);
-                } else {
+                if (CommonUtil.isFailedFuncResultCode(result.code)) {
                   logger.error(formattedResult);
+                } else {
+                  logger.info(formattedResult);
                 }
               }
             } finally {
@@ -268,13 +278,14 @@ class Functions {
   }
 
   static formatFunctionParams(
-      parsedValuePath, functionPath, timestamp, executedAt, params, value, transaction) {
+      parsedValuePath, functionPath, timestamp, executedAt, params, value, transaction, blockTime) {
     return `valuePath: '${CommonUtil.formatPath(parsedValuePath)}', ` +
       `functionPath: '${CommonUtil.formatPath(functionPath)}', ` +
       `timestamp: '${timestamp}', executedAt: '${executedAt}', ` +
       `params: ${JSON.stringify(params, null, 2)}, ` +
       `value: '${JSON.stringify(value, null, 2)}', ` +
-      `transaction: ${JSON.stringify(transaction, null, 2)}`;
+      `transaction: ${JSON.stringify(transaction, null, 2)}, ` +
+      `blockTime: ${blockTime}`;
   }
 
   static getFunctionList(functionMap) {
@@ -608,9 +619,8 @@ class Functions {
 
   _collectFee(value, context) {
     const from = context.params.from;
-    const blockNumber = context.params.block_number;
     const gasFeeServiceAccountName = CommonUtil.toServiceAccountName(
-        PredefinedDbPaths.GAS_FEE, PredefinedDbPaths.GAS_FEE, blockNumber);
+        PredefinedDbPaths.GAS_FEE, PredefinedDbPaths.GAS_FEE, PredefinedDbPaths.GAS_FEE_UNCLAIMED);
     const result =
         this.setServiceAccountTransferOrLog(from, gasFeeServiceAccountName, value.amount, context);
     if (!CommonUtil.isFailedTx(result)) {
@@ -621,23 +631,100 @@ class Functions {
     }
   }
 
+  incrementConsensusRewards(address, amount, context) {
+    const rewardsPath = PathUtil.getConsensusRewardsPath(address);
+    const prevRewards = this.db.getValue(rewardsPath) || {};
+    return this.setValueOrLog(rewardsPath, {
+      [PredefinedDbPaths.CONSENSUS_REWARDS_UNCLAIMED]: (prevRewards[PredefinedDbPaths.CONSENSUS_REWARDS_UNCLAIMED] || 0) + amount,
+      [PredefinedDbPaths.CONSENSUS_REWARDS_CUMULATIVE]: (prevRewards[PredefinedDbPaths.CONSENSUS_REWARDS_CUMULATIVE] || 0) + amount
+    }, context);
+  }
+
   _distributeFee(value, context) {
     const blockNumber = context.params.number;
-    const gasCostTotal = value.gas_cost_total;
-    const proposer = value.proposer;
+    // NOTE(liayoo): Because we need to have the votes to determine which validators to give the
+    //               rewards to, we're distributing the rewards from the (N-1)th block when a
+    //               proposal for the Nth block is written. Genesis block doesn't have rewards,
+    //               so we can start from block number 2 (= processing block number 1) and so on.
+    if (blockNumber <= 1) {
+      return this.returnFuncResult(context, FunctionResultCode.SUCCESS);
+    }
+    const lastConsensusRound = this.db.getValue(PathUtil.getConsensusNumberPath(blockNumber - 1));
+    const gasCostTotal = lastConsensusRound.propose.gas_cost_total;
     if (gasCostTotal <= 0) {
       return this.returnFuncResult(context, FunctionResultCode.SUCCESS);
     }
+    const proposer = lastConsensusRound.propose.proposer;
+    const blockHash = lastConsensusRound.propose.block_hash;
+    const votes = lastConsensusRound[blockHash].vote;
+    const totalAtStake = Object.values(votes).reduce((acc, cur) => acc + cur.stake, 0);
+    const validators = Object.keys(votes);
+    const proposerReward = gasCostTotal / 2;
+    const validatorRewardTotal = gasCostTotal - proposerReward;
+    this.incrementConsensusRewards(proposer, proposerReward, context);
+    let rewardSum = 0;
+    validators.forEach((validator, index) => {
+      const validatorStake = votes[validator].stake;
+      let validatorReward = 0;
+      if (index === validators.length - 1) {
+        validatorReward = validatorRewardTotal - rewardSum;
+      } else {
+        validatorReward = validatorRewardTotal * (validatorStake / totalAtStake);
+        rewardSum += validatorReward;
+      }
+      this.incrementConsensusRewards(validator, validatorReward, context);
+    });
+    return this.returnFuncResult(context, FunctionResultCode.SUCCESS);
+  }
+
+  _claimReward(value, context) {
+    const addr = context.params.user_addr;
+    const unclaimedRewardsPath = PathUtil.getConsensusRewardsUnclaimedPath(addr);
+    const unclaimedRewards = this.db.getValue(unclaimedRewardsPath) || 0;
+    if (unclaimedRewards < value.amount) {
+      return this.returnFuncResult(context, FunctionResultCode.INVALID_AMOUNT);
+    }
     const gasFeeServiceAccountName = CommonUtil.toServiceAccountName(
-        PredefinedDbPaths.GAS_FEE, PredefinedDbPaths.GAS_FEE, blockNumber);
-    const result = this.setServiceAccountTransferOrLog(
-        gasFeeServiceAccountName, proposer, gasCostTotal, context);
-    if (!CommonUtil.isFailedTx(result)) {
-      return this.returnFuncResult(context, FunctionResultCode.SUCCESS);
-    } else {
-      logger.error(`  ===> _distributeFee failed: ${JSON.stringify(result)}`);
+      PredefinedDbPaths.GAS_FEE, PredefinedDbPaths.GAS_FEE, PredefinedDbPaths.GAS_FEE_UNCLAIMED);
+    const transferRes = this.setServiceAccountTransferOrLog(gasFeeServiceAccountName, addr, value.amount, context);
+    if (CommonUtil.isFailedTx(transferRes)) {
+      logger.error(`  ===> _claimReward failed: ${JSON.stringify(transferRes)}`);
       return this.returnFuncResult(context, FunctionResultCode.FAILURE);
     }
+    const updateUnclaimedRes = this.setValueOrLog(unclaimedRewardsPath, unclaimedRewards - value.amount, context);
+    if (CommonUtil.isFailedTx(updateUnclaimedRes)) {
+      logger.error(`  ===> _claimReward failed: ${JSON.stringify(updateUnclaimedRes)}`);
+      return this.returnFuncResult(context, FunctionResultCode.INTERNAL_ERROR);
+    }
+    return this.returnFuncResult(context, FunctionResultCode.SUCCESS);
+  }
+
+  static getLockupExtensionForNewOffenses(numNewOffenses, updatedNumOffenses) {
+    let extension = 0;
+    for (let n = updatedNumOffenses - numNewOffenses + 1; n <= updatedNumOffenses; n++) {
+      extension += ConsensusConsts.STAKE_LOCKUP_EXTENSION * Math.pow(2, n - 1);
+    }
+    return extension;
+  }
+
+  _handleOffenses(value, context) {
+    if (CommonUtil.isEmpty(value.offenses)) {
+      return this.returnFuncResult(context, FunctionResultCode.SUCCESS);
+    }
+    const now = context.blockTime === null ? context.timestamp : context.blockTime;
+    for (const [offender, offenseList] of Object.entries(value.offenses)) {
+      const numNewOffenses = Object.values(offenseList).reduce((acc, cur) => acc + cur, 0);
+      const offenseRecordsPath = PathUtil.getConsensusOffenseRecordsAddrPath(offender);
+      this.incValueOrLog(offenseRecordsPath, numNewOffenses, context);
+      const updatedNumOffenses = this.db.getValue(offenseRecordsPath); // new # of offenses
+      const lockupExtension = Functions.getLockupExtensionForNewOffenses(numNewOffenses, updatedNumOffenses);
+      if (lockupExtension > 0) {
+        const expirationPath = PathUtil.getStakingExpirationPath(PredefinedDbPaths.CONSENSUS, offender, 0);
+        const currentExpiration = Math.max(Number(this.db.getValue(expirationPath)), now);
+        this.setValueOrLog(expirationPath, currentExpiration + lockupExtension, context);
+      }
+    }
+    return this.returnFuncResult(context, FunctionResultCode.SUCCESS);
   }
 
   _stake(value, context) {
@@ -645,25 +732,28 @@ class Functions {
     const user = context.params.user_addr;
     const stakingKey = context.params.staking_key;
     const recordId = context.params.record_id;
-    const timestamp = context.timestamp;
-    const executedAt = context.executedAt;
+    const now = context.blockTime === null ? context.timestamp : context.blockTime;
     const resultPath = PathUtil.getStakingStakeResultPath(serviceName, user, stakingKey, recordId);
     const expirationPath = PathUtil.getStakingExpirationPath(serviceName, user, stakingKey);
-    const lockup = this.db.getValue(PathUtil.getStakingLockupDurationPath(serviceName));
-    if (timestamp > executedAt) {
-      return this.saveAndReturnFuncResult(context, resultPath, FunctionResultCode.FAILURE);
-    }
+    const currentExpiration = Number(this.db.getValue(expirationPath));
+    const lockup = Number(this.db.getValue(PathUtil.getStakingLockupDurationPath(serviceName)));
+    const newExpiration = now + lockup;
+    const updateExpiration = newExpiration > currentExpiration;
     if (value === 0) {
       // Just update the expiration time
-      this.setValueOrLog(expirationPath, Number(timestamp) + Number(lockup), context);
-      return this.saveAndReturnFuncResult(context, resultPath, FunctionResultCode.SUCCESS);
+      if (updateExpiration) {
+        this.setValueOrLog(expirationPath, newExpiration, context);
+        return this.saveAndReturnFuncResult(context, resultPath, FunctionResultCode.SUCCESS);
+      }
     }
     const stakingServiceAccountName = CommonUtil.toServiceAccountName(
           PredefinedDbPaths.STAKING, serviceName, `${user}|${stakingKey}`);
     const result =
         this.setServiceAccountTransferOrLog(user, stakingServiceAccountName, value, context);
     if (!CommonUtil.isFailedTx(result)) {
-      this.setValueOrLog(expirationPath, Number(timestamp) + Number(lockup), context);
+      if (updateExpiration) {
+        this.setValueOrLog(expirationPath, newExpiration, context);
+      }
       const balanceTotalPath = PathUtil.getStakingBalanceTotalPath(serviceName);
       this.incValueOrLog(balanceTotalPath, value, context);
       return this.saveAndReturnFuncResult(context, resultPath, FunctionResultCode.SUCCESS);
@@ -981,6 +1071,158 @@ class Functions {
     }
   }
 
+  updatePendingCheckout(user, amount, isIncrease, context) {
+    if (isIncrease) {
+      if (CommonUtil.isFailedTx(
+          this.incValueOrLog(PathUtil.getCheckoutPendingAmountForAddrPath(user), amount, context))) {
+        return FunctionResultCode.INTERNAL_ERROR;
+      }
+      if (CommonUtil.isFailedTx(
+          this.incValueOrLog(PathUtil.getCheckoutPendingAmountTotalPath(), amount, context))) {
+        return FunctionResultCode.INTERNAL_ERROR;
+      }
+    } else {
+      if (CommonUtil.isFailedTx(
+          this.decValueOrLog(PathUtil.getCheckoutPendingAmountForAddrPath(user), amount, context))) {
+        return FunctionResultCode.INTERNAL_ERROR;
+      }
+      if (CommonUtil.isFailedTx(
+          this.decValueOrLog(PathUtil.getCheckoutPendingAmountTotalPath(), amount, context))) {
+        return FunctionResultCode.INTERNAL_ERROR;
+      }
+    }
+    return true;
+  }
+
+  updateCompleteCheckout(amount, timestamp, context) {
+    const dayTimestamp = CommonUtil.getDayTimestamp(timestamp);
+    if (CommonUtil.isFailedTx(
+        this.incValueOrLog(PathUtil.getCheckoutCompleteAmountDailyPath(dayTimestamp), amount, context))) {
+      return FunctionResultCode.INTERNAL_ERROR;
+    }
+    if (CommonUtil.isFailedTx(
+        this.incValueOrLog(PathUtil.getCheckoutCompleteAmountTotalPath(), amount, context))) {
+      return FunctionResultCode.INTERNAL_ERROR;
+    }
+    return true;
+  }
+
+  validateTokenBridgeConfig(tokenPool, minCheckoutPerRequest, maxCheckoutPerRequest,
+      maxCheckoutPerDay, tokenExchangeRate, tokenExchangeScheme) {
+    if (tokenPool === undefined || minCheckoutPerRequest === undefined ||
+        maxCheckoutPerRequest === undefined || maxCheckoutPerDay === undefined ||
+        tokenExchangeRate === undefined || tokenExchangeScheme === undefined) {
+      return FunctionResultCode.INVALID_TOKEN_BRIDGE_CONFIG;
+    }
+    return true;
+  }
+
+  validateRecipient(recipient, tokenType) {
+    switch (tokenType) {
+      case 'ETH':
+        return CommonUtil.isCksumAddr(recipient) ? true : FunctionResultCode.INVALID_RECIPIENT;
+      // TODO(liayoo): add 'AIN' case for shards
+    }
+    return FunctionResultCode.INVALID_RECIPIENT;
+  }
+
+  validateCheckoutAmount(amount, timestamp, minCheckoutPerRequest, maxCheckoutPerRequest, maxCheckoutPerDay) {
+    const pendingTotal = this.db.getValue(PathUtil.getCheckoutPendingAmountTotalPath()) || 0; // includes 'amount'
+    const checkoutCompleteToday = this.db.getValue(
+        PathUtil.getCheckoutCompleteAmountDailyPath(CommonUtil.getDayTimestamp(timestamp))) || 0;
+    if (amount < minCheckoutPerRequest || amount > maxCheckoutPerRequest) {
+      return FunctionResultCode.INVALID_CHECKOUT_AMOUNT;
+    }
+    if (pendingTotal + checkoutCompleteToday > maxCheckoutPerDay) {
+      return FunctionResultCode.INVALID_CHECKOUT_AMOUNT;
+    }
+    return true;
+  }
+
+  _openCheckout(value, context) {
+    if (value === null) {
+      return this.returnFuncResult(context, FunctionResultCode.SUCCESS);
+    }
+    const user = context.params.user_addr;
+    const { amount, type, token_id: tokenId, recipient } = value;
+    // Increase pending amounts
+    const incPendingResultCode = this.updatePendingCheckout(user, amount, true, context);
+    if (incPendingResultCode !== true) {
+      return this.returnFuncResult(context, incPendingResultCode);
+    }
+    const {
+      [TokenBridgeProperties.TOKEN_POOL]: tokenPool,
+      [TokenBridgeProperties.MIN_CHECKOUT_PER_REQUEST]: minCheckoutPerRequest,
+      [TokenBridgeProperties.MAX_CHECKOUT_PER_REQUEST]: maxCheckoutPerRequest,
+      [TokenBridgeProperties.MAX_CHECKOUT_PER_DAY]: maxCheckoutPerDay,
+      [TokenBridgeProperties.TOKEN_EXCH_RATE]: tokenExchangeRate,
+      [TokenBridgeProperties.TOKEN_EXCH_SCHEME]: tokenExchangeScheme,
+    } = this.db.getValue(PathUtil.getTokenBridgeConfigPath(type, tokenId));
+    // Perform checks
+    const tokenBridgeValidated = this.validateTokenBridgeConfig(
+        tokenPool, minCheckoutPerRequest, maxCheckoutPerRequest, maxCheckoutPerDay,
+        tokenExchangeRate, tokenExchangeScheme);
+    if (tokenBridgeValidated !== true) {
+      return this.returnFuncResult(context, tokenBridgeValidated);
+    }
+    const recipientValidated = this.validateRecipient(recipient, type);
+    if (recipientValidated !== true) {
+      return this.returnFuncResult(context, recipientValidated);
+    }
+    const amountValidated = this.validateCheckoutAmount(
+        amount, context.timestamp, minCheckoutPerRequest, maxCheckoutPerRequest, maxCheckoutPerDay);
+    if (amountValidated !== true) {
+      return this.returnFuncResult(context, amountValidated);
+    }
+    // Transfer from user to token_pool
+    const transferRes = this.setServiceAccountTransferOrLog(user, tokenPool, amount, context);
+    if (!CommonUtil.isFailedTx(transferRes)) {
+      // NOTE(liayoo): History will be recorded by a checkout server after processing the request.
+      return this.returnFuncResult(context, FunctionResultCode.SUCCESS);
+    } else {
+      logger.error(`  ===> _openCheckout failed: ${JSON.stringify(transferRes)}`);
+      return this.returnFuncResult(context, FunctionResultCode.FAILURE);
+    }
+  }
+
+  _closeCheckout(value, context) {
+    const user = context.params.user_addr;
+    const checkoutId = context.params.checkout_id;
+    const { request, response } = value;
+    if (response.status === FunctionResultCode.SUCCESS) {
+      // Increase complete amounts
+      const updateStatsResultCode = this.updateCompleteCheckout(request.amount, context.timestamp, context);
+      if (updateStatsResultCode !== true) {
+        return this.returnFuncResult(context, updateStatsResultCode);
+      }
+    } else {
+      // Refund
+      const tokenPool = this.db.getValue(PathUtil.getTokenBridgeTokenPoolPath(request.type, request.token_id));
+      const transferRes = this.setServiceAccountTransferOrLog(tokenPool, user, request.amount, context);
+      if (CommonUtil.isFailedTx(transferRes)) {
+        return this.returnFuncResult(context, FunctionResultCode.FAILURE);
+      }
+      const setRefundRes = this.setValueOrLog(
+            PathUtil.getCheckoutHistoryRefundPath(user, checkoutId),
+            PathUtil.getTransferPath(tokenPool, user, context.timestamp), context);
+      if (CommonUtil.isFailedTx(setRefundRes)) {
+        return this.returnFuncResult(context, FunctionResultCode.FAILURE);
+      }
+    }
+    // NOTE(liayoo): Remove the original request to avoid keeping the processed requests in the
+    //               /checkout/requests and having to read and filter from the growing list.
+    const removeRes = this.setValueOrLog(PathUtil.getCheckoutRequestPath(user, checkoutId), null, context);
+    if (CommonUtil.isFailedTx(removeRes)) {
+      return this.returnFuncResult(context, FunctionResultCode.FAILURE);
+    }
+    // Decrease pending amounts
+    const decPendingResultCode = this.updatePendingCheckout(user, request.amount, false, context);
+    if (decPendingResultCode !== true) {
+      return this.returnFuncResult(context, decPendingResultCode);
+    }
+    return this.returnFuncResult(context, FunctionResultCode.SUCCESS);
+  }
+
   validateCheckinParams(params) {
     const user = params.user_addr;
     const checkInId = params.checkin_id;
diff --git a/db/index.js b/db/index.js
index 6c549d9a1..1fbf6fe1e 100644
--- a/db/index.js
+++ b/db/index.js
@@ -7,7 +7,6 @@ const {
   PredefinedDbPaths,
   OwnerProperties,
   RuleProperties,
-  ProofProperties,
   StateInfoProperties,
   ShardingProperties,
   GenesisAccounts,
@@ -15,8 +14,8 @@ const {
   StateVersions,
   buildOwnerPermissions,
   LIGHTWEIGHT,
-  TREE_HEIGHT_LIMIT,
-  TREE_SIZE_LIMIT,
+  STATE_TREE_HEIGHT_LIMIT,
+  TREE_SIZE_BUDGET,
   SERVICE_TREE_SIZE_BUDGET,
   APPS_TREE_SIZE_BUDGET,
   FREE_TREE_SIZE_BUDGET,
@@ -46,8 +45,9 @@ const {
   isValidOwnerTree,
   applyFunctionChange,
   applyOwnerChange,
-  setProofHashForStateTree,
-  updateProofHashForAllRootPaths,
+  updateStateInfoForAllRootPaths,
+  updateStateInfoForStateTree,
+  getProofOfStatePath,
 } = require('./state-util');
 const Functions = require('./functions');
 const RuleUtil = require('./rule-util');
@@ -385,23 +385,19 @@ class DB {
   }
 
   static writeToStateRoot(stateRoot, stateVersion, fullPath, stateObj) {
-    const stateTree = StateNode.fromJsObject(stateObj, stateVersion);
-    const pathToParent = fullPath.slice().splice(0, fullPath.length - 1);
+    const tree = StateNode.fromJsObject(stateObj, stateVersion);
+    if (!LIGHTWEIGHT) {
+      updateStateInfoForStateTree(tree);
+    }
     if (fullPath.length === 0) {
-      stateRoot = stateTree;
+      stateRoot = tree;
     } else {
-      const label = fullPath[fullPath.length - 1];
+      const pathToParent = fullPath.slice(0, fullPath.length - 1);
+      const treeLabel = fullPath[fullPath.length - 1];
       const parent = DB.getRefForWritingToStateRoot(stateRoot, pathToParent);
-      parent.setChild(label, stateTree);
-    }
-    if (isEmptyNode(stateTree)) {
-      DB.removeEmptyNodesFromStateRoot(stateRoot, fullPath);
-    } else if (!LIGHTWEIGHT) {
-      setProofHashForStateTree(stateTree);
-    }
-    if (!LIGHTWEIGHT) {
-      updateProofHashForAllRootPaths(pathToParent, stateRoot);
+      parent.setChild(treeLabel, tree);
     }
+    updateStateInfoForAllRootPaths(fullPath, stateRoot);
     return stateRoot;
   }
 
@@ -409,27 +405,6 @@ class DB {
     this.stateRoot = DB.writeToStateRoot(this.stateRoot, this.stateVersion, fullPath, stateObj);
   }
 
-  static removeEmptyNodesRecursive(fullPath, depth, curDbNode) {
-    if (depth < fullPath.length - 1) {
-      const nextDbNode = curDbNode.getChild(fullPath[depth]);
-      if (nextDbNode === null) {
-        logger.error(`Unavailable path in the database: ${CommonUtil.formatPath(fullPath)}`);
-      } else {
-        DB.removeEmptyNodesRecursive(fullPath, depth + 1, nextDbNode);
-      }
-    }
-    for (const label of curDbNode.getChildLabels()) {
-      const childNode = curDbNode.getChild(label);
-      if (isEmptyNode(childNode)) {
-        curDbNode.deleteChild(label);
-      }
-    }
-  }
-
-  static removeEmptyNodesFromStateRoot(stateRoot, fullPath) {
-    return DB.removeEmptyNodesRecursive(fullPath, 0, stateRoot);
-  }
-
   static readFromStateRoot(stateRoot, rootLabel, refPath, options, shardingPath) {
     const isGlobal = options && options.isGlobal;
     if (!stateRoot) return null;
@@ -475,22 +450,7 @@ class DB {
   // TODO(platfowner): Consider supporting global path for getStateProof().
   getStateProof(statePath) {
     const parsedPath = CommonUtil.parsePath(statePath);
-    let node = this.stateRoot;
-    const rootProof = {[ProofProperties.PROOF_HASH]: node.getProofHash()};
-    let proof = rootProof;
-    for (const label of parsedPath) {
-      if (node.hasChild(label)) {
-        node.getChildLabels().forEach((label) => {
-          Object.assign(proof,
-              {[label]: {[ProofProperties.PROOF_HASH]: node.getChild(label).getProofHash()}});
-        });
-        proof = proof[label];
-        node = node.getChild(label);
-      } else {
-        return null;
-      }
-    }
-    return rootProof;
+    return getProofOfStatePath(this.stateRoot, parsedPath);
   }
 
   static getValueFromStateRoot(stateRoot, statePath, isShallow = false) {
@@ -686,7 +646,7 @@ class DB {
   // TODO(platfowner): Define error code explicitly.
   // TODO(platfowner): Apply .shard (isWritablePathWithSharding()) to setFunction(), setRule(),
   //                   and setOwner() as well.
-  setValue(valuePath, value, auth, timestamp, transaction, options) {
+  setValue(valuePath, value, auth, timestamp, transaction, blockTime, options) {
     const isGlobal = options && options.isGlobal;
     const isValidObj = isValidJsObjectForStates(value);
     if (!isValidObj.isValid) {
@@ -721,14 +681,14 @@ class DB {
     let funcResults = null;
     if (auth && (auth.addr || auth.fid)) {
       const { func_results } =
-          this.func.triggerFunctions(localPath, valueCopy, auth, timestamp, transaction);
+          this.func.triggerFunctions(localPath, valueCopy, auth, timestamp, transaction, blockTime);
       funcResults = func_results;
     }
 
     return CommonUtil.returnTxResult(0, null, 1, funcResults);
   }
 
-  incValue(valuePath, delta, auth, timestamp, transaction, options) {
+  incValue(valuePath, delta, auth, timestamp, transaction, blockTime, options) {
     const isGlobal = options && options.isGlobal;
     const valueBefore = this.getValue(valuePath, { isShallow: false, isGlobal });
     logger.debug(`VALUE BEFORE:  ${JSON.stringify(valueBefore)}`);
@@ -736,10 +696,10 @@ class DB {
       return CommonUtil.returnTxResult(201, `Not a number type: ${valueBefore} or ${delta}`, 1);
     }
     const valueAfter = CommonUtil.numberOrZero(valueBefore) + delta;
-    return this.setValue(valuePath, valueAfter, auth, timestamp, transaction, options);
+    return this.setValue(valuePath, valueAfter, auth, timestamp, transaction, blockTime, options);
   }
 
-  decValue(valuePath, delta, auth, timestamp, transaction, options) {
+  decValue(valuePath, delta, auth, timestamp, transaction, blockTime, options) {
     const isGlobal = options && options.isGlobal;
     const valueBefore = this.getValue(valuePath, { isShallow: false, isGlobal });
     logger.debug(`VALUE BEFORE:  ${JSON.stringify(valueBefore)}`);
@@ -747,7 +707,7 @@ class DB {
       return CommonUtil.returnTxResult(301, `Not a number type: ${valueBefore} or ${delta}`, 1);
     }
     const valueAfter = CommonUtil.numberOrZero(valueBefore) - delta;
-    return this.setValue(valuePath, valueAfter, auth, timestamp, transaction, options);
+    return this.setValue(valuePath, valueAfter, auth, timestamp, transaction, blockTime, options);
   }
 
   setFunction(functionPath, func, auth, options) {
@@ -888,18 +848,18 @@ class DB {
     return globalPath;
   }
 
-  executeSingleSetOperation(op, auth, timestamp, tx) {
+  executeSingleSetOperation(op, auth, timestamp, tx, blockTime) {
     let result;
     switch (op.type) {
       case undefined:
       case WriteDbOperations.SET_VALUE:
-        result = this.setValue(op.ref, op.value, auth, timestamp, tx, CommonUtil.toSetOptions(op));
+        result = this.setValue(op.ref, op.value, auth, timestamp, tx, blockTime, CommonUtil.toSetOptions(op));
         break;
       case WriteDbOperations.INC_VALUE:
-        result = this.incValue(op.ref, op.value, auth, timestamp, tx, CommonUtil.toSetOptions(op));
+        result = this.incValue(op.ref, op.value, auth, timestamp, tx, blockTime, CommonUtil.toSetOptions(op));
         break;
       case WriteDbOperations.DEC_VALUE:
-        result = this.decValue(op.ref, op.value, auth, timestamp, tx, CommonUtil.toSetOptions(op));
+        result = this.decValue(op.ref, op.value, auth, timestamp, tx, blockTime, CommonUtil.toSetOptions(op));
         break;
       case WriteDbOperations.SET_FUNCTION:
         result = this.setFunction(op.ref, op.value, auth, CommonUtil.toSetOptions(op));
@@ -916,11 +876,11 @@ class DB {
     return result;
   }
 
-  executeMultiSetOperation(opList, auth, timestamp, tx) {
+  executeMultiSetOperation(opList, auth, timestamp, tx, blockTime) {
     const resultList = {};
     for (let i = 0; i < opList.length; i++) {
       const op = opList[i];
-      const result = this.executeSingleSetOperation(op, auth, timestamp, tx);
+      const result = this.executeSingleSetOperation(op, auth, timestamp, tx, blockTime);
       resultList[i] = result;
       if (CommonUtil.isFailedTx(result)) {
         break;
@@ -935,7 +895,7 @@ class DB {
     tx.setExtraField('gas', gasAmountTotal);
   }
 
-  executeOperation(op, auth, timestamp, tx) {
+  executeOperation(op, auth, timestamp, tx, blockTime) {
     const gasAmountTotal = {
       bandwidth: { service: 0 },
       state: { service: 0 }
@@ -969,26 +929,14 @@ class DB {
     if (op.type === WriteDbOperations.SET) {
       Object.assign(result, this.executeMultiSetOperation(op.op_list, auth, timestamp, tx));
     } else {
-      Object.assign(result, this.executeSingleSetOperation(op, auth, timestamp, tx));
+      Object.assign(result, this.executeSingleSetOperation(op, auth, timestamp, tx, blockTime));
     }
     const stateUsagePerAppAfter = this.getStateUsagePerApp(op);
     DB.updateGasAmountTotal(tx, gasAmountTotal, result);
     if (!CommonUtil.isFailedTx(result)) {
-      const {
-        [StateInfoProperties.TREE_HEIGHT]: treeHeight,
-        [StateInfoProperties.TREE_SIZE]: treeSize
-      } = this.getStateInfo('/');
-      if (treeHeight > TREE_HEIGHT_LIMIT) {
-        return Object.assign(result, {
-          code: 23,
-          error_message: `Out of tree height limit (${treeHeight} > ${TREE_HEIGHT_LIMIT})`
-        });
-      }
-      if (treeSize > TREE_SIZE_LIMIT) {
-        return Object.assign(result, {
-          code: 24,
-          error_message: `Out of tree size limit (${treeSize} > ${TREE_SIZE_LIMIT})`
-        });
+      const heightCheck = this.checkTreeHeightAndSize();
+      if (CommonUtil.isFailedTx(heightCheck)) {
+        return Object.assign(result, heightCheck);
       }
       // NOTE(platfowner): There is no chance to have invalid gas price as its validity check is
       //                   done in isValidTxBody() when transactions are created.
@@ -1054,7 +1002,7 @@ class DB {
     const usageList = [
       this.getStateInfo(`/${PredefinedDbPaths.VALUES_ROOT}/${path}`),
       this.getStateInfo(`/${PredefinedDbPaths.RULES_ROOT}/${path}`),
-      this.getStateInfo(`/${PredefinedDbPaths.FUNCIONS_ROOT}/${path}`),
+      this.getStateInfo(`/${PredefinedDbPaths.FUNCTIONS_ROOT}/${path}`),
       this.getStateInfo(`/${PredefinedDbPaths.OWNERS_ROOT}/${path}`)
     ];
     const usage = usageList.reduce((acc, cur) => {
@@ -1193,9 +1141,9 @@ class DB {
     executionResult.gas_amount_charged = gasAmountChargedByTransfer;
     executionResult.gas_cost_total = CommonUtil.getTotalGasCost(gasPrice, executionResult.gas_amount_charged);
     if (executionResult.gas_cost_total <= 0) return;
-    const gasFeeCollectPath = PathUtil.getGasFeeCollectPath(billedTo, blockNumber, tx.hash);
+    const gasFeeCollectPath = PathUtil.getGasFeeCollectPath(blockNumber, billedTo, tx.hash);
     const gasFeeCollectRes = this.setValue(
-        gasFeeCollectPath, { amount: executionResult.gas_cost_total }, auth, timestamp, tx);
+        gasFeeCollectPath, { amount: executionResult.gas_cost_total }, auth, timestamp, tx, null);
     if (CommonUtil.isFailedTx(gasFeeCollectRes)) { // Should not happend
       Object.assign(executionResult, {
         code: 18,
@@ -1204,12 +1152,31 @@ class DB {
     }
   }
 
+  static trimExecutionResult(executionResult) {
+    const trimmed = _.pick(executionResult, [
+      PredefinedDbPaths.RECEIPTS_EXEC_RESULT_CODE,
+      PredefinedDbPaths.RECEIPTS_EXEC_RESULT_ERROR_MESSAGE,
+      PredefinedDbPaths.RECEIPTS_EXEC_RESULT_GAS_AMOUNT_CHARGED,
+      PredefinedDbPaths.RECEIPTS_EXEC_RESULT_GAS_COST_TOTAL,
+    ]);
+    if (executionResult[PredefinedDbPaths.RECEIPTS_EXEC_RESULT_RESULT_LIST]) {
+      trimmed[PredefinedDbPaths.RECEIPTS_EXEC_RESULT_RESULT_LIST] = {};
+      for (const [key, val] of Object.entries(executionResult[PredefinedDbPaths.RECEIPTS_EXEC_RESULT_RESULT_LIST])) {
+        trimmed[PredefinedDbPaths.RECEIPTS_EXEC_RESULT_RESULT_LIST][key] = _.pick(val, [
+          PredefinedDbPaths.RECEIPTS_EXEC_RESULT_CODE,
+          PredefinedDbPaths.RECEIPTS_EXEC_RESULT_ERROR_MESSAGE,
+        ]);
+      }
+    }
+    return trimmed;
+  }
+
   recordReceipt(auth, tx, blockNumber, executionResult) {
     const receiptPath = PathUtil.getReceiptPath(tx.hash);
     const receipt = {
       [PredefinedDbPaths.RECEIPTS_ADDRESS]: auth.addr,
       [PredefinedDbPaths.RECEIPTS_BLOCK_NUMBER]: blockNumber,
-      [PredefinedDbPaths.RECEIPTS_EXEC_RESULT]: executionResult
+      [PredefinedDbPaths.RECEIPTS_EXEC_RESULT]: DB.trimExecutionResult(executionResult)
     };
     if (tx.tx_body.billing) {
       receipt[PredefinedDbPaths.RECEIPTS_BILLING] = tx.tx_body.billing;
@@ -1309,7 +1276,7 @@ class DB {
     return true;
   }
 
-  executeTransaction(tx, skipFees = false, restoreIfFails = false, blockNumber = 0) {
+  executeTransaction(tx, skipFees = false, restoreIfFails = false, blockNumber = 0, blockTime = null) {
     const LOG_HEADER = 'executeTransaction';
     const precheckResult = this.precheckTransaction(tx, blockNumber);
     if (precheckResult !== true) {
@@ -1328,7 +1295,7 @@ class DB {
     // NOTE(platfowner): It's not allowed for users to send transactions with auth.fid.
     const auth = { addr: tx.address };
     const timestamp = txBody.timestamp;
-    const executionResult = this.executeOperation(txBody.operation, auth, timestamp, tx, blockNumber);
+    const executionResult = this.executeOperation(txBody.operation, auth, timestamp, tx, blockTime);
     if (CommonUtil.isFailedTx(executionResult)) {
       if (restoreIfFails) {
         this.restoreDb();
@@ -1343,12 +1310,12 @@ class DB {
     return executionResult;
   }
 
-  executeTransactionList(txList, skipFees = false, restoreIfFails = false, blockNumber = 0) {
+  executeTransactionList(txList, skipFees = false, restoreIfFails = false, blockNumber = 0, blockTime = null) {
     const LOG_HEADER = 'executeTransactionList';
     const resList = [];
     for (const tx of txList) {
       const executableTx = Transaction.toExecutable(tx);
-      const res = this.executeTransaction(executableTx, skipFees, restoreIfFails, blockNumber);
+      const res = this.executeTransaction(executableTx, skipFees, restoreIfFails, blockNumber, blockTime);
       if (CommonUtil.isFailedTx(res)) {
         logger.debug(`[${LOG_HEADER}] tx failed: ${JSON.stringify(executableTx, null, 2)}` +
             `\nresult: ${JSON.stringify(res)}`);
@@ -1361,6 +1328,28 @@ class DB {
     return resList;
   }
 
+  checkTreeHeightAndSize() {
+    const {
+      [StateInfoProperties.TREE_HEIGHT]: treeHeight,
+      [StateInfoProperties.TREE_SIZE]: treeSize,
+    } = this.getStateInfo('/');
+    if (treeHeight > STATE_TREE_HEIGHT_LIMIT) {
+      return {
+        code: 23,
+        error_message: `Out of tree height limit (${treeHeight} > ${STATE_TREE_HEIGHT_LIMIT})`
+      };
+    }
+    if (treeSize > TREE_SIZE_BUDGET) {
+      return {
+        code: 24,
+        error_message: `Out of tree size budget (${treeSize} > ${TREE_SIZE_BUDGET})`
+      };
+    }
+    return {
+      code: 0
+    }
+  }
+
   addPathToValue(value, matchedValuePath, closestConfigDepth) {
     const pathToAdd = matchedValuePath.slice(closestConfigDepth, matchedValuePath.length);
     let newValue = value;
diff --git a/db/radix-child-map.js b/db/radix-child-map.js
new file mode 100644
index 000000000..c83c7f481
--- /dev/null
+++ b/db/radix-child-map.js
@@ -0,0 +1,116 @@
+const CommonUtil = require('../common/common-util');
+
+/**
+ * Implements Radix Child Map, which is used as a component of RadixNode.
+ */
+class RadixChildMap {
+  constructor() {
+    this.size = 0;
+    this.childArray = RadixChildMap.initChildArray();
+  }
+
+  static initChildArray() {
+    const arr = [];
+    for (let i = 0; i < 16; i++) {
+      arr.push(null);
+    }
+    return arr;
+  }
+
+  static _labelRadixToIndex(labelRadix) {
+    if (!CommonUtil.isString(labelRadix)) {
+      return -1;
+    }
+    const code = labelRadix.charCodeAt(0);
+    if (code >= 48 && code <= 57) {
+      return code - 48;
+    }
+    if (code >= 97 && code <= 102) {
+      return code - 97 + 10;
+    }
+    return -1;
+  }
+
+  static _indexToLabelRadix(index) {
+    if (!CommonUtil.isInteger(index)) {
+      return '';
+    }
+    let code;
+    if (index >= 0 && index <= 9) {
+      code = index + 48;
+    } else if (index >= 10 && index < 16) {
+      code = index - 10 + 97;
+    } else {
+      return '';
+    }
+    return String.fromCharCode(code);
+  }
+
+  get(labelRadix) {
+    const index = RadixChildMap._labelRadixToIndex(labelRadix);
+    if (index >= 0 && index < 16) {
+      return this.childArray[index];
+    }
+    return undefined;  // Keep compatable with Map.
+  }
+
+  set(labelRadix, child) {
+    const index = RadixChildMap._labelRadixToIndex(labelRadix);
+    if (index >= 0 && index < 16) {
+      const isOverwriting = this._has(index);
+      this.childArray[index] = child;
+      if (!isOverwriting) {
+        this.size++;
+      }
+      return true;
+    }
+    return false;
+  }
+
+  _has(index) {
+    if (index >= 0 && index < 16) {
+      const child = this.childArray[index];
+      return child !== null;
+    }
+    return false;
+  }
+
+  has(labelRadix) {
+    const index = RadixChildMap._labelRadixToIndex(labelRadix);
+    return this._has(index);
+  }
+
+  delete(labelRadix) {
+    const index = RadixChildMap._labelRadixToIndex(labelRadix);
+    if (index >= 0 && index < 16) {
+      if (this._has(index)) {
+        this.childArray[index] = null;
+        this.size--;
+        return true;
+      }
+    }
+    return false;
+  }
+
+  keys() {
+    const keys = [];
+    for (let i = 0; i < 16; i++) {
+      if (this._has(i)) {
+        keys.push(RadixChildMap._indexToLabelRadix(i));
+      }
+    }
+    return keys;
+  }
+
+  values() {
+    const values = [];
+    for (let i = 0; i < 16; i++) {
+      if (this._has(i)) {
+        values.push(this.childArray[i]);
+      }
+    }
+    return values;
+  }
+}
+
+module.exports = RadixChildMap;
\ No newline at end of file
diff --git a/db/radix-node.js b/db/radix-node.js
new file mode 100644
index 000000000..048816ce2
--- /dev/null
+++ b/db/radix-node.js
@@ -0,0 +1,309 @@
+const logger = require('../logger')('RADIX_NODE');
+
+const CommonUtil = require('../common/common-util');
+const {
+  FeatureFlags,
+  HASH_DELIMITER,
+  ProofProperties,
+} = require('../common/constants');
+const RadixChildMap = require('./radix-child-map');
+
+/**
+ * Implements Radix Node, which is used as a component of RadixTree.
+ */
+class RadixNode {
+  constructor() {
+    this.stateNode = null;
+    this.labelRadix = '';
+    this.labelSuffix = '';
+    this.parent = null;
+    if (FeatureFlags.enableArrayRadixChildMap) {
+      this.radixChildMap = new RadixChildMap();
+    } else {
+      this.radixChildMap = new Map();
+    }
+    this.proofHash = null;
+  }
+
+  getStateNode() {
+    return this.stateNode;
+  }
+
+  setStateNode(stateNode) {
+    const LOG_HEADER = 'setStateNode';
+    const StateNode = require('./state-node');
+
+    if (!(stateNode instanceof StateNode)) {
+      logger.error(
+          `[${LOG_HEADER}] Setting with a non-StateNode instance at: ${new Error().stack}.`);
+      // Does nothing.
+      return false;
+    }
+    this.stateNode = stateNode;
+    return true;
+  }
+
+  hasStateNode() {
+    return this.getStateNode() !== null;
+  }
+
+  resetStateNode() {
+    this.stateNode = null;
+  }
+
+  getLabelRadix() {
+    return this.labelRadix;
+  }
+
+  setLabelRadix(labelRadix) {
+    this.labelRadix = labelRadix;
+  }
+
+  resetLabelRadix() {
+    this.setLabelRadix('');
+  }
+
+  getLabelSuffix() {
+    return this.labelSuffix;
+  }
+
+  setLabelSuffix(labelSuffix) {
+    this.labelSuffix = labelSuffix;
+  }
+
+  resetLabelSuffix() {
+    this.setLabelSuffix('');
+  }
+
+  getLabel() {
+    return this.getLabelRadix() + this.getLabelSuffix();
+  }
+
+  getParent() {
+    return this.parent;
+  }
+
+  setParent(parent) {
+    this.parent = parent;
+  }
+
+  hasParent() {
+    return this.getParent() !== null;
+  }
+
+  resetParent() {
+    this.setParent(null);
+  }
+
+  getChild(labelRadix) {
+    const child = this.radixChildMap.get(labelRadix);
+    if (child === undefined) {
+      return null;
+    }
+    return child;
+  }
+
+  setChild(labelRadix, labelSuffix, child) {
+    const LOG_HEADER = 'setChild';
+    if (!CommonUtil.isString(labelRadix) || labelRadix.length !== 1) {
+      logger.error(
+          `[${LOG_HEADER}] Setting a child with invalid label radix ${labelRadix} ` +
+          `at: ${new Error().stack}.`);
+      // Does nothing.
+      return false;
+    }
+    if (!CommonUtil.isString(labelSuffix)) {
+      logger.error(
+          `[${LOG_HEADER}] Setting a child with invalid label suffix ${labelRadix} ` +
+          `at: ${new Error().stack}.`);
+      // Does nothing.
+      return false;
+    }
+    if (this.hasChild(labelRadix)) {
+      logger.error(
+          `[${LOG_HEADER}] Overwriting a child with label radix ${labelRadix} ` +
+          `at: ${new Error().stack}.`);
+      // Does nothing.
+      return false;
+    }
+    this.radixChildMap.set(labelRadix, child);
+    child.setLabelRadix(labelRadix);
+    child.setLabelSuffix(labelSuffix);
+    child.setParent(this);
+    return true;
+  }
+
+  hasChild(labelRadix = null) {
+    if (!labelRadix) {
+      return this.numChildren() > 0;
+    }
+    return this.radixChildMap.has(labelRadix);
+  }
+
+  deleteChild(labelRadix) {
+    const LOG_HEADER = 'deleteChild';
+    if (!CommonUtil.isString(labelRadix) || labelRadix.length !== 1) {
+      logger.error(
+          `[${LOG_HEADER}] Deleting a child with invalid label radix ${labelRadix} ` +
+          `at: ${new Error().stack}.`);
+      // Does nothing.
+      return false;
+    }
+    if (!this.hasChild(labelRadix)) {
+      logger.error(
+          `[${LOG_HEADER}] Deleting a non-existing child with label radix: ${labelRadix} ` +
+          `at: ${new Error().stack}.`);
+      // Does nothing.
+      return false;
+    }
+    const child = this.getChild(labelRadix);
+    this.radixChildMap.delete(labelRadix);
+    child.resetLabelRadix();
+    child.resetLabelSuffix();
+    child.resetParent();
+    return true;
+  }
+
+  getChildLabelRadices() {
+    return [...this.radixChildMap.keys()];
+  }
+
+  getChildNodes() {
+    return [...this.radixChildMap.values()];
+  }
+
+  numChildren() {
+    return this.radixChildMap.size;
+  }
+
+  getProofHash() {
+    return this.proofHash;
+  }
+
+  setProofHash(proofHash) {
+    this.proofHash = proofHash;
+  }
+
+  resetProofHash() {
+    this.setProofHash(null);
+  }
+
+  _buildProofHash() {
+    let preimage = '';
+    if (this.hasStateNode()) {
+      preimage = this.getStateNode().getProofHash();
+    }
+    // NOTE(platfowner): Put delimiter twice to distinguish the state node proof hash and
+    // the radix child proof hash.
+    preimage += `${HASH_DELIMITER}${HASH_DELIMITER}`;
+    preimage += this.getChildNodes().map((child) => {
+      return `${child.getLabel()}${HASH_DELIMITER}${child.getProofHash()}`;
+    }).join(HASH_DELIMITER);
+    return CommonUtil.hashString(preimage);
+  }
+
+  verifyProofHash() {
+    return this.getProofHash() === this._buildProofHash();
+  }
+
+  updateProofHash() {
+    this.setProofHash(this._buildProofHash());
+  }
+
+  updateProofHashForRadixSubtree() {
+    let numAffectedNodes = 0;
+    for (const child of this.getChildNodes()) {
+      numAffectedNodes += child.updateProofHashForRadixSubtree();
+    }
+    this.updateProofHash();
+    numAffectedNodes++;
+
+    return numAffectedNodes;
+  }
+
+  updateProofHashForRadixPath() {
+    let numAffectedNodes = 0;
+    let curNode = this;
+    curNode.updateProofHash();
+    numAffectedNodes++;
+    while (curNode.hasParent()) {
+      curNode = curNode.getParent();
+      curNode.updateProofHash();
+      numAffectedNodes++;
+    }
+    return numAffectedNodes;
+  }
+
+  verifyProofHashForRadixSubtree() {
+    if (!this.verifyProofHash()) {
+      return false;
+    }
+    for (const child of this.getChildNodes()) {
+      if (!child.verifyProofHashForRadixSubtree()) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  getProofOfRadixNode(childLabel = null, childProof = null, stateLabel = null, stateProof = null) {
+    const proof = { [ProofProperties.RADIX_PROOF_HASH]: this.getProofHash() };
+    if (this.hasStateNode()) {
+      Object.assign(proof, {
+        [ProofProperties.LABEL]: stateLabel,
+        [ProofProperties.PROOF_HASH]: stateProof !== null ?
+            stateProof : this.getStateNode().getProofHash()
+      });
+    }
+    if (childLabel === null && stateProof !== null) {
+      return proof;
+    }
+    this.getChildNodes().forEach((child) => {
+      const label = child.getLabel();
+      Object.assign(proof, {
+        [label]: label === childLabel ? childProof : {
+          [ProofProperties.RADIX_PROOF_HASH]: child.getProofHash()
+        }
+      });
+    });
+    return proof;
+  }
+
+  copyFrom(radixNode, newParentStateNode) {
+    if (radixNode.hasStateNode()) {
+      const stateNode = radixNode.getStateNode();
+      this.setStateNode(stateNode);
+      stateNode.addParent(newParentStateNode);
+    }
+    this.setLabelRadix(radixNode.getLabelRadix());
+    this.setLabelSuffix(radixNode.getLabelSuffix());
+    this.setProofHash(radixNode.getProofHash());
+    for (const child of radixNode.getChildNodes()) {
+      const clonedChild = new RadixNode();
+      this.setChild(child.getLabelRadix(), child.getLabelSuffix(), clonedChild);
+      clonedChild.copyFrom(child, newParentStateNode);
+    }
+  }
+
+  /**
+   * Converts the subtree to a js object.
+   * This is for testing / debugging purpose.
+   */
+  toJsObject(withProofHash = false) {
+    const obj = {};
+    if (withProofHash) {
+      obj[ProofProperties.RADIX_PROOF_HASH] = this.getProofHash();
+    }
+    if (this.hasStateNode()) {
+      const stateNode = this.getStateNode();
+      obj[ProofProperties.LABEL] = stateNode.getLabel();
+      obj[ProofProperties.PROOF_HASH] = stateNode.getProofHash();
+    }
+    for (const child of this.getChildNodes()) {
+      obj[child.getLabel()] = child.toJsObject(withProofHash);
+    }
+    return obj;
+  }
+}
+
+module.exports = RadixNode;
\ No newline at end of file
diff --git a/db/radix-tree.js b/db/radix-tree.js
new file mode 100644
index 000000000..9ed2fde61
--- /dev/null
+++ b/db/radix-tree.js
@@ -0,0 +1,359 @@
+const logger = require('../logger')('RADIX_TREE');
+
+const CommonUtil = require('../common/common-util');
+const {
+  FeatureFlags,
+} = require('../common/constants');
+const RadixNode = require('./radix-node');
+
+/**
+ * A database for (label, stateNode) pairs. For efficient update and retrieval of proof hashes,
+ * it uses a radix tree internally.
+ */
+class RadixTree {
+  constructor() {
+    this.root = new RadixNode();
+    this.stateNodeMap = new Map();
+    if (FeatureFlags.enableHexLabelCache) {
+      this.hexLabelCache = new Map();
+    }
+  }
+
+  _toHexLabel(stateLabel) {
+    if (FeatureFlags.enableHexLabelCache) {
+      if (this.hexLabelCache.has(stateLabel)) {
+        return this.hexLabelCache.get(stateLabel);
+      }
+    }
+    const hexLabelWithPrefix = CommonUtil.toHexString(stateLabel);
+    const hexLabel = hexLabelWithPrefix.length >= 2 ? hexLabelWithPrefix.slice(2) : '';
+    if (FeatureFlags.enableHexLabelCache) {
+      this.hexLabelCache.set(stateLabel, hexLabel);
+    }
+    return hexLabel;
+  }
+
+  static _matchLabelSuffix(radixNode, hexLabel, index) {
+    const labelSuffix = radixNode.getLabelSuffix();
+    return labelSuffix.length === 0 ||
+        (labelSuffix.length <= hexLabel.length - index &&
+        hexLabel.startsWith(labelSuffix, index));
+  }
+
+  static _getCommonPrefix(label1, label2) {
+    let labelIndex = 0;
+    while (labelIndex < Math.min(label1.length, label2.length)) {
+      if (label1.charAt(labelIndex) !== label2.charAt(labelIndex)) {
+        break;
+      }
+      labelIndex++;
+    }
+    return label1.slice(0, labelIndex);
+  }
+
+  static _setChildWithLabel(node, childLabel, child) {
+    const labelRadix = childLabel.charAt(0);
+    const labelSuffix = childLabel.slice(1);
+    return node.setChild(labelRadix, labelSuffix, child);
+  }
+
+  _getRadixNodeForReading(hexLabel) {
+    let curNode = this.root
+    let labelIndex = 0;
+    while (labelIndex < hexLabel.length) {
+      const labelRadix = hexLabel.charAt(labelIndex);
+      if (!curNode.hasChild(labelRadix)) {
+        return null;
+      }
+      const child = curNode.getChild(labelRadix);
+      if (!RadixTree._matchLabelSuffix(child, hexLabel, labelIndex + 1)) {
+        return null;
+      }
+      curNode = child;
+      labelIndex += 1 + child.getLabelSuffix().length;
+    }
+    return curNode;
+  }
+
+  _getRadixNodeForWriting(hexLabel) {
+    let curNode = this.root
+    let labelIndex = 0;
+    while (labelIndex < hexLabel.length) {
+      const labelRadix = hexLabel.charAt(labelIndex);
+
+      // Case 1: No child with the label radix.
+      if (!curNode.hasChild(labelRadix)) {
+        const newChild = new RadixNode();
+        const labelSuffix = hexLabel.slice(labelIndex + 1);
+        curNode.setChild(labelRadix, labelSuffix, newChild);
+
+        return newChild;
+      }
+
+      // Case 2: Has a child with the label radix but no match with the label suffix.
+      const child = curNode.getChild(labelRadix);
+      if (!RadixTree._matchLabelSuffix(child, hexLabel, labelIndex + 1)) {
+        const labelSuffix = hexLabel.slice(labelIndex + 1);
+        const childLabelSuffix = child.getLabelSuffix();
+        const commonPrefix = RadixTree._getCommonPrefix(labelSuffix, childLabelSuffix);
+
+        // Delete existing child first.
+        curNode.deleteChild(labelRadix);
+
+        if (commonPrefix.length === labelSuffix.length) {
+          // Insert an internal node between curNode and the existing child.
+          const internalNode = new RadixNode();
+          curNode.setChild(labelRadix, commonPrefix, internalNode);
+
+          // Insert the existing child node as a child of the internal node.
+          const childNewLabel = childLabelSuffix.slice(commonPrefix.length);
+          RadixTree._setChildWithLabel(internalNode, childNewLabel, child);
+
+          // Return the new internal node
+          return internalNode;
+        } else {
+          // Insert an internal node between curNode and two child nodes.
+          const internalNode = new RadixNode();
+          curNode.setChild(labelRadix, commonPrefix, internalNode);
+
+          // Insert the existing child node as a child of the internal node.
+          const childNewLabel = childLabelSuffix.slice(commonPrefix.length);
+          RadixTree._setChildWithLabel(internalNode, childNewLabel, child);
+
+          // Insert new child node as a child of the internal node.
+          const newChild = new RadixNode();
+          const newChildLabel = labelSuffix.slice(commonPrefix.length);
+          RadixTree._setChildWithLabel(internalNode, newChildLabel, newChild);
+
+          return newChild;
+        }
+      }
+
+      // Case 3: Has a child with matching label suffix.
+      curNode = child;
+      labelIndex += 1 + child.getLabelSuffix().length;
+    }
+
+    return curNode;
+  }
+
+  _getFromTree(stateLabel) {
+    const hexLabel = this._toHexLabel(stateLabel);
+    const node = this._getRadixNodeForReading(hexLabel);
+    if (node === null) {
+      return null;
+    }
+    return node.getStateNode();
+  }
+
+  _getFromMap(label) {
+    const child = this.stateNodeMap.get(label);
+    if (child === undefined) {
+      return null;
+    }
+    return child;
+  }
+
+  get(label) {
+    // NOTE(platfowner): Use hash map instead of radix tree as it faster.
+    return this._getFromMap(label);
+  }
+
+  _setInTree(stateLabel, stateNode) {
+    const hexLabel = this._toHexLabel(stateLabel);
+    const node = this._getRadixNodeForWriting(hexLabel);
+    return node.setStateNode(stateNode);
+  }
+
+  _setInMap(label, stateNode) {
+    this.stateNodeMap.set(label, stateNode);
+  }
+
+  set(label, stateNode) {
+    // 1. Set in the radix tree.
+    if (!this._setInTree(label, stateNode)) {
+      return false;
+    }
+    // 2. Set in the hash map.
+    this._setInMap(label, stateNode);
+    return true;
+  }
+
+  _hasInTree(stateLabel) {
+    const hexLabel = this._toHexLabel(stateLabel);
+    const node = this._getRadixNodeForReading(hexLabel);
+    return node !== null;
+  }
+
+  _hasInMap(label) {
+    return this.stateNodeMap.has(label);
+  }
+
+  has(label) {
+    // NOTE(platfowner): Use hash map instead of radix tree as it faster.
+    return this._hasInMap(label);
+  }
+
+  _mergeToChild(node) {
+    const LOG_HEADER = '_mergeToChild';
+
+    if (node.numChildren() !== 1) {
+      logger.error(
+          `[${LOG_HEADER}] Trying to merge a node with children: ${node.getLabel()} ` +
+          `at: ${new Error().stack}.`);
+      // Does nothing.
+      return false;
+    }
+    if (node.hasStateNode()) {
+      logger.error(
+          `[${LOG_HEADER}] Trying to merge a node with state node: ${node.getLabel()} ` +
+          `at: ${new Error().stack}.`);
+      // Does nothing.
+      return false;
+    }
+    const parent = node.getParent();
+    const labelRadix = node.getLabelRadix();
+    const labelSuffix = node.getLabelSuffix();
+    const child = node.getChildNodes()[0];
+    const childLabelRadix = child.getLabelRadix();
+    const childLabelSuffix = child.getLabelSuffix();
+    parent.deleteChild(labelRadix);
+    node.deleteChild(childLabelRadix);
+    const newChildLabelSuffix = labelSuffix + childLabelRadix + childLabelSuffix;
+    parent.setChild(labelRadix, newChildLabelSuffix, child);
+    return true;
+  }
+
+  _deleteFromTree(stateLabel) {
+    const LOG_HEADER = '_deleteFromTree';
+
+    const hexLabel = this._toHexLabel(stateLabel);
+    const node = this._getRadixNodeForReading(hexLabel);
+    if (node === null || !node.hasStateNode()) {
+      logger.error(
+          `[${LOG_HEADER}] Deleting a non-existing child of label: ${stateLabel} ` +
+          `at: ${new Error().stack}.`);
+      // Does nothing.
+      return false;
+    }
+    if (!node.hasParent()) {
+      logger.error(
+          `[${LOG_HEADER}] Deleting the root node of label: ${stateLabel} ` +
+          `at: ${new Error().stack}.`);
+      // Does nothing.
+      return false;
+    }
+    node.resetStateNode();
+    if (node.numChildren() === 1) {
+      return this._mergeToChild(node);
+    } else if (node.numChildren() === 0) {
+      if (!node.hasParent()) {
+        logger.error(
+            `[${LOG_HEADER}] Deleting a child without parent of label: ${stateLabel} ` +
+            `at: ${new Error().stack}.`);
+        // Does nothing.
+        return false;
+      }
+      const parent = node.getParent();
+      parent.deleteChild(node.getLabelRadix());
+      if (parent.numChildren() === 1 && !parent.hasStateNode() && parent.hasParent()) {
+        return this._mergeToChild(parent);
+      }
+    }
+    if (FeatureFlags.enableHexLabelCache) {
+      this.hexLabelCache.delete(stateLabel);
+    }
+    return true;
+  }
+
+  _deleteFromMap(stateLabel) {
+    this.stateNodeMap.delete(stateLabel);
+  }
+
+  delete(stateLabel) {
+    // 1. Delete from the radix tree.
+    this._deleteFromTree(stateLabel);
+    // 2. Delete from the hash map.
+    this._deleteFromMap(stateLabel);
+  }
+
+  labels() {
+    return [...this.stateNodeMap.keys()];
+  }
+
+  stateNodes() {
+    return [...this.stateNodeMap.values()];
+  }
+
+  size() {
+    return this.stateNodeMap.size;
+  }
+
+  getRootProofHash() {
+    return this.root.getProofHash();
+  }
+
+  updateProofHashForRadixTree() {
+    return this.root.updateProofHashForRadixSubtree();
+  }
+
+  updateProofHashForRadixPath(updatedNodeLabel) {
+    const LOG_HEADER = 'updateProofHashForRadixPath';
+
+    const hexLabel = this._toHexLabel(updatedNodeLabel);
+    const node = this._getRadixNodeForReading(hexLabel);
+    if (node === null) {
+      logger.error(
+          `[${LOG_HEADER}] Updating proof hash for non-existing child with label: ` +
+          `${updatedNodeLabel} at: ${new Error().stack}.`);
+      // Does nothing.
+      return 0;
+    }
+    return node.updateProofHashForRadixPath();
+  }
+
+  verifyProofHashForRadixTree() {
+    return this.root.verifyProofHashForRadixSubtree();
+  }
+
+  getProofOfState(stateLabel, stateProof) {
+    const hexLabel = this._toHexLabel(stateLabel);
+    let curNode = this._getRadixNodeForReading(hexLabel);
+    if (curNode === null || !curNode.hasStateNode()) {
+      return null;
+    }
+    let proof = curNode.getProofOfRadixNode(null, null, stateLabel, stateProof);
+    while (curNode.hasParent()) {
+      const label = curNode.getLabel();
+      curNode = curNode.getParent();
+      proof = curNode.getProofOfRadixNode(label, proof);
+    }
+    return proof;
+  }
+
+
+  _copyTreeFrom(radixTree, newParentStateNode) {
+    this.root.copyFrom(radixTree.root, newParentStateNode);
+  }
+
+  _copyMapFrom(radixTree) {
+    radixTree.stateNodeMap.forEach((value, key) => {
+      this._setInMap(key, value);
+    });
+  }
+
+  copyFrom(radixTree, newParentStateNode) {
+    this._copyTreeFrom(radixTree, newParentStateNode);
+    this._copyMapFrom(radixTree);
+  }
+
+  /**
+   * Converts the tree to a javascript object.
+   * This is for testing / debugging purpose.
+   */
+  toJsObject(withProofHash = false, withStateNodeDetails = false) {
+    return this.root.toJsObject(withProofHash, withStateNodeDetails);
+  }
+}
+
+module.exports = RadixTree;
\ No newline at end of file
diff --git a/db/rule-util.js b/db/rule-util.js
index a8cb31efd..fe3f43123 100644
--- a/db/rule-util.js
+++ b/db/rule-util.js
@@ -1,7 +1,7 @@
 const ainUtil = require('@ainblockchain/ain-util');
 const _ = require('lodash');
 
-// NOTE(platfowner): To keep the blockchain deterministic as much as possibble over time,
+// NOTE(platfowner): To keep the blockchain deterministic as much as possible over time,
 //                   we keep util functions here self-contained as much as possible.
 class RuleUtil {
   isBool(value) {
@@ -34,6 +34,14 @@ class RuleUtil {
         (this.isDict(value) && Object.keys(value).length === 0);
   }
 
+  isHexString(value) {
+    return this.isString(value) && /^0x[0-9A-Fa-f]*$/.test(value);
+  }
+
+  isValidHash(value) {
+    return this.isHexString(value) && value.length === 66;
+  }
+
   keys(value) {
     if (this.isDict(value)) {
       return Object.keys(value);
@@ -147,9 +155,8 @@ class RuleUtil {
   }
 
   isAppAdmin(appName, address, getValue) {
-    const { PredefinedDbPaths } = require('../common/constants');
-    return getValue(`/${PredefinedDbPaths.MANAGE_APP}/${appName}/${PredefinedDbPaths.MANAGE_APP_CONFIG}/` +
-        `${PredefinedDbPaths.MANAGE_APP_CONFIG_ADMIN}/${address}`) === true;
+    const PathUtil = require('../common/path-util');
+    return getValue(`${PathUtil.getManageAppConfigAdminPath(appName)}/${address}`) === true;
   }
 
   isAppAdminFromServAcntName(accountName, address, getValue) {
@@ -158,12 +165,12 @@ class RuleUtil {
   }
 
   getBalancePath(addrOrServAcnt) {
-    const { PredefinedDbPaths } = require('../common/constants');
+    const PathUtil = require('../common/path-util');
     if (this.isServAcntName(addrOrServAcnt)) {
       const parsed = this.parseServAcntName(addrOrServAcnt);
-      return `/${PredefinedDbPaths.SERVICE_ACCOUNTS}/${parsed[0]}/${parsed[1]}/${parsed[2]}/${PredefinedDbPaths.BALANCE}`;
+      return PathUtil.getServiceAccountBalancePath(parsed[0], parsed[1], parsed[2]);
     } else {
-      return `/${PredefinedDbPaths.ACCOUNTS}/${addrOrServAcnt}/${PredefinedDbPaths.BALANCE}`;
+      return PathUtil.getAccountBalancePath(addrOrServAcnt);
     }
   }
 
@@ -172,36 +179,16 @@ class RuleUtil {
   }
 
   isBillingUser(billingServAcntName, userAddr, getValue) {
-    const { PredefinedDbPaths } = require('../common/constants');
+    const PathUtil = require('../common/path-util');
     const parsed = this.parseServAcntName(billingServAcntName);
     const appName = parsed[1];
     const billingId = parsed[2];
-    return getValue(
-        `/${PredefinedDbPaths.MANAGE_APP}/${appName}/${PredefinedDbPaths.MANAGE_APP_CONFIG}/` +
-        `${PredefinedDbPaths.MANAGE_APP_CONFIG_BILLING}/${billingId}/` +
-        `${PredefinedDbPaths.MANAGE_APP_CONFIG_BILLING_USERS}/${userAddr}`) === true;
-  }
-
-  isGasFeeCollected(address, newData, txHash, getValue) {
-    const { PredefinedDbPaths } = require('../common/constants');
-    const blockNumber = newData[PredefinedDbPaths.RECEIPTS_BLOCK_NUMBER];
-    const gasCost = _.get(newData, `${PredefinedDbPaths.RECEIPTS_EXEC_RESULT}.${PredefinedDbPaths.RECEIPTS_GAS_COST_TOTAL}`);
-    if (gasCost === undefined) {
-      return false;
-    }
-    const billing = _.get(newData, `${PredefinedDbPaths.RECEIPTS_BILLING}`);
-    const collectedFrom = billing ? `${PredefinedDbPaths.BILLING}|${billing}` : address;
-    const feeCollected = getValue(
-        `/${PredefinedDbPaths.GAS_FEE}/${PredefinedDbPaths.COLLECT}/${collectedFrom}` +
-        `/${blockNumber}/${txHash}/${PredefinedDbPaths.GAS_FEE_AMOUNT}`) || 0;
-    return feeCollected === gasCost;
+    return getValue(`${PathUtil.getManageAppBillingUsersPath(appName, billingId)}/${userAddr}`) === true;
   }
 
   getConsensusStakeBalance(address, getValue) {
-    const { PredefinedDbPaths } = require('../common/constants');
-    return getValue(
-        `/${PredefinedDbPaths.SERVICE_ACCOUNTS}/${PredefinedDbPaths.STAKING}/` +
-        `${PredefinedDbPaths.CONSENSUS}/${address}|0/${PredefinedDbPaths.BALANCE}`) || 0;
+    const PathUtil = require('../common/path-util');
+    return getValue(PathUtil.getConsensusStakingAccountBalancePath(address)) || 0;
   }
 
   getOwnerAddr() {
@@ -223,6 +210,75 @@ class RuleUtil {
     const { MIN_NUM_VALIDATORS } = require('../common/constants');
     return MIN_NUM_VALIDATORS;
   }
+
+  getTokenBridgeConfig(type, tokenId, getValue) {
+    const PathUtil = require('../common/path-util');
+    return getValue(PathUtil.getTokenBridgeConfigPath(type, tokenId));
+  }
+
+  getTokenPoolAddr(type, tokenId, getValue) {
+    const PathUtil = require('../common/path-util');
+    return getValue(PathUtil.getTokenBridgeTokenPoolPath(type, tokenId));
+  }
+
+  getTokenPoolAddrFromHistoryData(userAddr, checkoutId, getValue) {
+    const request = getValue(`/checkout/history/${userAddr}/${checkoutId}/request`);
+    if (!request || !request.type || !request.token_id) {
+      return null;
+    }
+    return this.getTokenPoolAddr(request.type, request.token_id, getValue);
+  }
+
+  validateCheckoutRequestData(data, getValue) {
+    if (!this.isDict(data) || !this.isNumber(data.amount) || data.amount <= 0 ||
+        !this.isString(data.type) || !this.isString(data.token_id) || !this.isString(data.recipient)) {
+      return false;
+    }
+    return this.isDict(this.getTokenBridgeConfig(data.type, data.token_id, getValue));
+  }
+
+  validateCheckoutHistoryData(userAddr, checkoutId, data, getValue) {
+    const { FunctionResultCode } = require('../common/constants');
+    const request = getValue(`/checkout/requests/${userAddr}/${checkoutId}`);
+    if (!request || !this.isDict(request) || !this.isDict(data)) {
+      return false;
+    }
+    if (!_.isEqual(request, data.request, { strict: true })) {
+      return false;
+    }
+    return this.isDict(data.response) && this.isValidHash(data.response.tx_hash) &&
+        (data.response.status === FunctionResultCode.SUCCESS ||
+        data.response.status === FunctionResultCode.FAILURE);
+  }
+
+  validateClaimRewardData(userAddr, data, getValue) {
+    const PathUtil = require('../common/path-util');
+    if (!this.isDict(data) || !this.isNumber(data.amount) || data.amount <= 0) {
+      return false;
+    }
+    const unclaimed = getValue(PathUtil.getConsensusRewardsUnclaimedPath(userAddr)) || 0;
+    return data.amount <= unclaimed;
+  }
+
+  validateCollectFeeData(data, newData, from, getValue) {
+    return data === null && this.isDict(newData) && this.isNumber(newData.amount) &&
+        newData.amount <= this.getBalance(from, getValue);
+  }
+
+  validateConsensusVoteData(data, userAddr, blockHash, lastBlockNumber, getValue) {
+    if (!this.isDict(data) || !this.isBool(data.is_against) || !this.isNumber(data.stake) || data.block_hash !== blockHash) {
+      return false;
+    }
+    if (data.is_against && !this.isValidatorOffenseType(data.offense_type)) {
+      return false;
+    }
+    return lastBlockNumber < 1 || this.getConsensusStakeBalance(userAddr, getValue) === data.stake;
+  }
+
+  isValidatorOffenseType(type) {
+    const { ValidatorOffenseTypes } = require('../consensus/constants');
+    return !!ValidatorOffenseTypes[type];
+  }
 }
 
 module.exports = RuleUtil;
diff --git a/db/state-node.js b/db/state-node.js
index e629c2f0b..8cf109ea9 100644
--- a/db/state-node.js
+++ b/db/state-node.js
@@ -3,28 +3,38 @@ const logger = require('../logger')('STATE_NODE');
 const sizeof = require('object-sizeof');
 const CommonUtil = require('../common/common-util');
 const {
+  FeatureFlags,
   HASH_DELIMITER,
   StateInfoProperties,
+  ProofProperties,
+  LIGHTWEIGHT,
 } = require('../common/constants');
+const RadixTree = require('./radix-tree');
 
 class StateNode {
   // NOTE(seo): Once new member variables are added, computeNodeBytes() should be updated.
   constructor(version) {
     this.version = version || null;
+    this.label = null;
     this.isLeaf = true;
-    this.parentSet = new Set();
-    // Used for internal nodes only.
-    this.childMap = new Map();
     // Used for leaf nodes only.
     this.value = null;
+    this.parentSet = new Set();
+    // Used for internal nodes only.
+    if (FeatureFlags.enableRadixTreeLayers) {
+      this.radixTree = new RadixTree();
+    } else {
+      this.childMap = new Map();
+    }
     this.proofHash = null;
     this.treeHeight = 0;
     this.treeSize = 0;
     this.treeBytes = 0;
   }
 
-  static _create(version, isLeaf, value, proofHash, treeHeight, treeSize, treeBytes) {
+  static _create(version, label, isLeaf, value, proofHash, treeHeight, treeSize, treeBytes) {
     const node = new StateNode(version);
+    node._setLabel(label);
     node.setIsLeaf(isLeaf);
     node.setValue(value);
     node.setProofHash(proofHash);
@@ -35,36 +45,46 @@ class StateNode {
   }
 
   clone(version) {
-    const cloned = StateNode._create(version ? version : this.version,
+    const cloned = StateNode._create(version ? version : this.version, this.label,
         this.isLeaf, this.value, this.proofHash, this.treeHeight, this.treeSize, this.treeBytes);
-    for (const label of this.getChildLabels()) {
-      const child = this.getChild(label);
-      cloned.setChild(label, child);
+    if (FeatureFlags.enableRadixTreeLayers) {
+      cloned.copyRadixTreeFrom(this, cloned);
+    } else {
+      for (const label of this.getChildLabels()) {
+        const child = this.getChild(label);
+        cloned.setChild(label, child);
+      }
     }
     return cloned;
   }
 
+  copyRadixTreeFrom(stateNode, newParentStateNode) {
+    this.radixTree.copyFrom(stateNode.radixTree, newParentStateNode);
+  }
+
   equal(that) {
     if (!that) {
       return false;
     }
-    return (that.isLeaf === this.isLeaf &&
+    return (that.version === this.version &&
+        that.label === this.label &&
+        that.isLeaf === this.isLeaf &&
+        that.value === this.value &&
         that.numParents && typeof that.numParents === 'function' &&
         // NOTE: Compare only numParents() values.
         that.numParents() === this.numParents() &&
         that.getChildLabels && typeof that.getChildLabels === 'function' &&
         // NOTE: The child label order matters.
         JSON.stringify(that.getChildLabels()) === JSON.stringify(this.getChildLabels()) &&
-        that.value === this.value &&
         that.proofHash === this.proofHash &&
-        that.version === this.version &&
         that.treeHeight === this.treeHeight &&
         that.treeSize === this.treeSize &&
         that.treeBytes === this.treeBytes);
   }
 
   // NOTE(liayoo): Bytes for some data (e.g. parents & children references, version) are excluded
-  //               from this calculation, since their sizes can vary and affect the gas costs and state proof hashes.
+  // from this calculation, since their sizes can vary and affect the gas costs and
+  // state proof hashes.
   computeNodeBytes() {
     return sizeof(this.isLeaf) +
         sizeof(this.value) +
@@ -132,6 +152,29 @@ class StateNode {
     return obj;
   }
 
+  getLabel() {
+    return this.label;
+  }
+
+  hasLabel() {
+    return this.getLabel() !== null;
+  }
+
+  _setLabel(label) {
+    const LOG_HEADER = '_setLabel';
+
+    const curLabel = this.getLabel();
+    if (curLabel !== null && curLabel !== label) {
+      logger.error(
+          `[${LOG_HEADER}] Overwriting label ${curLabel} with ${label} at: ${new Error().stack}.`);
+    }
+    this.label = label;
+  }
+
+  _resetLabel() {
+    this.label = null;
+  }
+
   getIsLeaf() {
     return this.isLeaf;
   }
@@ -152,11 +195,12 @@ class StateNode {
     this.setValue(null);
   }
 
-  _addParent(parent) {
+  addParent(parent) {
     const LOG_HEADER = 'addParent';
     if (this._hasParent(parent)) {
       logger.error(
-          `[${LOG_HEADER}] Adding an existing parent: ${JSON.stringify(parent, null, 2)}.`);
+          `[${LOG_HEADER}] Adding an existing parent of label: ${parent.getLabel()} ` +
+          `at: ${new Error().stack}.`);
       // Does nothing.
       return;
     }
@@ -171,7 +215,8 @@ class StateNode {
     const LOG_HEADER = 'deleteParent';
     if (!this.parentSet.has(parent)) {
       logger.error(
-          `[${LOG_HEADER}] Deleting a non-existing parent: ${JSON.stringify(parent, null, 2)}.`);
+          `[${LOG_HEADER}] Deleting a non-existing parent of label: ${parent.getLabel()} ` +
+          `at: ${new Error().stack}.`);
       // Does nothing.
       return;
     }
@@ -187,7 +232,12 @@ class StateNode {
   }
 
   getChild(label) {
-    const child = this.childMap.get(label);
+    let child;
+    if (FeatureFlags.enableRadixTreeLayers) {
+      child = this.radixTree.get(label);
+    } else {
+      child = this.childMap.get(label);
+    }
     if (child === undefined) {
       return null;
     }
@@ -200,7 +250,8 @@ class StateNode {
       const child = this.getChild(label);
       if (child === node) {
         logger.error(
-            `[${LOG_HEADER}] Setting a child with label ${label} which is already a child.`);
+            `[${LOG_HEADER}] Setting a child with label ${label} which is already a child ` +
+            `at: ${new Error().stack}.`);
         // Does nothing.
         return;
       }
@@ -208,42 +259,69 @@ class StateNode {
       //                   to keep the order of children.
       child._deleteParent(this);
     }
-    this.childMap.set(label, node);
-    node._addParent(this);
+    if (FeatureFlags.enableRadixTreeLayers) {
+      this.radixTree.set(label, node);
+    } else {
+      this.childMap.set(label, node);
+    }
+    node.addParent(this);
+    node._setLabel(label);
     if (this.getIsLeaf()) {
       this.setIsLeaf(false);
     }
   }
 
   hasChild(label) {
-    return this.childMap.has(label);
+    if (FeatureFlags.enableRadixTreeLayers) {
+      return this.radixTree.has(label);
+    } else {
+      return this.childMap.has(label);
+    }
   }
 
   deleteChild(label) {
     const LOG_HEADER = 'deleteChild';
     if (!this.hasChild(label)) {
-      logger.error(`[${LOG_HEADER}] Deleting a non-existing child with label: ${label}.`);
+      logger.error(
+          `[${LOG_HEADER}] Deleting a non-existing child with label: ${label} ` +
+          `at: ${new Error().stack}.`);
       // Does nothing.
       return;
     }
     const child = this.getChild(label);
     child._deleteParent(this);
-    this.childMap.delete(label);
+    if (FeatureFlags.enableRadixTreeLayers) {
+      this.radixTree.delete(label);
+    } else {
+      this.childMap.delete(label);
+    }
     if (this.numChildren() === 0) {
       this.setIsLeaf(true);
     }
   }
 
   getChildLabels() {
-    return [...this.childMap.keys()];
+    if (FeatureFlags.enableRadixTreeLayers) {
+      return [...this.radixTree.labels()];
+    } else {
+      return [...this.childMap.keys()];
+    }
   }
 
   getChildNodes() {
-    return [...this.childMap.values()];
+    if (FeatureFlags.enableRadixTreeLayers) {
+      return [...this.radixTree.stateNodes()];
+    } else {
+      return [...this.childMap.values()];
+    }
   }
 
   numChildren() {
-    return this.childMap.size;
+    if (FeatureFlags.enableRadixTreeLayers) {
+      return this.radixTree.size();
+    } else {
+      return this.childMap.size;
+    }
   }
 
   getProofHash() {
@@ -290,20 +368,59 @@ class StateNode {
     this.treeBytes = treeBytes;
   }
 
-  buildProofHash() {
+  /**
+   * Returns newly buildt proof hash. If updatedChildLabel is given, it signifies that
+   * only the child of the given child label among the children is not up-to-date now,
+   * so only the proof hashes of the radix nodes related to the given child label
+   * need to be updated, and this function does so.
+   * 
+   * @param {string} updatedChildLabel label of the child whose proof hash is not up-to-date
+   */
+  // NOTE(platfowner): This function changes proof hashes of the radix tree.
+  buildProofHash(updatedChildLabel = null) {
     let preimage;
     if (this.getIsLeaf()) {
       preimage = this.getValue();
     } else {
-      preimage = this.getChildLabels().map((label) => {
-        return `${label}${HASH_DELIMITER}${this.getChild(label).getProofHash()}`;
-      }, '').join(HASH_DELIMITER);
+      if (FeatureFlags.enableRadixTreeLayers) {
+        if (updatedChildLabel === null) {
+          this.radixTree.updateProofHashForRadixTree();
+        } else {
+          this.radixTree.updateProofHashForRadixPath(updatedChildLabel);
+        }
+        return this.radixTree.getRootProofHash();
+      } else {
+        preimage = this.getChildLabels().map((label) => {
+          return `${label}${HASH_DELIMITER}${this.getChild(label).getProofHash()}`;
+        }).join(HASH_DELIMITER);
+      }
     }
     return CommonUtil.hashString(CommonUtil.toString(preimage));
   }
 
-  verifyProofHash() {
-    return this.getProofHash() === this.buildProofHash();
+  verifyProofHash(updatedChildLabel = null) {
+    return this.getProofHash() === this.buildProofHash(updatedChildLabel);
+  }
+
+  getProofOfState(childLabel = null, childProof = null) {
+    if (childLabel === null) {
+      return { [ProofProperties.PROOF_HASH]: this.getProofHash() };
+    } else {
+      if (FeatureFlags.enableRadixTreeLayers) {
+        return this.radixTree.getProofOfState(childLabel, childProof);
+      } else {
+        const proof = { [ProofProperties.PROOF_HASH]: this.getProofHash() };
+        this.getChildLabels().forEach((label) => {
+          const child = this.getChild(label);
+          Object.assign(proof, {
+            [label]: label === childLabel ? childProof : {
+              [ProofProperties.PROOF_HASH]: child.getProofHash()
+            }
+          });
+        });
+        return proof;
+      }
+    }
   }
 
   computeTreeHeight() {
@@ -335,8 +452,10 @@ class StateNode {
     }
   }
 
-  updateProofHashAndStateInfo() {
-    this.setProofHash(this.buildProofHash());
+  updateStateInfo(updatedChildLabel = null) {
+    if (!LIGHTWEIGHT) {
+      this.setProofHash(this.buildProofHash(updatedChildLabel));
+    }
     this.setTreeHeight(this.computeTreeHeight());
     this.setTreeSize(this.computeTreeSize());
     this.setTreeBytes(this.computeTreeBytes());
diff --git a/db/state-util.js b/db/state-util.js
index 3c22f7546..b41be16a8 100644
--- a/db/state-util.js
+++ b/db/state-util.js
@@ -14,7 +14,6 @@ const {
   ShardingProperties,
   STATE_LABEL_LENGTH_LIMIT,
 } = require('../common/constants');
-const Functions = require('./functions');
 
 function isEmptyNode(node) {
   return node.getIsLeaf() && node.getValue() === null;
@@ -612,48 +611,69 @@ function equalStateTrees(node1, node2) {
   return true;
 }
 
-function setProofHashForStateTree(stateTree) {
+function updateStateInfoForAllRootPathsRecursive(
+    curNode, needToUpdate, updatedChildLabel = null) {
   let numAffectedNodes = 0;
-  if (!stateTree.getIsLeaf()) {
-    for (const node of stateTree.getChildNodes()) {
-      numAffectedNodes += setProofHashForStateTree(node);
+  const curLabel = curNode.getLabel();
+  const parentNodes = curNode.getParentNodes();
+  const isEmpty = isEmptyNode(curNode);
+  if (isEmpty) {
+    for (const parent of parentNodes) {
+      parent.deleteChild(curLabel);
+      numAffectedNodes++;
     }
+  } else if (needToUpdate) {  // Update state info of only parents.
+    curNode.updateStateInfo(updatedChildLabel);
+    numAffectedNodes++;
   }
-  stateTree.updateProofHashAndStateInfo();
-  numAffectedNodes++;
-
-  return numAffectedNodes;
-}
-
-function updateProofHashForAllRootPathsRecursive(node) {
-  let numAffectedNodes = 0;
-  node.updateProofHashAndStateInfo();
-  numAffectedNodes++;
-  for (const parent of node.getParentNodes()) {
-    numAffectedNodes += updateProofHashForAllRootPathsRecursive(parent);
+  for (const parent of parentNodes) {
+    numAffectedNodes +=
+        updateStateInfoForAllRootPathsRecursive(parent, true, isEmpty ? null : curLabel);
   }
   return numAffectedNodes;
 }
 
-function updateProofHashForAllRootPaths(fullPath, root) {
-  const LOG_HEADER = 'updateProofHashForAllRootPaths';
+function updateStateInfoForAllRootPaths(fullPath, root) {
+  const LOG_HEADER = 'updateStateInfoForAllRootPaths';
+
+  if (fullPath.length === 0) {
+    // No parents to update.
+    return 0;
+  }
   if (!root) {
-    logger.error(`[${LOG_HEADER}] Trying to update proof hash for invalid root: ${root}.`);
+    logger.error(`[${LOG_HEADER}] Updating state info for invalid root: ${root} ` +
+    `at: ${new Error().stack}.`);
     return 0;
   }
-  let node = root;
+  let curNode = root;
+  let needToUpdate = false;
   for (let i = 0; i < fullPath.length; i++) {
-    const label = fullPath[i];
-    const child = node.getChild(label);
+    const childLabel = fullPath[i];
+    const child = curNode.getChild(childLabel);
     if (child === null) {
-      logger.info(
-          `[${LOG_HEADER}] Trying to update proof hash for non-existing path: ` +
-          `${CommonUtil.formatPath(fullPath.slice(0, i + 1))}.`);
+      logger.debug(
+          `[${LOG_HEADER}] Updating state info for non-existing path: ` +
+          `${CommonUtil.formatPath(fullPath.slice(0, i + 1))} ` +
+          `at: ${new Error().stack}.`);
+      needToUpdate = true;
       break;
     }
-    node = child;
+    curNode = child;
+  }
+  return updateStateInfoForAllRootPathsRecursive(curNode, needToUpdate, null);
+}
+
+function updateStateInfoForStateTree(stateTree) {
+  let numAffectedNodes = 0;
+  if (!stateTree.getIsLeaf()) {
+    for (const node of stateTree.getChildNodes()) {
+      numAffectedNodes += updateStateInfoForStateTree(node);
+    }
   }
-  return updateProofHashForAllRootPathsRecursive(node);
+  stateTree.updateStateInfo();
+  numAffectedNodes++;
+
+  return numAffectedNodes;
 }
 
 function verifyProofHashForStateTree(stateTree) {
@@ -670,6 +690,26 @@ function verifyProofHashForStateTree(stateTree) {
   return true;
 }
 
+function getProofOfStatePathRecursive(node, fullPath, labelIndex) {
+  if (labelIndex > fullPath.length - 1) {
+    return node.getProofOfState();
+  }
+  const childLabel = fullPath[labelIndex];
+  if (!node.hasChild(childLabel)) {
+    return null;
+  }
+  const child = node.getChild(childLabel);
+  const childProof = getProofOfStatePathRecursive(child, fullPath, labelIndex + 1);
+  if (childProof === null) {
+    return null;
+  }
+  return node.getProofOfState(childLabel, childProof);
+}
+
+function getProofOfStatePath(root, fullPath) {
+  return getProofOfStatePathRecursive(root, fullPath, 0);
+}
+
 module.exports = {
   isEmptyNode,
   hasShardConfig,
@@ -702,7 +742,8 @@ module.exports = {
   deleteStateTreeVersion,
   makeCopyOfStateTree,
   equalStateTrees,
-  setProofHashForStateTree,
-  updateProofHashForAllRootPaths,
-  verifyProofHashForStateTree
+  updateStateInfoForAllRootPaths,
+  updateStateInfoForStateTree,
+  verifyProofHashForStateTree,
+  getProofOfStatePath,
 };
diff --git a/deploy_blockchain_genesis_gcp.sh b/deploy_blockchain_genesis_gcp.sh
index f5ed9d79c..61e6bc07a 100644
--- a/deploy_blockchain_genesis_gcp.sh
+++ b/deploy_blockchain_genesis_gcp.sh
@@ -1,8 +1,8 @@
-#!/bin/sh
+#!/bin/bash
 
 if [[ "$#" -lt 3 ]]; then
-    echo "Usage: sh deploy_blockchain_genesis_gcp.sh [dev|staging|spring|summer] <GCP Username> <# of Shards> [--setup]"
-    echo "Example: sh deploy_blockchain_genesis_gcp.sh dev lia 0 --setup"
+    echo "Usage: bash deploy_blockchain_genesis_gcp.sh [dev|staging|spring|summer] <GCP Username> <# of Shards> [--setup]"
+    echo "Example: bash deploy_blockchain_genesis_gcp.sh dev lia 0 --setup"
     exit
 fi
 
@@ -39,8 +39,8 @@ then
     [[ "$0" = "$BASH_SOURCE" ]] && exit 1 || return 1 # handle exits from shell or function but don't exit interactive shell
 fi
 
-FILES_FOR_TRACKER="blockchain/ client/ common/ consensus/ db/ genesis-configs/ logger/ tracker-server/ package.json setup_blockchain_ubuntu.sh start_tracker_genesis_gcp.sh"
-FILES_FOR_NODE="blockchain/ client/ common/ consensus/ db/ json_rpc/ genesis-configs/ logger/ node/ tx-pool/ p2p/ package.json setup_blockchain_ubuntu.sh start_node_genesis_gcp.sh"
+FILES_FOR_TRACKER="blockchain/ client/ common/ consensus/ db/ genesis-configs/ logger/ tracker-server/ package.json setup_blockchain_ubuntu.sh start_tracker_genesis_gcp.sh start_tracker_incremental_gcp.sh restart_tracker_gcp.sh"
+FILES_FOR_NODE="blockchain/ client/ common/ consensus/ db/ json_rpc/ genesis-configs/ logger/ node/ tx-pool/ p2p/ package.json setup_blockchain_ubuntu.sh start_node_genesis_gcp.sh start_node_incremental_gcp.sh restart_node_gcp.sh"
 
 TRACKER_TARGET_ADDR="${GCP_USER}@${SEASON}-tracker-taiwan"
 NODE_0_TARGET_ADDR="${GCP_USER}@${SEASON}-node-0-taiwan"
diff --git a/deploy_blockchain_incremental_gcp.sh b/deploy_blockchain_incremental_gcp.sh
index 37668edf1..13030da02 100644
--- a/deploy_blockchain_incremental_gcp.sh
+++ b/deploy_blockchain_incremental_gcp.sh
@@ -1,8 +1,8 @@
-#!/bin/sh
+#!/bin/bash
 
 if [[ "$#" -lt 5 ]] || [[ "$#" -gt 6 ]]; then
-    printf "Usage: sh deploy_blockchain_incremental_gcp.sh [dev|staging|spring|summer] <GCP Username> <# of Shards> [fast|full] [canary|full] [--setup]\n"
-    printf "Example: sh deploy_blockchain_incremental_gcp.sh dev lia 0 fast canary --setup\n"
+    printf "Usage: bash deploy_blockchain_incremental_gcp.sh [dev|staging|spring|summer] <GCP Username> <# of Shards> [fast|full] [canary|full] [--setup]\n"
+    printf "Example: bash deploy_blockchain_incremental_gcp.sh dev lia 0 fast canary --setup\n"
     exit
 fi
 
@@ -53,8 +53,8 @@ if [[ ! $REPLY =~ ^[Yy]$ ]]; then
     [[ "$0" = "$BASH_SOURCE" ]] && exit 1 || return 1 # handle exits from shell or function but don't exit interactive shell
 fi
 
-FILES_FOR_TRACKER="blockchain/ client/ common/ consensus/ db/ genesis-configs/ logger/ tracker-server/ package.json setup_blockchain_ubuntu.sh start_tracker_incremental_gcp.sh"
-FILES_FOR_NODE="blockchain/ client/ common/ consensus/ db/ json_rpc/ genesis-configs/ logger/ node/ tx-pool/ p2p/ package.json setup_blockchain_ubuntu.sh start_node_incremental_gcp.sh"
+FILES_FOR_TRACKER="blockchain/ client/ common/ consensus/ db/ genesis-configs/ logger/ tracker-server/ package.json setup_blockchain_ubuntu.sh start_tracker_genesis_gcp.sh start_tracker_incremental_gcp.sh restart_tracker_gcp.sh"
+FILES_FOR_NODE="blockchain/ client/ common/ consensus/ db/ json_rpc/ genesis-configs/ logger/ node/ tx-pool/ p2p/ package.json setup_blockchain_ubuntu.sh start_node_genesis_gcp.sh start_node_incremental_gcp.sh restart_node_gcp.sh"
 
 NUM_PARENT_NODES=5
 NUM_SHARD_NODES=3
diff --git a/deploy_monitoring_gcp.sh b/deploy_monitoring_gcp.sh
index 8365f27c8..6ac0eb47a 100644
--- a/deploy_monitoring_gcp.sh
+++ b/deploy_monitoring_gcp.sh
@@ -1,8 +1,8 @@
-#!/bin/sh
+#!/bin/bash
 
 if [[ "$#" -lt 2 ]]; then
-    echo "Usage: sh deploy_monitoring_gcp.sh [dev|staging|spring|summer] <GCP Username>"
-    echo "Example: sh deploy_monitoring_gcp.sh dev seo"
+    echo "Usage: bash deploy_monitoring_gcp.sh [dev|staging|spring|summer] <GCP Username>"
+    echo "Example: bash deploy_monitoring_gcp.sh dev seo"
     exit
 fi
 
diff --git a/genesis-configs/afan-shard/genesis_params.json b/genesis-configs/afan-shard/genesis_params.json
index 9b1a2302b..f82d630d2 100644
--- a/genesis-configs/afan-shard/genesis_params.json
+++ b/genesis-configs/afan-shard/genesis_params.json
@@ -2,12 +2,9 @@
   "blockchain": {
     "TRANSACTION_POOL_TIMEOUT_MS": 3600000,
     "TRANSACTION_TRACKER_TIMEOUT_MS": 86400000,
-    "NETWORK_ID": "Testnet",
+    "NETWORK_ID": 0,
+    "CHAIN_ID": 0,
     "HOSTING_ENV": "local",
-    "COMCOM_HOST_INTERNAL_IP_MAP": {
-      "aincom1": "192.168.1.13",
-      "aincom2": "192.168.1.14"
-    },
     "TRACKER_WS_ADDR": "ws://localhost:6000",
     "MAX_SHARD_REPORT": 100,
     "REST_FUNCTION_CALL_TIMEOUT_MS": 10000
@@ -23,13 +20,12 @@
   },
   "network": {
     "P2P_MESSAGE_TIMEOUT_MS": 600000,
-    "MAX_OUTBOUND_LIMIT": 2,
-    "MAX_INBOUND_LIMIT": 3,
+    "MAX_NUM_PEER_CANDIDATES_AT_ONCE": 2,
     "DEFAULT_MAX_OUTBOUND": 2,
     "DEFAULT_MAX_INBOUND": 3
   },
   "resource": {
-    "TREE_HEIGHT_LIMIT": 20,
+    "STATE_TREE_HEIGHT_LIMIT": 30,
     "STATE_TREE_BYTES_LIMIT": 5000000000,
     "STATE_LABEL_LENGTH_LIMIT": 150,
     "TX_BYTES_LIMIT": 10000,
diff --git a/genesis-configs/afan-shard/genesis_token.json b/genesis-configs/afan-shard/genesis_token.json
index 8172e1ba6..098daaa09 100644
--- a/genesis-configs/afan-shard/genesis_token.json
+++ b/genesis-configs/afan-shard/genesis_token.json
@@ -1,5 +1,18 @@
 {
   "name": "Fancoin",
   "symbol": "FANCO",
-  "total_supply": 100000000000
+  "total_supply": 100000000000,
+  "bridge": {
+    "AIN": {
+      "0": {
+        "network_id": 1,
+        "token_pool": "0xBBB2219cD5eACc54Ce95deF7a67dDe71C8241891",
+        "min_checkout_per_request": 1000,
+        "max_checkout_per_request": 10000,
+        "max_checkout_per_day": 1000000,
+        "token_exchange_rate": 10,
+        "token_exchange_scheme": "FIXED"
+      }
+    }
+  }
 }
diff --git a/genesis-configs/base/genesis_functions.json b/genesis-configs/base/genesis_functions.json
index 1f2433eb2..a049e96fe 100644
--- a/genesis-configs/base/genesis_functions.json
+++ b/genesis-configs/base/genesis_functions.json
@@ -25,11 +25,41 @@
       }
     }
   },
+  "checkout": {
+    "requests": {
+      "$user_addr": {
+        "$checkout_id": {
+          ".function": {
+            "_openCheckout": {
+              "function_type": "NATIVE",
+              "function_id": "_openCheckout"
+            }
+          }
+        }
+      }
+    },
+    "history": {
+      "$user_addr": {
+        "$checkout_id": {
+          ".function": {
+            "_closeCheckout": {
+              "function_type": "NATIVE",
+              "function_id": "_closeCheckout"
+            }
+          }
+        }
+      }
+    }
+  },
   "consensus": {
     "number": {
       "$number": {
         "propose": {
           ".function": {
+            "_handleOffenses": {
+              "function_type": "NATIVE",
+              "function_id": "_handleOffenses"
+            },
             "_distributeFee": {
               "function_type": "NATIVE",
               "function_id": "_distributeFee"
@@ -68,9 +98,21 @@
     }
   },
   "gas_fee": {
+    "claim": {
+      "$user_addr": {
+        "$record_id": {
+          ".function": {
+            "_claimReward": {
+              "function_type": "NATIVE",
+              "function_id": "_claimReward"
+            }
+          }
+        }
+      }
+    },
     "collect": {
-      "$from": {
-        "$block_number": {
+      "$block_number": {
+        "$from": {
           "$tx_hash": {
             ".function": {
               "_collectFee": {
diff --git a/genesis-configs/base/genesis_params.json b/genesis-configs/base/genesis_params.json
index b2beb5682..f5b27c533 100644
--- a/genesis-configs/base/genesis_params.json
+++ b/genesis-configs/base/genesis_params.json
@@ -2,12 +2,9 @@
   "blockchain": {
     "TRANSACTION_POOL_TIMEOUT_MS": 3600000,
     "TRANSACTION_TRACKER_TIMEOUT_MS": 86400000,
-    "NETWORK_ID": "Testnet",
+    "NETWORK_ID": 0,
+    "CHAIN_ID": 0,
     "HOSTING_ENV": "local",
-    "COMCOM_HOST_INTERNAL_IP_MAP": {
-      "aincom1": "192.168.1.13",
-      "aincom2": "192.168.1.14"
-    },
     "TRACKER_WS_ADDR": "ws://localhost:5000",
     "MAX_SHARD_REPORT": 100,
     "REST_FUNCTION_CALL_TIMEOUT_MS": 10000
@@ -23,13 +20,12 @@
   },
   "network": {
     "P2P_MESSAGE_TIMEOUT_MS": 600000,
-    "MAX_OUTBOUND_LIMIT": 2,
-    "MAX_INBOUND_LIMIT": 3,
+    "MAX_NUM_PEER_CANDIDATES_AT_ONCE": 2,
     "DEFAULT_MAX_OUTBOUND": 2,
     "DEFAULT_MAX_INBOUND": 3
   },
   "resource": {
-    "TREE_HEIGHT_LIMIT": 20,
+    "STATE_TREE_HEIGHT_LIMIT": 30,
     "STATE_TREE_BYTES_LIMIT": 5000000000,
     "STATE_LABEL_LENGTH_LIMIT": 150,
     "TX_BYTES_LIMIT": 10000,
diff --git a/genesis-configs/base/genesis_rules.json b/genesis-configs/base/genesis_rules.json
index b620677a4..3aa52c6bd 100644
--- a/genesis-configs/base/genesis_rules.json
+++ b/genesis-configs/base/genesis_rules.json
@@ -31,7 +31,44 @@
       }
     }
   },
+  "checkout": {
+    "history": {
+      "$user_addr": {
+        "$checkout_id": {
+          ".rule": {
+            "write": "data === null && util.validateCheckoutHistoryData($user_addr, $checkout_id, newData, getValue) && auth.addr === util.getTokenPoolAddr(newData.request.type, newData.request.token_id, getValue)"
+          },
+          "refund": {
+            ".rule": {
+              "write": "data === null && util.isString(newData) && (auth.fid === '_closeCheckout' || auth.addr === util.getTokenPoolAddrFromHistoryData($user_addr, $checkout_id, getValue))"
+            }
+          }
+        }
+      }
+    },
+    "requests": {
+      "$user_addr": {
+        "$checkout_id": {
+          ".rule": {
+            "write": "(auth.fid === '_closeCheckout' && newData === null) || (data === null && auth.addr === $user_addr && util.validateCheckoutRequestData(newData, getValue))"
+          }
+        }
+      }
+    },
+    "stats" : {
+      ".rule": {
+        "write": "auth.fid === '_openCheckout' || auth.fid === '_closeCheckout'"
+      }
+    }
+  },
   "consensus": {
+    "offense_records": {
+      "$user_addr": {
+        ".rule": {
+          "write": "auth.fid === '_handleOffenses'"
+        }
+      }
+    },
     "number": {
       "$number": {
         ".rule": {
@@ -39,18 +76,27 @@
         },
         "propose": {
           ".rule": {
-            "write": "util.isDict(newData) && newData.proposer === auth.addr && Number($number) === newData.number && getValue('/consensus/whitelist/' + auth.addr) === true && (lastBlockNumber < 1 || (getValue('/service_accounts/staking/consensus/' + auth.addr + '|0/balance') >= util.getMinStakeAmount() && getValue('/service_accounts/staking/consensus/' + auth.addr + '|0/balance') <= util.getMaxStakeAmount())) && util.isNumber(newData.gas_cost_total) && (newData.gas_cost_total === 0 || newData.gas_cost_total === getValue('/service_accounts/gas_fee/gas_fee/' + $number + '/balance'))"
+            "write": "util.isDict(newData) && newData.proposer === auth.addr && Number($number) === newData.number && getValue('/consensus/whitelist/' + auth.addr) === true && (lastBlockNumber < 1 || (getValue('/service_accounts/staking/consensus/' + auth.addr + '|0/balance') >= util.getMinStakeAmount() && getValue('/service_accounts/staking/consensus/' + auth.addr + '|0/balance') <= util.getMaxStakeAmount())) && util.isNumber(newData.gas_cost_total)"
           }
         },
-        "vote": {
-          "$user_addr": {
-            ".rule": {
-              "write": "auth.addr === $user_addr && util.isDict(newData) && util.isString(newData.block_hash) && util.isNumber(newData.stake) && (lastBlockNumber < 1 || util.getConsensusStakeBalance(auth.addr, getValue) === newData.stake)"
+        "$block_hash": {
+          "vote": {
+            "$user_addr": {
+              ".rule": {
+                "write": "auth.addr === $user_addr && data === null && util.validateConsensusVoteData(newData, auth.addr, $block_hash, lastBlockNumber, getValue) === true"
+              }
             }
           }
         }
       }
     },
+    "rewards": {
+      "$user_addr": {
+        ".rule": {
+          "write": "auth.fid === '_distributeFee' || auth.fid === '_claimReward'"
+        }
+      }
+    },
     "whitelist": {
       "$user_addr": {
         ".rule": {
@@ -97,12 +143,21 @@
     }
   },
   "gas_fee": {
+    "claim": {
+      "$user_addr": {
+        "$record_id": {
+          ".rule": {
+            "write": "auth.addr === $user_addr && util.validateClaimRewardData(auth.addr, newData, getValue) === true"
+          }
+        }
+      }
+    },
     "collect": {
-      "$from": {
-        "$block_number": {
+      "$block_number": {
+        "$from": {
           "$tx_hash": {
             ".rule": {
-              "write": "(auth.addr === $from || (util.isServAcntName($from) && util.isBillingUser($from, auth.addr, getValue) === true)) && data === null && util.isDict(newData) && util.isNumber(newData.amount) && newData.amount <= util.getBalance($from, getValue)"
+              "write": "(auth.addr === $from || (util.isServAcntName($from) && util.isBillingUser($from, auth.addr, getValue) === true)) && util.validateCollectFeeData(data, newData, $from, getValue)"
             }
           }
         }
@@ -198,7 +253,7 @@
         "$staking_key": {
           "expire_at": {
             ".rule": {
-              "write": "auth.fid === '_stake'"
+              "write": "auth.fid === '_stake' || auth.fid === '_handleOffenses'"
             }
           },
           "stake": {
@@ -239,7 +294,7 @@
         "$key": {
           "value": {
             ".rule": {
-              "write": "(auth.addr === $from || auth.fid === '_stake' || auth.fid === '_unstake' || auth.fid === '_pay' || auth.fid === '_claim' || auth.fid === '_hold' || auth.fid === '_release' || auth.fid === '_collectFee' || auth.fid === '_distributeFee') && !getValue('transfer/' + $from + '/' + $to + '/' + $key) && (util.isServAcntName($from) || util.isCksumAddr($from)) && (util.isServAcntName($to) || util.isCksumAddr($to)) && $from !== $to && util.isNumber(newData) && util.getBalance($from, getValue) >= newData"
+              "write": "(auth.addr === $from || auth.fid === '_stake' || auth.fid === '_unstake' || auth.fid === '_pay' || auth.fid === '_claim' || auth.fid === '_hold' || auth.fid === '_release' || auth.fid === '_collectFee' || auth.fid === '_claimReward' || auth.fid === '_openCheckout' || auth.fid === '_closeCheckout') && !getValue('transfer/' + $from + '/' + $to + '/' + $key) && (util.isServAcntName($from) || util.isCksumAddr($from)) && (util.isServAcntName($to) || util.isCksumAddr($to)) && $from !== $to && util.isNumber(newData) && util.getBalance($from, getValue) >= newData"
             }
           },
           "result": {
diff --git a/genesis-configs/base/genesis_token.json b/genesis-configs/base/genesis_token.json
index 671e18cce..2c48937c0 100644
--- a/genesis-configs/base/genesis_token.json
+++ b/genesis-configs/base/genesis_token.json
@@ -1,5 +1,18 @@
 {
   "name": "AI Network",
   "symbol": "AIN",
-  "total_supply": 700000000
+  "total_supply": 700000000,
+  "bridge": {
+    "ETH": {
+      "0xB16c0C80a81f73204d454426fC413CAe455525A7": {
+        "network_id": 3,
+        "token_pool": "0x20ADd3d38405ebA6338CB9e57a0510DEB8f8e000",
+        "min_checkout_per_request": 10,
+        "max_checkout_per_request": 10000,
+        "max_checkout_per_day": 1000000,
+        "token_exchange_rate": 1,
+        "token_exchange_scheme": "FIXED"
+      }
+    }
+  }
 }
diff --git a/genesis-configs/he-shard/genesis_accounts.json b/genesis-configs/he-shard/genesis_accounts.json
new file mode 100644
index 000000000..4e01358e8
--- /dev/null
+++ b/genesis-configs/he-shard/genesis_accounts.json
@@ -0,0 +1,61 @@
+{
+  "owner": {
+    "address": "0xBBB2219cD5eACc54Ce95deF7a67dDe71C8241891",
+    "private_key": "6204d4e083dd09c7b084e5923c5d664d2e1f3ce8440f90a773638f30c61d9c40",
+    "public_key": "e466afe2938a4a804de86b3abd81403a982d33a7341649afccdb83e8f79c51a27516cdae3baddf3bce12992679ed2d793e65285dad38325a4d8c11ac83f378c1"
+  },
+  "timestamp": 1571819318272,
+  "shares": 1000000,
+  "others": [
+    {
+      "address": "0x00Ba0Cb2B1157882963024E0CF837E773d11535d",
+      "private_key": "d8f77aa2afe2580a858a8cc97b6056e10f888c6fd07ebb58755d8422b03da816",
+      "public_key": "6ec50cb2072f52005e68a6a21190286024b8fdef7adf8fb1e17b91e33ce8566c6a30cbbc7b18a7065cc096a18e8ce41257467847786679c87cfaf34a1dbbe8ac"
+    },
+    {
+      "address": "0x01B6B108bE3FEE00d3661777053175421D806Ea6",
+      "private_key": "a3409e22bc14a3d0e73697df25617b3f2eaae9b5eade77615a32abc0ad5ee0df",
+      "public_key": "85c296431d012cd32db75e215a41b48b9842ae71654fa2e6ad4eb95ab98e9e2bccc3e02b76d39dad3ffbc8e7a18f1c5f473289cdd33fd88f7127547c8a56c24c"
+    },
+    {
+      "address": "0x02B3a185C6a9DCd643255329d3eB8603E3D0d743",
+      "private_key": "c4611582dbb5319f08ba0907af6430a79e02b87b112aa4039d43e8765384f568",
+      "public_key": "1e6442a16d01836e121241d1307470eb8efd8a5628f80dd9816078f261d87b812c5128b80abb72ff8144386ebff10a19adbaffd93c48941acc587e7992e86579"
+    },
+    {
+      "address": "0x03B8986541c95af87b69F2b61Ce65ea5b4d5910f",
+      "private_key": "f645009004b11b7ac35cf13ef46e90caed5db3e45c266d9eb6a2356b7c20c97b",
+      "public_key": "c26e2dadece06375329cd6695b147ae7faccb375ff3a96b989598635f2833d70b775ba7f1bfc43ae6ba3fae8e3f3825a36c76d76948a1e8e8130d22da0d2719c"
+    },
+    {
+      "address": "0x04B8b3c7adeCC195F11276E9153E311A555FC2Db",
+      "private_key": "754cf329746eec09c83084d113437e48e1ebd00d10853844c0d109cd5cb7dc35",
+      "public_key": "28396f3d4c112923413bb2b9bfe65c216903c08034ba599bdbd4ead6aa08dbe62a4fad65bce1ffc1724056e530468cfd5c38bfe40f15a59391addad6a5df9856"
+    },
+    {
+      "address": "0x05B65a1351603198af0d1B21CE9a7E4E34040aD4",
+      "private_key": "a9d3f4658fd23dc0b6ad5778f5522352d154406536c7db7b9c9be3893f6f85b6",
+      "public_key": "653f64f3f2dfc1a5d870fd79d90dfc3bba55076194bae7b1882f8e4ff5d4755f2906ef49a9fb7a5c4303a895a6ced090603d8a4a7b5044d25701538a7a7d6b50"
+    },
+    {
+      "address": "0x06B91344A925531D7Beb375eeD8ca4804C1E7dd7",
+      "private_key": "96052f7d3fc12c429afcee36f2c11eeb87094426735bff1fa18fe8c8c691444b",
+      "public_key": "30191fcdfe246068752cd3f57508bf1aa4a58b576a848b0e4dd8c5b5003833a7f0af5fb673560e78ed988ea987872f00a7367c43d53322250e435c898da92d65"
+    },
+    {
+      "address": "0x07B09E39A13beb5df9A58b4d3a4070ccB73B2A30",
+      "private_key": "642bc7106a07cdd797700533e6bf9b7c060eb73b033b2fd0fb7c39c14d1ef8c5",
+      "public_key": "1427b6f8d2c2c397f0f389c3c5f5010e539861f0ce307579c7c8c857547a92aea8e5fdac38c2cee945246c4a9b386a39feb2514ccd29436d5d2bf5af65ccea28"
+    },
+    {
+      "address": "0x08Bfea90424E93cd9aB1cE80A1E4f46f452C8ae9",
+      "private_key": "e70d49408f10df58d1d9587a1a2f9a8f6e8e0b54dc9c555178291190872b86db",
+      "public_key": "a16c7fee61380ff1ce8538394d3acf768f6090ec655c626ebb865410927ae3102bd43a4fcf0fdf80318aba786a07c11052366c7d5fcf440bb25dcc629c0aba53"
+    },
+    {
+      "address": "0x09BAec4d86C2b376bF85Ef91191bEd401d33634B",
+      "private_key": "e5cf600fbd1bdf5f5cdddfe5b93385d7f8188c9cbd0dbd7533c199e341e28930",
+      "public_key": "7b8ae793124d6c898d9841b6e6edd49c2c01e681f3f86a5bb7a697892d7d804ee3b993b449885610fb3bef839e4fe720ea28e613cec30f60c9f3033b3c268f5e"
+    }
+  ]
+}
diff --git a/genesis-configs/he-shard/genesis_params.json b/genesis-configs/he-shard/genesis_params.json
new file mode 100644
index 000000000..d3ac1c70d
--- /dev/null
+++ b/genesis-configs/he-shard/genesis_params.json
@@ -0,0 +1,38 @@
+{
+  "blockchain": {
+    "TRANSACTION_POOL_TIMEOUT_MS": 3600000,
+    "TRANSACTION_TRACKER_TIMEOUT_MS": 86400000,
+    "NETWORK_ID": 0,
+    "CHAIN_ID": 0,
+    "HOSTING_ENV": "local",
+    "TRACKER_WS_ADDR": "ws://localhost:6000",
+    "MAX_SHARD_REPORT": 100,
+    "REST_FUNCTION_CALL_TIMEOUT_MS": 10000
+  },
+  "consensus": {
+    "MIN_STAKE_PER_VALIDATOR": 100000,
+    "MAX_STAKE_PER_VALIDATOR": 100000,
+    "MIN_NUM_VALIDATORS": 3,
+    "MAX_NUM_VALIDATORS": 9,
+    "EPOCH_MS": 3000,
+    "GENESIS_WHITELIST": {},
+    "GENESIS_VALIDATORS": {}
+  },
+  "network": {
+    "P2P_MESSAGE_TIMEOUT_MS": 600000,
+    "DEFAULT_MAX_OUTBOUND": 2,
+    "DEFAULT_MAX_INBOUND": 3
+  },
+  "resource": {
+    "STATE_TREE_HEIGHT_LIMIT": 30,
+    "STATE_TREE_BYTES_LIMIT": 5000000000,
+    "STATE_LABEL_LENGTH_LIMIT": 150,
+    "TX_BYTES_LIMIT": 10000,
+    "BATCH_TX_LIST_SIZE_LIMIT": 50,
+    "TX_POOL_SIZE_LIMIT": 1000,
+    "TX_POOL_SIZE_LIMIT_PER_ACCOUNT": 100,
+    "BANDWIDTH_BUDGET_PER_BLOCK": 10000,
+    "MIN_STAKING_FOR_APP_TX": 0,
+    "MIN_BALANCE_FOR_SERVICE_TX": 0
+  }
+}
diff --git a/genesis-configs/he-shard/genesis_sharding.json b/genesis-configs/he-shard/genesis_sharding.json
new file mode 100644
index 000000000..3e5fc87fb
--- /dev/null
+++ b/genesis-configs/he-shard/genesis_sharding.json
@@ -0,0 +1,8 @@
+{
+  "sharding_protocol": "POA",
+  "sharding_path": "/apps/he_health_care",
+  "parent_chain_poc": "http://127.0.0.1:8081",
+  "reporting_period": 5,
+  "token_exchange_scheme": "FIXED",
+  "token_exchange_rate": 10
+}
diff --git a/genesis-configs/he-shard/genesis_token.json b/genesis-configs/he-shard/genesis_token.json
new file mode 100644
index 000000000..6e47a259e
--- /dev/null
+++ b/genesis-configs/he-shard/genesis_token.json
@@ -0,0 +1,18 @@
+{
+  "name": "Hecoin",
+  "symbol": "HECO",
+  "total_supply": 100000000000,
+  "bridge": {
+    "AIN": {
+      "0": {
+        "network_id": 1,
+        "token_pool": "0xBBB2219cD5eACc54Ce95deF7a67dDe71C8241891",
+        "min_checkout_per_request": 1000,
+        "max_checkout_per_request": 10000,
+        "max_checkout_per_day": 1000000,
+        "token_exchange_rate": 10,
+        "token_exchange_scheme": "FIXED"
+      }
+    }
+  }
+}
diff --git a/genesis-configs/sim-shard/genesis_params.json b/genesis-configs/sim-shard/genesis_params.json
index 8cb3cf5c2..98b2d7ef2 100644
--- a/genesis-configs/sim-shard/genesis_params.json
+++ b/genesis-configs/sim-shard/genesis_params.json
@@ -2,12 +2,9 @@
   "blockchain": {
     "TRANSACTION_POOL_TIMEOUT_MS": 3600000,
     "TRANSACTION_TRACKER_TIMEOUT_MS": 86400000,
-    "NETWORK_ID": "Testnet",
+    "NETWORK_ID": 0,
+    "CHAIN_ID": 0,
     "HOSTING_ENV": "local",
-    "COMCOM_HOST_INTERNAL_IP_MAP": {
-      "aincom1": "192.168.1.13",
-      "aincom2": "192.168.1.14"
-    },
     "TRACKER_WS_ADDR": "ws://localhost:6010",
     "MAX_SHARD_REPORT": 100,
     "REST_FUNCTION_CALL_TIMEOUT_MS": 10000
@@ -23,13 +20,12 @@
   },
   "network": {
     "P2P_MESSAGE_TIMEOUT_MS": 600000,
-    "MAX_OUTBOUND_LIMIT": 2,
-    "MAX_INBOUND_LIMIT": 3,
+    "MAX_NUM_PEER_CANDIDATES_AT_ONCE": 2,
     "DEFAULT_MAX_OUTBOUND": 2,
     "DEFAULT_MAX_INBOUND": 3
   },
   "resource": {
-    "TREE_HEIGHT_LIMIT": 20,
+    "STATE_TREE_HEIGHT_LIMIT": 30,
     "STATE_TREE_BYTES_LIMIT": 5000000000,
     "STATE_LABEL_LENGTH_LIMIT": 150,
     "TX_BYTES_LIMIT": 10000,
diff --git a/genesis-configs/sim-shard/genesis_token.json b/genesis-configs/sim-shard/genesis_token.json
index 5973a2d5c..c97fad34b 100644
--- a/genesis-configs/sim-shard/genesis_token.json
+++ b/genesis-configs/sim-shard/genesis_token.json
@@ -1,5 +1,18 @@
 {
   "name": "ShardCoinB0",
   "symbol": "SHARDCOB0",
-  "total_supply": 100000000000
+  "total_supply": 100000000000,
+  "bridge": {
+    "AIN": {
+      "0": {
+        "network_id": 1,
+        "token_pool": "0xB0B0d133E6a82A982396Fa7E4B4F9eC85d1DFBF4",
+        "min_checkout_per_request": 1000,
+        "max_checkout_per_request": 10000,
+        "max_checkout_per_day": 1000000,
+        "token_exchange_rate": 10,
+        "token_exchange_scheme": "FIXED"
+      }
+    }
+  }
 }
\ No newline at end of file
diff --git a/genesis-configs/testnet/genesis_params.json b/genesis-configs/testnet/genesis_params.json
index 45b3f046f..bd2e4307e 100644
--- a/genesis-configs/testnet/genesis_params.json
+++ b/genesis-configs/testnet/genesis_params.json
@@ -2,12 +2,9 @@
   "blockchain": {
     "TRANSACTION_POOL_TIMEOUT_MS": 3600000,
     "TRANSACTION_TRACKER_TIMEOUT_MS": 86400000,
-    "NETWORK_ID": "Testnet",
+    "NETWORK_ID": 0,
+    "CHAIN_ID": 0,
     "HOSTING_ENV": "gcp",
-    "COMCOM_HOST_INTERNAL_IP_MAP": {
-      "aincom1": "192.168.1.13",
-      "aincom2": "192.168.1.14"
-    },
     "TRACKER_WS_ADDR": "ws://34.80.184.73:5000",
     "MAX_SHARD_REPORT": 100,
     "REST_FUNCTION_CALL_TIMEOUT_MS": 10000
@@ -23,13 +20,12 @@
   },
   "network": {
     "P2P_MESSAGE_TIMEOUT_MS": 600000,
-    "MAX_OUTBOUND_LIMIT": 2,
-    "MAX_INBOUND_LIMIT": 3,
+    "MAX_NUM_PEER_CANDIDATES_AT_ONCE": 2,
     "DEFAULT_MAX_OUTBOUND": 2,
     "DEFAULT_MAX_INBOUND": 3
   },
   "resource": {
-    "TREE_HEIGHT_LIMIT": 20,
+    "STATE_TREE_HEIGHT_LIMIT": 30,
     "STATE_TREE_BYTES_LIMIT": 5000000000,
     "STATE_LABEL_LENGTH_LIMIT": 150,
     "TX_BYTES_LIMIT": 10000,
diff --git a/genesis-configs/testnet/genesis_token.json b/genesis-configs/testnet/genesis_token.json
new file mode 100644
index 000000000..4764fb45b
--- /dev/null
+++ b/genesis-configs/testnet/genesis_token.json
@@ -0,0 +1,18 @@
+{
+  "name": "AI Network",
+  "symbol": "AIN",
+  "total_supply": 700000000,
+  "bridge": {
+    "ETH": {
+      "0x3A810ff7211b40c4fA76205a14efe161615d0385": {
+        "network_id": 1,
+        "token_pool": "0x744Cb74A78Ac6dae46ebdaCa43e38ED60F965B8D",
+        "min_checkout_per_request": 1000,
+        "max_checkout_per_request": 10000,
+        "max_checkout_per_day": 1000000,
+        "token_exchange_rate": 1,
+        "token_exchange_scheme": "FIXED"
+      }
+    }
+  }
+}
diff --git a/integration/afan_dapp.test.js b/integration/afan_dapp.test.js
index b04b735a1..5b4434906 100644
--- a/integration/afan_dapp.test.js
+++ b/integration/afan_dapp.test.js
@@ -7,27 +7,32 @@ const syncRequest = require('sync-request');
 const AfanClient = require('../afan_client');
 const { CHAINS_DIR } = require('../common/constants');
 const CommonUtil = require('../common/common-util');
-const { waitUntilTxFinalized, parseOrLog, setUpApp } = require('../unittest/test-util');
+const {
+  waitUntilTxFinalized,
+  waitUntilNetworkIsReady,
+  parseOrLog,
+  setUpApp
+} = require('../unittest/test-util');
 const PROJECT_ROOT = require('path').dirname(__filename) + '/../';
 const TRACKER_SERVER = PROJECT_ROOT + 'tracker-server/index.js';
 const APP_SERVER = PROJECT_ROOT + 'client/index.js';
 
 const ENV_VARIABLES = [
   {
-    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 0, EPOCH_MS: 1000, DEBUG: false,
-    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 0, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
   },
   {
-    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 1, EPOCH_MS: 1000, DEBUG: false,
-    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 1, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
   },
   {
-    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 2, EPOCH_MS: 1000, DEBUG: false,
-    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 2, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
   },
   {
-    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 3, EPOCH_MS: 1000, DEBUG: false,
-    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 3, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
   },
 ];
 
@@ -103,15 +108,15 @@ describe('DApp Test', async () => {
   before(async () => {
     rimraf.sync(CHAINS_DIR);
     tracker_proc = startServer(TRACKER_SERVER, 'tracker server', { CONSOLE_LOG: false }, true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(3000);
     server1_proc = startServer(APP_SERVER, 'server1', ENV_VARIABLES[0], true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(10000);
     server2_proc = startServer(APP_SERVER, 'server2', ENV_VARIABLES[1], true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(3000);
     server3_proc = startServer(APP_SERVER, 'server3', ENV_VARIABLES[2], true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(3000);
     server4_proc = startServer(APP_SERVER, 'server4', ENV_VARIABLES[3], true);
-    await CommonUtil.sleep(2000);
+    await waitUntilNetworkIsReady(serverList);
   });
 
   after(() => {
diff --git a/integration/blockchain.test.js b/integration/blockchain.test.js
index e9ca3c0d1..65cfe63ed 100644
--- a/integration/blockchain.test.js
+++ b/integration/blockchain.test.js
@@ -19,38 +19,39 @@ const {
 const { ConsensusConsts } = require('../consensus/constants');
 const CommonUtil = require('../common/common-util');
 const NUMBER_OF_TRANSACTIONS_SENT_BEFORE_TEST = 5;
-const MAX_PROMISE_STACK_DEPTH = 10;
 const MAX_CHAIN_LENGTH_DIFF = 5;
 const {
   waitUntilTxFinalized,
   waitForNewBlocks,
+  waitUntilNetworkIsReady,
   waitUntilNodeSyncs,
   parseOrLog,
   setUpApp
 } = require('../unittest/test-util');
+const { Block } = require('../blockchain/block');
 
 const ENV_VARIABLES = [
   {
-    ACCOUNT_INDEX: 0, MIN_NUM_VALIDATORS: 4, EPOCH_MS: 1000, DEBUG: false,
-    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    ACCOUNT_INDEX: 0, MIN_NUM_VALIDATORS: 4, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
     ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
     ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
   },
   {
-    ACCOUNT_INDEX: 1, MIN_NUM_VALIDATORS: 4, EPOCH_MS: 1000, DEBUG: false,
-    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    ACCOUNT_INDEX: 1, MIN_NUM_VALIDATORS: 4, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
     ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
     ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
   },
   {
-    ACCOUNT_INDEX: 2, MIN_NUM_VALIDATORS: 4, EPOCH_MS: 1000, DEBUG: false,
-    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    ACCOUNT_INDEX: 2, MIN_NUM_VALIDATORS: 4, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
     ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
     ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
   },
   {
-    ACCOUNT_INDEX: 3, MIN_NUM_VALIDATORS: 4, EPOCH_MS: 1000, DEBUG: false,
-    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    ACCOUNT_INDEX: 3, MIN_NUM_VALIDATORS: 4, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
     ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
     ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
   },
@@ -239,15 +240,16 @@ describe('Blockchain Cluster', () => {
     // Start up all servers
     trackerProc = new Process(TRACKER_SERVER, { CONSOLE_LOG: false });
     trackerProc.start(true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(3000);
     for (let i = 0; i < SERVER_PROCS.length; i++) {
       const proc = SERVER_PROCS[i];
       proc.start(true);
-      await CommonUtil.sleep(2000);
+      await CommonUtil.sleep(i === 0 ? 10000 : 3000);
       const address =
           parseOrLog(syncRequest('GET', serverList[i] + '/get_address').body.toString('utf-8')).result;
       nodeAddressList.push(address);
     };
+    await waitUntilNetworkIsReady(serverList);
     jsonRpcClient = jayson.client.http(server2 + JSON_RPC_ENDPOINT);
     promises.push(new Promise((resolve) => {
       jsonRpcClient.request(JSON_RPC_GET_RECENT_BLOCK,
@@ -424,21 +426,6 @@ describe('Blockchain Cluster', () => {
       const hashString = (str) => {
         return '0x' + ainUtil.hashMessage(str).toString('hex');
       }
-      const hashBlock = (block) => {
-        return hashString(stringify({
-          last_hash: block.last_hash,
-          last_votes_hash: block.last_votes_hash,
-          transactions_hash: block.transactions_hash,
-          number: block.number,
-          epoch: block.epoch,
-          state_proof_hash: block.state_proof_hash,
-          timestamp: block.timestamp,
-          proposer: block.proposer,
-          validators: block.validators,
-          gas_amount_total: block.gas_amount_total,
-          gas_cost_total: block.gas_cost_total
-        }));
-      }
       for (let i = 0; i < serverList.length; i++) {
         await sendTransactions(sentOperations);
         const blocks = parseOrLog(syncRequest('POST', serverList[i] + '/json-rpc',
@@ -448,9 +435,9 @@ describe('Blockchain Cluster', () => {
         const len = blocks.length;
         for (let j = 0; j < len; j++) {
           const block = blocks[j];
-          if (block.hash !== hashBlock(block)) {
+          if (block.hash !== Block.hash(block)) {
             assert.fail(`Block hash is incorrect for block ${JSON.stringify(block, null, 2)}` +
-                        `\n(hash: ${hashBlock(block)}, node ${i})`);
+                        `\n(hash: ${Block.hash(block)}, node ${i})`);
           }
           if (block.transactions_hash !== hashString(stringify(block.transactions))) {
             assert.fail(`Transactions or transactions_hash is incorrect for block ${block.hash}`);
@@ -667,6 +654,8 @@ describe('Blockchain Cluster', () => {
     });
   });
 
+  // NOTE(liayoo): Below test is flaky. Uncomment once the problem is fixed.
+  /*
   describe('Restart', () => {
     it('blockchain nodes can be stopped and restarted', async () => {
       SERVER_PROCS[0].kill();
@@ -709,6 +698,7 @@ describe('Blockchain Cluster', () => {
       });
     });
   });
+*/
 
   describe('Protocol versions', () => {
     it('accepts API calls with correct protoVer', () => {
diff --git a/integration/consensus.test.js b/integration/consensus.test.js
index 3f6257c90..af09f6525 100644
--- a/integration/consensus.test.js
+++ b/integration/consensus.test.js
@@ -10,46 +10,58 @@ const APP_SERVER = PROJECT_ROOT + 'client/index.js';
 const syncRequest = require('sync-request');
 const {
   CURRENT_PROTOCOL_VERSION,
+  CONSENSUS_PROTOCOL_VERSION,
   CHAINS_DIR,
   PredefinedDbPaths,
 } = require('../common/constants');
+const {
+  ConsensusMessageTypes,
+  ConsensusConsts,
+  ValidatorOffenseTypes,
+} = require('../consensus/constants');
 const CommonUtil = require('../common/common-util');
-const MAX_ITERATION = 200;
+const PathUtil = require('../common/path-util');
 const {
   waitUntilTxFinalized,
+  waitUntilNetworkIsReady,
   waitForNewBlocks,
   parseOrLog,
   getLastBlock,
 } = require('../unittest/test-util');
+const { Block } = require('../blockchain/block');
+const Functions = require('../db/functions');
+const ConsensusUtil = require('../consensus/consensus-util');
+const { expect } = require('chai');
 
+const MAX_ITERATION = 200;
 const MAX_NUM_VALIDATORS = 4;
 const ENV_VARIABLES = [
   {
-    ACCOUNT_INDEX: 0, MIN_NUM_VALIDATORS: 3, MAX_NUM_VALIDATORS, EPOCH_MS: 1000, DEBUG: false,
+    ACCOUNT_INDEX: 0, MIN_NUM_VALIDATORS: 3, MAX_NUM_VALIDATORS, DEBUG: false,
     CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
     ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
     ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
   },
   {
-    ACCOUNT_INDEX: 1, MIN_NUM_VALIDATORS: 3, MAX_NUM_VALIDATORS, EPOCH_MS: 1000, DEBUG: false,
+    ACCOUNT_INDEX: 1, MIN_NUM_VALIDATORS: 3, MAX_NUM_VALIDATORS, DEBUG: false,
     CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
     ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
     ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
   },
   {
-    ACCOUNT_INDEX: 2, MIN_NUM_VALIDATORS: 3, MAX_NUM_VALIDATORS, EPOCH_MS: 1000, DEBUG: false,
+    ACCOUNT_INDEX: 2, MIN_NUM_VALIDATORS: 3, MAX_NUM_VALIDATORS, DEBUG: false,
     CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
     ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
     ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
   },
   {
-    ACCOUNT_INDEX: 3, MIN_NUM_VALIDATORS: 3, MAX_NUM_VALIDATORS, EPOCH_MS: 1000, DEBUG: false,
+    ACCOUNT_INDEX: 3, MIN_NUM_VALIDATORS: 3, MAX_NUM_VALIDATORS, DEBUG: false,
     CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
     ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
     ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
   },
   {
-    ACCOUNT_INDEX: 4, MIN_NUM_VALIDATORS: 3, MAX_NUM_VALIDATORS, EPOCH_MS: 1000, DEBUG: false,
+    ACCOUNT_INDEX: 4, MIN_NUM_VALIDATORS: 3, MAX_NUM_VALIDATORS, DEBUG: false,
     CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
     ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
     ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
@@ -109,6 +121,9 @@ for (let i = 0; i < ENV_VARIABLES.length; i++) {
 describe('Consensus', () => {
   let trackerProc;
   let jsonRpcClient;
+  let server1Addr;
+  let server2Addr;
+  let server3Addr;
   let server4Addr;
   let server5Addr;
   const nodeAddressList = [];
@@ -120,15 +135,16 @@ describe('Consensus', () => {
     // Start up all servers
     trackerProc = new Process(TRACKER_SERVER, { CONSOLE_LOG: false });
     trackerProc.start(true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(3000);
     for (let i = 0; i < SERVER_PROCS.length; i++) {
       const proc = SERVER_PROCS[i];
       proc.start(true);
-      await CommonUtil.sleep(2000);
+      await CommonUtil.sleep(i === 0 ? 100000 : 3000);
       const address =
           parseOrLog(syncRequest('GET', serverList[i] + '/get_address').body.toString('utf-8')).result;
       nodeAddressList.push(address);
     };
+    await waitUntilNetworkIsReady(serverList);
     jsonRpcClient = jayson.client.http(server2 + JSON_RPC_ENDPOINT);
     promises.push(new Promise((resolve) => {
       jsonRpcClient.request(JSON_RPC_GET_RECENT_BLOCK,
@@ -188,13 +204,13 @@ describe('Consensus', () => {
         iterCount++;
         await CommonUtil.sleep(200);
       }
-      assert.deepEqual(lastBlock.validators[server4Addr][PredefinedDbPaths.PROPOSAL_RIGHT], false);
+      assert.deepEqual(lastBlock.validators[server4Addr][PredefinedDbPaths.CONSENSUS_PROPOSAL_RIGHT], false);
       await waitForNewBlocks(server1, 1);
       const server4Voted = parseOrLog(syncRequest(
         'GET',
-        `${server1}/get_value?ref=/consensus/number/${lastBlock.number}/vote/${server4Addr}`
+        `${server1}/get_value?ref=/consensus/number/${lastBlock.number}/${lastBlock.hash}/vote/${server4Addr}`
       ).body.toString('utf-8')).result;
-      assert.deepEqual(server4Voted[PredefinedDbPaths.STAKE], 100000);
+      assert.deepEqual(server4Voted[PredefinedDbPaths.CONSENSUS_STAKE], 100000);
       // 3. server5 stakes 100000
       const server5StakeRes = parseOrLog(syncRequest('POST', server5 + '/set_value', {json: {
         ref: `/staking/consensus/${server5Addr}/0/stake/${Date.now()}/value`,
@@ -217,14 +233,14 @@ describe('Consensus', () => {
         iterCount++;
         await CommonUtil.sleep(200);
       }
-      assert.deepEqual(lastBlock.validators[server5Addr][PredefinedDbPaths.PROPOSAL_RIGHT], false);
+      assert.deepEqual(lastBlock.validators[server5Addr][PredefinedDbPaths.CONSENSUS_PROPOSAL_RIGHT], false);
       await waitForNewBlocks(server1, 1);
       const votes = parseOrLog(syncRequest(
         'GET',
-        `${server1}/get_value?ref=/consensus/number/${lastBlock.number}/vote`
+        `${server1}/get_value?ref=/consensus/number/${lastBlock.number}/${lastBlock.hash}/vote`
       ).body.toString('utf-8')).result;
       assert.deepEqual(votes[server4Addr], undefined);
-      assert.deepEqual(votes[server5Addr][PredefinedDbPaths.STAKE], 100000);
+      assert.deepEqual(votes[server5Addr][PredefinedDbPaths.CONSENSUS_STAKE], 100000);
     });
 
     it('When more than MAX_NUM_VALIDATORS validators exist, validatators with bigger stakes get prioritized', async () => {
@@ -252,10 +268,10 @@ describe('Consensus', () => {
       await waitForNewBlocks(server1, 1);
       let votes = parseOrLog(syncRequest(
         'GET',
-        `${server1}/get_value?ref=/consensus/number/${lastBlock.number}/vote`
+        `${server1}/get_value?ref=/consensus/number/${lastBlock.number}/${lastBlock.hash}/vote`
       ).body.toString('utf-8')).result;
       assert.deepEqual(votes[server5Addr], undefined);
-      assert.deepEqual(votes[server4Addr][PredefinedDbPaths.STAKE], 100010);
+      assert.deepEqual(votes[server4Addr][PredefinedDbPaths.CONSENSUS_STAKE], 100010);
       // 3. server5 stakes 20 more AIN
       const server5StakeRes = parseOrLog(syncRequest('POST', server5 + '/set_value', {json: {
         ref: `/staking/consensus/${server5Addr}/0/stake/${Date.now()}/value`,
@@ -281,10 +297,270 @@ describe('Consensus', () => {
       await waitForNewBlocks(server1, 1);
       votes = parseOrLog(syncRequest(
         'GET',
-        `${server1}/get_value?ref=/consensus/number/${lastBlock.number}/vote`
+        `${server1}/get_value?ref=/consensus/number/${lastBlock.number}/${lastBlock.hash}/vote`
       ).body.toString('utf-8')).result;
       assert.deepEqual(votes[server4Addr], undefined);
-      assert.deepEqual(votes[server5Addr][PredefinedDbPaths.STAKE], 100020);
+      assert.deepEqual(votes[server5Addr][PredefinedDbPaths.CONSENSUS_STAKE], 100020);
+    });
+  });
+
+  describe('Rewards', () => {
+    it('consensus rewards are updated', async () => {
+      const rewardsBefore = parseOrLog(syncRequest('GET',
+          server2 + `/get_value?ref=/consensus/rewards`).body.toString('utf-8')).result || {};
+      const txWithGasFee = parseOrLog(syncRequest('POST', server1 + '/set_value', {json: {
+        ref: `/transfer/${server1Addr}/${server2Addr}/0/value`,
+        value: 1,
+        gas_price: 1000000
+      }}).body.toString('utf-8')).result;
+      if (!(await waitUntilTxFinalized(serverList, txWithGasFee.tx_hash))) {
+        console.error(`Failed to check finalization of tx.`);
+      }
+      await waitForNewBlocks(server2); // Make sure 1 more block is finalized
+      const rewardsAfter = parseOrLog(syncRequest('GET',
+          server2 + `/get_value?ref=/consensus/rewards`).body.toString('utf-8')).result;
+      const txInfo = parseOrLog(syncRequest('GET',
+          server2 + `/get_transaction?hash=${txWithGasFee.tx_hash}`).body.toString('utf-8')).result;
+      const blockNumber = txInfo.number;
+      const consensusRound = parseOrLog(syncRequest('GET',
+          server2 + `/get_value?ref=/consensus/number/${blockNumber}`).body.toString('utf-8')).result;
+      const proposer = consensusRound.propose.proposer;
+      const blockHash = consensusRound.propose.block_hash;
+      const votes = consensusRound[blockHash].vote;
+      const validators = Object.keys(votes);
+      const gasCostTotal = consensusRound.propose.gas_cost_total;
+      const proposerReward = gasCostTotal / 2;
+      const validatorRewardTotal = gasCostTotal - proposerReward;
+      const totalAtStake = Object.values(votes).reduce((acc, cur) => acc + cur.stake, 0);
+      let rewardSum = 0;
+      validators.forEach((validator, index) => {
+        const validatorStake = votes[validator].stake;
+        let validatorReward = 0;
+        if (index === validators.length - 1) {
+          validatorReward = validatorRewardTotal - rewardSum;
+        } else {
+          validatorReward = validatorRewardTotal * (validatorStake / totalAtStake);
+          rewardSum += validatorReward;
+        }
+        if (validator === proposer) {
+          validatorReward += proposerReward;
+        }
+        assert.deepEqual(_.get(rewardsBefore, `${validator}.unclaimed`, 0) + validatorReward,
+            rewardsAfter[validator].unclaimed);
+        assert.deepEqual(_.get(rewardsBefore, `${validator}.cumulative`, 0) + validatorReward,
+            rewardsAfter[validator].cumulative);
+      });
+      assert.deepEqual(txWithGasFee.result.gas_cost_total, consensusRound.propose.gas_cost_total);
+    });
+
+    it('cannot claim more than unclaimed rewards', async () => {
+      const unclaimed = parseOrLog(syncRequest('GET',
+          server2 + `/get_value?ref=/consensus/rewards/${server1Addr}/unclaimed`).body.toString('utf-8')).result;
+      const claimTx = parseOrLog(syncRequest('POST', server1 + '/set_value', {json: {
+        ref: `/gas_fee/claim/${server1Addr}/0`,
+        value: {
+          amount: unclaimed + 1
+        }
+      }}).body.toString('utf-8')).result;
+      if (!(await waitUntilTxFinalized(serverList, claimTx.tx_hash))) {
+        console.error(`Failed to check finalization of tx.`);
+      }
+      assert.deepEqual(claimTx.result, {
+        "gas_amount_total":{
+          "bandwidth":{
+            "service":1
+          },
+          "state":{
+            "service":0
+          }
+        },
+        "gas_cost_total":0,
+        "error_message":"No write permission on: /gas_fee/claim/0x00ADEc28B6a845a085e03591bE7550dd68673C1C/0",
+        "code":103,
+        "bandwidth_gas_amount":1,
+        "gas_amount_charged":1
+      });
+    });
+
+    it('can claim unclaimed rewards', async () => {
+      const unclaimed = parseOrLog(syncRequest('GET',
+          server2 + `/get_value?ref=/consensus/rewards/${server1Addr}/unclaimed`).body.toString('utf-8')).result;
+      const claimTx = parseOrLog(syncRequest('POST', server1 + '/set_value', {json: {
+        ref: `/gas_fee/claim/${server1Addr}/1`,
+        value: {
+          amount: unclaimed
+        },
+        timestamp: 1629377509815
+      }}).body.toString('utf-8')).result;
+      if (!(await waitUntilTxFinalized(serverList, claimTx.tx_hash))) {
+        console.error(`Failed to check finalization of tx.`);
+      }
+      assert.deepEqual(claimTx.result, {
+        "gas_amount_total": {
+          "bandwidth": {
+            "service": 6
+          },
+          "state": {
+            "service": 2414
+          }
+        },
+        "gas_cost_total": 0,
+        "func_results": {
+          "_claimReward": {
+            "op_results": {
+              "0": {
+                "path": "/transfer/gas_fee|gas_fee|unclaimed/0x00ADEc28B6a845a085e03591bE7550dd68673C1C/1629377509815/value",
+                "result": {
+                  "func_results": {
+                    "_transfer": {
+                      "op_results": {
+                        "0": {
+                          "path": "/service_accounts/gas_fee/gas_fee/unclaimed/balance",
+                          "result": {
+                            "code": 0,
+                            "bandwidth_gas_amount": 1
+                          }
+                        },
+                        "1": {
+                          "path": "/accounts/0x00ADEc28B6a845a085e03591bE7550dd68673C1C/balance",
+                          "result": {
+                            "code": 0,
+                            "bandwidth_gas_amount": 1
+                          }
+                        },
+                        "2": {
+                          "path": "/transfer/gas_fee|gas_fee|unclaimed/0x00ADEc28B6a845a085e03591bE7550dd68673C1C/1629377509815/result",
+                          "result": {
+                            "code": 0,
+                            "bandwidth_gas_amount": 1
+                          }
+                        }
+                      },
+                      "code": 0,
+                      "bandwidth_gas_amount": 0
+                    }
+                  },
+                  "code": 0,
+                  "bandwidth_gas_amount": 1
+                }
+              },
+              "1": {
+                "path": "/consensus/rewards/0x00ADEc28B6a845a085e03591bE7550dd68673C1C/unclaimed",
+                "result": {
+                  "code": 0,
+                  "bandwidth_gas_amount": 1
+                }
+              }
+            },
+            "code": 0,
+            "bandwidth_gas_amount": 0
+          }
+        },
+        "code": 0,
+        "bandwidth_gas_amount": 1,
+        "gas_amount_charged": 2420
+      });
+    });
+  });
+
+  describe('Penalties', () => {
+    function sendInvalidBlockProposal() {
+      const lastBlock = getLastBlock(server1);
+      const proposalBlock = Block.create(lastBlock.hash, [], {}, [], lastBlock.number + 1,
+          lastBlock.epoch + 1, '', server2Addr, {}, 0, 0);
+      proposalBlock.hash += '0'; // Invalid block hash
+      const proposalTxBody = {
+        operation: {
+          type: 'SET_VALUE',
+          ref: PathUtil.getConsensusProposePath(proposalBlock.number),
+          value: {
+            number: proposalBlock.number,
+            epoch: proposalBlock.epoch,
+            validators: proposalBlock.validators,
+            total_at_stake: 0,
+            proposer: server2Addr,
+            block_hash: proposalBlock.hash,
+            last_hash: proposalBlock.last_hash,
+            timestamp: proposalBlock.timestamp,
+            gas_cost_total: 0
+          }
+        },
+        nonce: -1,
+        timestamp: Date.now(),
+        gas_price: 1,
+      };
+      const proposalTx = parseOrLog(syncRequest('POST', server2 + `/sign_transaction`,
+          {json: proposalTxBody}).body.toString('utf-8')).result;
+      const invalidProposal = {
+        value: { proposalBlock, proposalTx },
+        type: ConsensusMessageTypes.PROPOSE,
+        consensusProtoVer: CONSENSUS_PROTOCOL_VERSION
+      };
+      syncRequest('POST', server1 + '/broadcast_consensus_msg', {json: invalidProposal});
+      return { proposalBlock, proposalTx };
+    }
+
+    async function waitUntilAgainstVotesInBlock(proposalBlock) {
+      let againstVotes = parseOrLog(syncRequest('GET',
+          server2 + `/get_value?ref=/consensus/number/${proposalBlock.number}/${proposalBlock.hash}/vote`)
+          .body.toString('utf-8')).result;
+      while (againstVotes === null) {
+        await CommonUtil.sleep(200);
+        againstVotes = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/consensus/number/${proposalBlock.number}/${proposalBlock.hash}/vote`)
+            .body.toString('utf-8')).result;
+      }
+      // Wait for 1 more block.
+      await waitForNewBlocks(server2, 1);
+      return againstVotes;
+    }
+
+    it('can record an offense and its evidence', async () => {
+      const { proposalBlock, proposalTx } = sendInvalidBlockProposal();
+      const againstVotesFromState = await waitUntilAgainstVotesInBlock(proposalBlock);
+      const offenseRecords = parseOrLog(syncRequest(
+          'GET', server2 + `/get_value?ref=/consensus/offense_records`).body.toString('utf-8')).result;
+      assert.deepEqual(offenseRecords, { [server2Addr]: 1 });
+      const blockWithEvidence = (parseOrLog(syncRequest('GET', server2 + `/blocks`)
+          .body.toString('utf-8')).result || [])
+              .find((block) => !CommonUtil.isEmpty(block.evidence));
+      const evidence = blockWithEvidence.evidence[server2Addr][0];
+      assert.deepEqual(blockWithEvidence.evidence[server2Addr].length, 1);
+      assert.deepEqual(evidence.offense_type, ValidatorOffenseTypes.INVALID_PROPOSAL);
+      assert.deepEqual(evidence.block, proposalBlock);
+      assert.deepEqual(evidence.transactions, [proposalTx]);
+      evidence.votes.forEach((vote) => {
+        assert.deepEqual(ConsensusUtil.isAgainstVoteTx(vote), true);
+      });
+      for (const [addr, vote] of Object.entries(againstVotesFromState)) {
+        expect(blockWithEvidence.validators[addr]).to.not.equal(undefined);
+        assert.deepEqual(vote.stake, blockWithEvidence.validators[addr].stake);
+        assert.deepEqual(vote.block_hash, proposalBlock.hash);
+        assert.deepEqual(vote.is_against, true);
+        assert.deepEqual(vote.offense_type, ValidatorOffenseTypes.INVALID_PROPOSAL);
+      }
+      const offenses = parseOrLog(syncRequest(
+        'GET', server2 + `/get_value?ref=/consensus/number/${blockWithEvidence.number}/propose/offenses`)
+        .body.toString('utf-8')).result;
+      assert.deepEqual(offenses, { [server2Addr]: { [ValidatorOffenseTypes.INVALID_PROPOSAL]: 1 } });
+    });
+
+    it('can penalize malicious validators ', async () => {
+      const offenseRecordsBefore = parseOrLog(syncRequest(
+          'GET', server2 + `/get_value?ref=/consensus/offense_records/${server2Addr}`).body.toString('utf-8')).result;
+      const stakeExpirationBefore = parseOrLog(syncRequest(
+          'GET', server2 + `/get_value?ref=/staking/consensus/${server2Addr}/0/expire_at`).body.toString('utf-8')).result;
+      const { proposalBlock } = sendInvalidBlockProposal();
+      await waitUntilAgainstVotesInBlock(proposalBlock);
+      const offenseRecordsAfter = parseOrLog(syncRequest(
+        'GET', server2 + `/get_value?ref=/consensus/offense_records/${server2Addr}`).body.toString('utf-8')).result;
+      const stakeExpirationAfter = parseOrLog(syncRequest(
+          'GET', server2 + `/get_value?ref=/staking/consensus/${server2Addr}/0/expire_at`).body.toString('utf-8')).result;
+      assert.deepEqual(offenseRecordsAfter, offenseRecordsBefore + 1);
+      assert.deepEqual(
+        stakeExpirationAfter,
+        stakeExpirationBefore + Functions.getLockupExtensionForNewOffenses(1, offenseRecordsAfter)
+      );
     });
-  })
+  });
 });
\ No newline at end of file
diff --git a/integration/he_protocol.test.js b/integration/he_protocol.test.js
new file mode 100644
index 000000000..b27733bf1
--- /dev/null
+++ b/integration/he_protocol.test.js
@@ -0,0 +1,617 @@
+const chai = require('chai');
+const assert = chai.assert;
+const expect = chai.expect;
+const _ = require("lodash");
+const spawn = require("child_process").spawn;
+const syncRequest = require('sync-request');
+const rimraf = require("rimraf")
+const PROJECT_ROOT = require('path').dirname(__filename) + "/../"
+const TRACKER_SERVER = PROJECT_ROOT + "tracker-server/index.js"
+const APP_SERVER = PROJECT_ROOT + "client/index.js"
+const {
+  CHAINS_DIR,
+} = require('../common/constants');
+const CommonUtil = require('../common/common-util');
+const {
+  waitUntilTxFinalized,
+  waitUntilNetworkIsReady,
+  parseOrLog,
+  setUpApp,
+  eraseStateGas,
+} = require('../unittest/test-util');
+
+const ENV_VARIABLES = [
+  {
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 0, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    MAX_BLOCK_NUMBERS_FOR_RECEIPTS: 100,
+    ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
+    ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
+  },
+  {
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 1, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    MAX_BLOCK_NUMBERS_FOR_RECEIPTS: 100,
+    ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
+    ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
+  },
+  {
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 2, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    MAX_BLOCK_NUMBERS_FOR_RECEIPTS: 100,
+    ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
+    ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
+  },
+  {
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 3, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    MAX_BLOCK_NUMBERS_FOR_RECEIPTS: 100,
+    ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
+    ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
+  },
+];
+
+const server1 = 'http://localhost:' + String(8081 + Number(ENV_VARIABLES[0].ACCOUNT_INDEX))
+const server2 = 'http://localhost:' + String(8081 + Number(ENV_VARIABLES[1].ACCOUNT_INDEX))
+const server3 = 'http://localhost:' + String(8081 + Number(ENV_VARIABLES[2].ACCOUNT_INDEX))
+const server4 = 'http://localhost:' + String(8081 + Number(ENV_VARIABLES[3].ACCOUNT_INDEX))
+const serverList = [ server1, server2, server3, server4 ];
+
+function startServer(application, serverName, envVars, stdioInherit = false) {
+  const options = {
+    cwd: process.cwd(),
+    env: {
+      PATH: process.env.PATH,
+      ...envVars
+    },
+  };
+  if (stdioInherit) {
+    options.stdio = 'inherit';
+  }
+  return spawn('node', [application], options).on('error', (err) => {
+    console.error(`Failed to start ${serverName} with error: ${err.message}`);
+  });
+}
+
+describe('HE Protocol', () => {
+  let tracker_proc, server1_proc, server2_proc, server3_proc, server4_proc
+
+  before(async () => {
+    rimraf.sync(CHAINS_DIR)
+
+    tracker_proc = startServer(TRACKER_SERVER, 'tracker server', { CONSOLE_LOG: false }, true);
+    await CommonUtil.sleep(3000);
+    server1_proc = startServer(APP_SERVER, 'server1', ENV_VARIABLES[0], true);
+    await CommonUtil.sleep(10000);
+    server2_proc = startServer(APP_SERVER, 'server2', ENV_VARIABLES[1], true);
+    await CommonUtil.sleep(3000);
+    server3_proc = startServer(APP_SERVER, 'server3', ENV_VARIABLES[2], true);
+    await CommonUtil.sleep(3000);
+    server4_proc = startServer(APP_SERVER, 'server4', ENV_VARIABLES[3], true);
+    await waitUntilNetworkIsReady(serverList);
+
+    const server1Addr = parseOrLog(syncRequest(
+        'GET', server1 + '/get_address').body.toString('utf-8')).result;
+    const server2Addr = parseOrLog(syncRequest(
+        'GET', server2 + '/get_address').body.toString('utf-8')).result;
+    const server3Addr = parseOrLog(syncRequest(
+        'GET', server3 + '/get_address').body.toString('utf-8')).result;
+    const server4Addr = parseOrLog(syncRequest(
+        'GET', server4 + '/get_address').body.toString('utf-8')).result;
+    await setUpApp('test', serverList, {
+      admin: {
+        [server1Addr]: true,
+        [server2Addr]: true,
+        [server3Addr]: true,
+        [server4Addr]: true,
+      }
+    });
+  });
+
+  after(() => {
+    tracker_proc.kill()
+    server1_proc.kill()
+    server2_proc.kill()
+    server3_proc.kill()
+    server4_proc.kill()
+
+    rimraf.sync(CHAINS_DIR)
+  });
+
+  describe('Health care app', () => {
+    let serviceAdmin; // = server1
+    let serviceUser; // = server2
+
+    const appName = 'he_health_care';
+    const appScenario1Label = 'app_scenario1';
+    const appScenario1TaskPath = `/apps/${appName}/${appScenario1Label}/tasks/$task_id`;
+
+    before(async () => {
+      serviceAdmin =
+          parseOrLog(syncRequest('GET', server1 + '/get_address').body.toString('utf-8')).result;
+      serviceUser =
+          parseOrLog(syncRequest('GET', server2 + '/get_address').body.toString('utf-8')).result;
+
+      // Stake
+      const appStakingPath =
+          `/staking/${appName}/${serviceAdmin}/0/stake/${Date.now()}/value`;
+      const appStakingRes = parseOrLog(syncRequest('POST', server1 + '/set_value', {json: {
+        ref: appStakingPath,
+        value: 1
+      }}).body.toString('utf-8')).result;
+      if (!(await waitUntilTxFinalized(serverList, appStakingRes.tx_hash))) {
+        console.error(`Failed to check finalization of tx.`);
+      }
+
+      // Create app
+      const manageAppPath = `/manage_app/${appName}/create/1`;
+      const createAppRes = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: {
+        ref: manageAppPath,
+        value: {
+          admin: { [serviceAdmin]: true },
+        },
+        nonce: -1,
+        timestamp: 1234567890000,
+      }}).body.toString('utf-8')).result;
+      if (!(await waitUntilTxFinalized(serverList, _.get(createAppRes, 'tx_hash')))) {
+        console.error(`Failed to check finalization of tx.`);
+      }
+    })
+
+    describe('Create app', () => {
+      it("app creation was successful", async () => {
+        const appCreationResult = parseOrLog(syncRequest(
+          'GET', server2 + `/get_value?ref=/manage_app/${appName}/create/1/result`).body.toString('utf-8')).result;
+        expect(appCreationResult.code).to.equal(0);
+      });
+    });
+
+    describe('Set owner', () => {
+      it("owner was configured properly", async () => {
+        const ownerConfig = parseOrLog(syncRequest(
+          'GET', server2 + `/get_owner?ref=/apps/${appName}`).body.toString('utf-8')).result;
+        assert.deepEqual(ownerConfig, {
+          ".owner": {
+            "owners": {
+              "0x00ADEc28B6a845a085e03591bE7550dd68673C1C": {
+                "branch_owner": true,
+                "write_function": true,
+                "write_owner": true,
+                "write_rule": true,
+              }
+            }
+          }
+        })
+      });
+    });
+
+    describe('Set rule', () => {
+      after(async () => {
+        // Clear rule
+        const request = {
+          ref: `${appScenario1TaskPath}`,
+          value: null,
+          gas_price: 1,
+        };
+        const res = parseOrLog(syncRequest('POST', server1 + '/set_rule', {json: request})
+            .body.toString('utf-8')).result;
+        assert.deepEqual(eraseStateGas(res.result, [appName]), {
+          "bandwidth_gas_amount": 1,
+          "code": 0,
+          "gas_amount_charged": "erased",
+          "gas_amount_total": {
+            "bandwidth": {
+              "app": {
+                "he_health_care": 1
+              },
+              "service": 0
+            },
+            "state": {
+              "app": {
+                "he_health_care": "erased"
+              },
+              "service": "erased"
+            }
+          },
+          "gas_cost_total": 0
+        });
+
+        // Confirm that the rule clear tx is finalized
+        const txHash = _.get(res, 'tx_hash');
+        expect(txHash).to.not.equal(null);
+        if (!(await waitUntilTxFinalized(serverList, txHash))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+      });
+
+      it("initial rule was configured properly", async () => {
+        const ruleConfig = parseOrLog(syncRequest('GET', server2 + `/get_rule?ref=/apps/${appName}`)
+            .body.toString('utf-8')).result;
+        assert.deepEqual(ruleConfig, {
+          ".rule": {
+            "write": "auth.addr === '0x00ADEc28B6a845a085e03591bE7550dd68673C1C'"
+          }
+        })
+      });
+
+      it("owner can set rule", async () => {
+        // Check the initial rule.
+        const ruleBefore = parseOrLog(syncRequest('GET',
+            server2 + `/get_rule?ref=${appScenario1TaskPath}`).body.toString('utf-8')).result;
+        assert.deepEqual(ruleBefore, null);
+
+        // Set rule
+        const request = {
+          ref: `${appScenario1TaskPath}`,
+          value: {
+            ".rule": {
+              "write": "some rule config"
+            }
+          },
+          gas_price: 1,
+        };
+        const res = parseOrLog(syncRequest('POST', server1 + '/set_rule', {json: request})
+            .body.toString('utf-8')).result;
+        assert.deepEqual(eraseStateGas(res.result, [appName]), {
+          "bandwidth_gas_amount": 1,
+          "code": 0,
+          "gas_amount_charged": "erased",
+          "gas_amount_total": {
+            "bandwidth": {
+              "app": {
+                "he_health_care": 1
+              },
+              "service": 0
+            },
+            "state": {
+              "app": {
+                "he_health_care": "erased"
+              },
+              "service": "erased"
+            }
+          },
+          "gas_cost_total": 0
+        });
+
+        // Confirm that the rule set tx is finalized
+        const txHash = _.get(res, 'tx_hash');
+        expect(txHash).to.not.equal(null);
+        if (!(await waitUntilTxFinalized(serverList, txHash))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+        const ruleAfter = parseOrLog(syncRequest(
+            'GET', server2 + `/get_rule?ref=${appScenario1TaskPath}`)
+            .body.toString('utf-8')).result;
+        assert.deepEqual(ruleAfter, {
+          ".rule": {
+            "write": "some rule config"
+          }
+        });
+      });
+    });
+
+    describe('Set function', () => {
+      after(async () => {
+        // Clear function
+        const request = {
+          ref: `${appScenario1TaskPath}`,
+          value: null
+        };
+        const res = parseOrLog(syncRequest('POST', server1 + '/set_function', {json: request})
+            .body.toString('utf-8')).result;
+        assert.deepEqual(eraseStateGas(res.result, [appName]), {
+          "bandwidth_gas_amount": 1,
+          "code": 0,
+          "gas_amount_charged": "erased",
+          "gas_amount_total": {
+            "bandwidth": {
+              "app": {
+                "he_health_care": 1
+              },
+              "service": 0
+            },
+            "state": {
+              "app": {
+                "he_health_care": "erased"
+              },
+              "service": "erased"
+            }
+          },
+          "gas_cost_total": 0
+        });
+
+        // Confirm that the function clear tx is finalized
+        const txHash = _.get(res, 'tx_hash');
+        expect(txHash).to.not.equal(null);
+        if (!(await waitUntilTxFinalized(serverList, txHash))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+      });
+
+      it("owner can set function", async () => {
+        // Check the initial function.
+        const functionBefore = parseOrLog(syncRequest('GET',
+            server2 + `/get_function?ref=${appScenario1TaskPath}`)
+            .body.toString('utf-8')).result;
+        assert.deepEqual(functionBefore, null);
+
+        // Set function
+        const request = {
+          ref: `${appScenario1TaskPath}`,
+          value: {
+            ".function": {
+              "fid": {
+                "event_listener": "https://events.ainetwork.ai/trigger",
+                "function_id": "fid",
+                "function_type": "REST",
+                "service_name": "https://ainetwork.ai"
+              }
+            }
+          }
+        };
+        const res = parseOrLog(syncRequest('POST', server1 + '/set_function', {json: request})
+            .body.toString('utf-8')).result;
+        assert.deepEqual(eraseStateGas(res.result, [appName]), {
+          "bandwidth_gas_amount": 1,
+          "code": 0,
+          "gas_amount_charged": "erased",
+          "gas_amount_total": {
+            "bandwidth": {
+              "app": {
+                "he_health_care": 1
+              },
+              "service": 0
+            },
+            "state": {
+              "app": {
+                "he_health_care": "erased"
+              },
+              "service": "erased"
+            }
+          },
+          "gas_cost_total": 0
+        });
+
+        // Confirm that the function set tx is finalized
+        const txHash = _.get(res, 'tx_hash');
+        expect(txHash).to.not.equal(null);
+        if (!(await waitUntilTxFinalized(serverList, txHash))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+        const functionAfter = parseOrLog(syncRequest(
+            'GET', server2 + `/get_function?ref=${appScenario1TaskPath}`)
+            .body.toString('utf-8')).result;
+        assert.deepEqual(functionAfter, {
+          ".function": {
+            "fid": {
+              "event_listener": "https://events.ainetwork.ai/trigger",
+              "function_id": "fid",
+              "function_type": "REST",
+              "service_name": "https://ainetwork.ai"
+            }
+          }
+        });
+      });
+    });
+
+    describe('Set value', () => {
+      before(async () => {
+        // Set rule
+        const ruleRequest = {
+          ref: `${appScenario1TaskPath}`,
+          value: {
+            ".rule": {
+              "write": true
+            }
+          },
+          gas_price: 1,
+        };
+        const ruleResp = parseOrLog(syncRequest('POST', server1 + '/set_rule', {json: ruleRequest})
+            .body.toString('utf-8')).result;
+        assert.deepEqual(eraseStateGas(ruleResp.result, [appName]), {
+          "bandwidth_gas_amount": 1,
+          "code": 0,
+          "gas_amount_charged": "erased",
+          "gas_amount_total": {
+            "bandwidth": {
+              "app": {
+                "he_health_care": 1
+              },
+              "service": 0
+            },
+            "state": {
+              "app": {
+                "he_health_care": "erased"
+              },
+              "service": "erased"
+            }
+          },
+          "gas_cost_total": 0
+        });
+
+        // Confirm that the rule set tx is finalized
+        const ruleTxHash = _.get(ruleResp, 'tx_hash');
+        expect(ruleTxHash).to.not.equal(null);
+        if (!(await waitUntilTxFinalized(serverList, ruleTxHash))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+
+        // Set function
+        const functionRequest = {
+          ref: `${appScenario1TaskPath}`,
+          value: {
+            ".function": {
+              "call_he_worker": {
+                "event_listener": "https://events.ainetwork.ai/trigger",
+                "function_id": "call_he_worker",
+                "function_type": "REST",
+                "service_name": "https://ainetwork.ai"
+              }
+            }
+          }
+        };
+        const functionResp = parseOrLog(syncRequest('POST',
+            server1 + '/set_function', {json: functionRequest})
+            .body.toString('utf-8')).result;
+        assert.deepEqual(eraseStateGas(functionResp.result, [appName]), {
+          "bandwidth_gas_amount": 1,
+          "code": 0,
+          "gas_amount_charged": "erased",
+          "gas_amount_total": {
+            "bandwidth": {
+              "app": {
+                "he_health_care": 1
+              },
+              "service": 0
+            },
+            "state": {
+              "app": {
+                "he_health_care": "erased"
+              },
+              "service": "erased"
+            }
+          },
+          "gas_cost_total": 0
+        });
+
+        // Confirm that the function set tx is finalized
+        const functionTxHash = _.get(functionResp, 'tx_hash');
+        expect(functionTxHash).to.not.equal(null);
+        if (!(await waitUntilTxFinalized(serverList, functionTxHash))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+      });
+
+      after(async () => {
+        // Clear rule
+        const ruleRequest = {
+          ref: `${appScenario1TaskPath}`,
+          value: null,
+          gas_price: 1,
+        };
+        const ruleResp = parseOrLog(syncRequest('POST', server1 + '/set_rule', {json: ruleRequest})
+            .body.toString('utf-8')).result;
+        assert.deepEqual(eraseStateGas(ruleResp.result, [appName]), {
+          "bandwidth_gas_amount": 1,
+          "code": 0,
+          "gas_amount_charged": "erased",
+          "gas_amount_total": {
+            "bandwidth": {
+              "app": {
+                "he_health_care": 1
+              },
+              "service": 0
+            },
+            "state": {
+              "app": {
+                "he_health_care": "erased"
+              },
+              "service": "erased"
+            }
+          },
+          "gas_cost_total": 0
+        });
+
+        // Confirm that the rule clear tx is finalized
+        const ruleTxHash = _.get(ruleResp, 'tx_hash');
+        expect(ruleTxHash).to.not.equal(null);
+        if (!(await waitUntilTxFinalized(serverList, ruleTxHash))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+
+        // Clear function
+        const functioinRequest = {
+          ref: `${appScenario1TaskPath}`,
+          value: null
+        };
+        const functionResp = parseOrLog(syncRequest('POST',
+            server1 + '/set_function', {json: functioinRequest})
+            .body.toString('utf-8')).result;
+        assert.deepEqual(eraseStateGas(functionResp.result, [appName]), {
+          "bandwidth_gas_amount": 1,
+          "code": 0,
+          "gas_amount_charged": "erased",
+          "gas_amount_total": {
+            "bandwidth": {
+              "app": {
+                "he_health_care": 1
+              },
+              "service": 0
+            },
+            "state": {
+              "app": {
+                "he_health_care": "erased"
+              },
+              "service": "erased"
+            }
+          },
+          "gas_cost_total": 0
+        });
+
+        // Confirm that the function clear tx is finalized
+        const functionTxHash = _.get(functionResp, 'tx_hash');
+        expect(functionTxHash).to.not.equal(null);
+        if (!(await waitUntilTxFinalized(serverList, functionTxHash))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+      });
+
+      it("user can set value to trigger function", async () => {
+        const task0Path = `/apps/${appName}/${appScenario1Label}/tasks/0`;
+
+        // Check the initial value.
+        const valueBefore = parseOrLog(syncRequest('GET', server1 + `/get_value?ref=${task0Path}`)
+            .body.toString('utf-8')).result;
+        assert.deepEqual(valueBefore, null);
+
+        // Set value
+        const request = {
+          ref: `${task0Path}`,
+          value: {
+            data: 'task0 data'
+          }
+        };
+        const res = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: request})
+            .body.toString('utf-8')).result;
+        assert.deepEqual(eraseStateGas(res.result, [appName]), {
+          "bandwidth_gas_amount": 1,
+          "code": 0,
+          "func_results": {
+            "call_he_worker": {  // Function triggering was done
+              "bandwidth_gas_amount": 10,
+              "code": 0
+            }
+          },
+          "gas_amount_charged": "erased",
+          "gas_amount_total": {
+            "bandwidth": {
+              "app": {
+                "he_health_care": 11
+              },
+              "service": 0
+            },
+            "state": {
+              "app": {
+                "he_health_care": "erased"
+              },
+              "service": "erased"
+            }
+          },
+          "gas_cost_total": 0
+        });
+
+        // Confirm that the value set tx is finalized
+        const txHash = _.get(res, 'tx_hash');
+        expect(txHash).to.not.equal(null);
+        if (!(await waitUntilTxFinalized(serverList, txHash))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+        const valueAfter = parseOrLog(syncRequest('GET', server1 + `/get_value?ref=${task0Path}`)
+            .body.toString('utf-8')).result;
+        assert.deepEqual(valueAfter, {
+          "data": "task0 data"
+        });
+      });
+    });
+  });
+});
diff --git a/integration/he_sharding.test.js b/integration/he_sharding.test.js
new file mode 100644
index 000000000..e31846930
--- /dev/null
+++ b/integration/he_sharding.test.js
@@ -0,0 +1,391 @@
+const path = require('path');
+const chai = require('chai');
+const assert = chai.assert;
+const expect = chai.expect;
+const spawn = require("child_process").spawn;
+const ainUtil = require('@ainblockchain/ain-util');
+const syncRequest = require('sync-request');
+const rimraf = require("rimraf")
+const _ = require('lodash');
+const { parseOrLog } = require('../unittest/test-util');
+const PROJECT_ROOT = require('path').dirname(__filename) + "/../"
+const TRACKER_SERVER = PROJECT_ROOT + "tracker-server/index.js"
+const APP_SERVER = PROJECT_ROOT + "client/index.js"
+const {
+  CHAINS_DIR,
+} = require('../common/constants');
+const {
+  ConsensusStates
+} = require('../consensus/constants');
+const CommonUtil = require('../common/common-util');
+const {
+  readConfigFile,
+  waitForNewBlocks,
+  waitUntilNodeSyncs,
+  waitUntilTxFinalized,
+  waitUntilNetworkIsReady,
+  setUpApp,
+} = require('../unittest/test-util');
+
+const ENV_VARIABLES = [
+  {
+    // For parent chain poc node
+    MIN_NUM_VALIDATORS: 1, ACCOUNT_INDEX: 0, DEBUG: true,
+    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+  },
+  {
+    // For shard chain tracker
+    PORT: 9090, P2P_PORT: 6000,
+    CONSOLE_LOG: false
+  },
+  {
+    GENESIS_CONFIGS_DIR: 'genesis-configs/he-shard',
+    PORT: 9091, P2P_PORT: 6001,
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 0,
+    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
+    ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
+  },
+  {
+    GENESIS_CONFIGS_DIR: 'genesis-configs/he-shard',
+    PORT: 9092, P2P_PORT: 6002,
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 1,
+    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
+    ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
+  },
+  {
+    GENESIS_CONFIGS_DIR: 'genesis-configs/he-shard',
+    PORT: 9093, P2P_PORT: 6003,
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 2,
+    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
+    ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
+  },
+  {
+    GENESIS_CONFIGS_DIR: 'genesis-configs/he-shard',
+    PORT: 9094, P2P_PORT: 6004,
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 3,
+    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
+    ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
+  },
+];
+
+const parentServer = 'http://localhost:8081';
+const parentServerList = [ parentServer ];
+const server1 = 'http://localhost:' + String(9091 + Number(ENV_VARIABLES[2].ACCOUNT_INDEX))
+const server2 = 'http://localhost:' + String(9091 + Number(ENV_VARIABLES[3].ACCOUNT_INDEX))
+const server3 = 'http://localhost:' + String(9091 + Number(ENV_VARIABLES[4].ACCOUNT_INDEX))
+const server4 = 'http://localhost:' + String(9091 + Number(ENV_VARIABLES[5].ACCOUNT_INDEX))
+const shardServerList = [ server1, server2, server3, server4 ];
+
+function startServer(application, serverName, envVars, stdioInherit = false) {
+  const options = {
+    cwd: process.cwd(),
+    env: {
+      PATH: process.env.PATH,
+      ...envVars
+    },
+  };
+  if (stdioInherit) {
+    options.stdio = 'inherit';
+  }
+  return spawn('node', [application], options).on('error', (err) => {
+    console.error(`Failed to start ${serverName} with error: ${err.message}`);
+  });
+}
+
+// Needed to make sure the shard initialization is finished
+// before other shard nodes start
+async function waitUntilShardReporterStarts() {
+  let consensusStatus;
+  while (true) {
+    consensusStatus = parseOrLog(syncRequest('GET', server1 + '/get_consensus_status')
+        .body.toString('utf-8')).result;
+    if (consensusStatus && consensusStatus.state === ConsensusStates.RUNNING) return;
+    await CommonUtil.sleep(1000);
+  }
+}
+
+describe('HE Sharding', async () => {
+  const appName = 'he_health_care';
+  const token =
+      readConfigFile(path.resolve(__dirname, '../genesis-configs/he-shard', 'genesis_token.json'));
+  const parentAccounts =
+      readConfigFile(path.resolve(__dirname, '../genesis-configs/base', 'genesis_accounts.json'));
+  const parentServerAddr = parentAccounts.others[0].address;
+  const accounts =
+      readConfigFile(path.resolve(__dirname, '../genesis-configs/he-shard', 'genesis_accounts.json'));
+  const shardOwnerAddr = accounts.owner.address;
+  const shardReporterAddr = accounts.others[0].address;
+  const sharding =
+      readConfigFile(path.resolve(__dirname, '../genesis-configs/he-shard', 'genesis_sharding.json'));
+
+  let parent_tracker_proc, parent_server_proc,
+      tracker_proc, server1_proc, server2_proc, server3_proc, server4_proc;
+
+  before(async () => {
+    rimraf.sync(CHAINS_DIR)
+
+    parent_tracker_proc =
+        startServer(TRACKER_SERVER, 'parent tracker server', { CONSOLE_LOG: false }, true);
+    await CommonUtil.sleep(2000);
+    parent_server_proc = startServer(APP_SERVER, 'parent server', ENV_VARIABLES[0], true);
+    await CommonUtil.sleep(15000);
+    // Give AIN to sharding owner and reporter
+    const shardReportRes = parseOrLog(syncRequest(
+      'POST', parentServer + '/set', { json: {
+        op_list: [
+          {
+            type: 'SET_VALUE',
+            ref: `/transfer/${parentServerAddr}/${shardOwnerAddr}/${Date.now()}/value`,
+            value: 100
+          },
+          {
+            type: 'SET_VALUE',
+            ref: `/transfer/${parentServerAddr}/${shardReporterAddr}/${Date.now()}/value`,
+            value: 100
+          }
+        ],
+        nonce: -1
+      } }).body.toString('utf-8')
+    ).result;
+    await waitUntilTxFinalized(parentServerList, shardReportRes.tx_hash);
+    // Create app at the parent chain for the shard
+    await setUpApp(appName, parentServerList, { admin: { [shardOwnerAddr]: true } });
+    
+    tracker_proc = startServer(TRACKER_SERVER, 'tracker server', ENV_VARIABLES[1], true);
+    await CommonUtil.sleep(3000);
+    server1_proc = startServer(APP_SERVER, 'server1', ENV_VARIABLES[2], true);
+    await CommonUtil.sleep(10000);
+    await waitUntilShardReporterStarts();
+    server2_proc = startServer(APP_SERVER, 'server2', ENV_VARIABLES[3], true);
+    await CommonUtil.sleep(3000);
+    server3_proc = startServer(APP_SERVER, 'server3', ENV_VARIABLES[4], true);
+    await CommonUtil.sleep(3000);
+    server4_proc = startServer(APP_SERVER, 'server4', ENV_VARIABLES[5], true);
+    await CommonUtil.sleep(3000); // Before shard reporting begins
+  });
+
+  after(() => {
+    parent_tracker_proc.kill()
+    parent_server_proc.kill()
+    tracker_proc.kill()
+    server1_proc.kill()
+    server2_proc.kill()
+    server3_proc.kill()
+    server4_proc.kill()
+
+    rimraf.sync(CHAINS_DIR)
+  });
+
+  describe('Parent chain initialization', () => {
+    describe('DB values', () => {
+      it('sharding', () => {
+        const body = parseOrLog(syncRequest(
+            'GET', parentServer +
+            `/get_value?ref=/sharding/shard/${ainUtil.encode(sharding.sharding_path)}`)
+          .body.toString('utf-8'));
+        assert.deepEqual(body, {
+          code: 0,
+          result: Object.assign(
+            {},
+            sharding,
+            {
+              shard_owner: shardOwnerAddr,
+              shard_reporter: shardReporterAddr
+            }
+          )
+        });
+      });
+
+      it('.shard', () => {
+        const body = parseOrLog(syncRequest(
+            'GET', parentServer + `/get_value?ref=${sharding.sharding_path}/.shard`)
+          .body.toString('utf-8'));
+        assert.deepEqual(body, {
+          code: 0,
+          result: {
+            sharding_enabled: true,
+            proof_hash_map: {
+              latest: -1
+            }
+          },
+        });
+      });
+    });
+
+    describe('DB functions', () => {
+      it('sharding path', () => {
+        const body = parseOrLog(syncRequest(
+            'GET', parentServer +
+            `/get_function?ref=${sharding.sharding_path}/.shard/proof_hash_map`)
+          .body.toString('utf-8'));
+        expect(body.code).to.equal(0);
+        expect(body.result).to.not.be.null;
+        assert.deepEqual(body.result, {
+          "$block_number": {
+            "proof_hash": {
+              ".function": {
+                "_updateLatestShardReport": {
+                  "function_type": "NATIVE",
+                  "function_id": "_updateLatestShardReport"
+                }
+              }
+            }
+          }
+        })
+      });
+    });
+
+    describe('DB rules', () => {
+      it('sharding path', () => {
+        const body = parseOrLog(syncRequest(
+            'GET', parentServer +
+            `/get_rule?ref=${sharding.sharding_path}/` +
+            `.shard/proof_hash_map/$block_number/proof_hash`)
+          .body.toString('utf-8'));
+        expect(body.code).to.equal(0);
+        expect(body.result['.rule']['write']).to.have.string(shardReporterAddr);
+      });
+    });
+
+    describe('DB owners', () => {
+      it('sharding path', () => {
+        const body = parseOrLog(syncRequest(
+            'GET', parentServer + `/get_owner?ref=${sharding.sharding_path}`)
+          .body.toString('utf-8'));
+        expect(body.code).to.equal(0);
+        expect(body.result['.owner'].owners[shardOwnerAddr]).to.not.be.null;
+      });
+    });
+  });
+
+  describe('Shard chain initialization', () => {
+    before(async () => {
+      await waitUntilNetworkIsReady(shardServerList);
+      await setUpApp(appName, shardServerList, { admin: { [shardOwnerAddr]: true } });
+    });
+    
+    describe('DB values', () => {
+      it('token', () => {
+        const body = parseOrLog(syncRequest('GET', server1 + '/get_value?ref=/token')
+          .body.toString('utf-8'));
+        assert.deepEqual(body, {code: 0, result: token});
+      })
+
+      it('accounts', () => {
+        const body1 = parseOrLog(syncRequest(
+            'GET', server1 + '/get_value?ref=/accounts/' + shardOwnerAddr + '/balance')
+          .body.toString('utf-8'));
+        expect(body1.code).to.equal(0);
+        expect(body1.result).to.be.above(0);
+
+        const body2 = parseOrLog(syncRequest(
+            'GET', server1 + '/get_value?ref=/accounts/' + shardReporterAddr + '/balance')
+          .body.toString('utf-8'));
+        expect(body2.code).to.equal(0);
+        expect(body2.result).to.be.above(0);
+      })
+
+      it('sharding', () => {
+        const body = parseOrLog(syncRequest('GET', server1 + '/get_value?ref=/sharding/config')
+          .body.toString('utf-8'));
+        expect(body.code).to.equal(0);
+        expect(body.result.sharding_protocol).to.equal(sharding.sharding_protocol);
+        expect(body.result.sharding_path).to.equal(sharding.sharding_path);
+      })
+    })
+
+    describe('DB functions', () => {
+      it('sharding', () => {
+        const body = parseOrLog(syncRequest('GET', server2 + '/get_function?ref=/transfer')
+          .body.toString('utf-8'));
+        expect(body.code).to.equal(0);
+        expect(body.result).to.not.be.null;
+      })
+    })
+
+    describe('DB rules', () => {
+      it('sharding', () => {
+        const body = parseOrLog(syncRequest('GET', server3 + '/get_rule?ref=/sharding/config')
+          .body.toString('utf-8'));
+        expect(body.code).to.equal(0);
+        expect(body.result['.rule']['write']).to.have.string(shardOwnerAddr);
+      })
+    })
+
+    describe('DB owners', () => {
+      it('sharding', () => {
+        const body = parseOrLog(syncRequest('GET', server4 + '/get_owner?ref=/sharding/config')
+            .body.toString('utf-8'));
+        expect(body.code).to.equal(0);
+        expect(body.result['.owner'].owners[shardOwnerAddr]).to.not.be.null;
+      })
+    })
+  });
+
+  describe('State proof hash reporting', () => {
+    before(async () => {
+      await waitForNewBlocks(server1, sharding.reporting_period * 3);
+    });
+
+    describe('Periodic reports', () => {
+      it ('reports proof hashes periodically', () => {
+        const body = parseOrLog(syncRequest(
+            'GET', parentServer + `/get_value?ref=${sharding.sharding_path}/.shard/proof_hash_map`)
+          .body.toString('utf-8'));
+        expect(body.code).to.equal(0);
+        let blockNumber = 0;
+        const sortedReports = _.without(
+            Object.keys(body.result), 'latest').sort((a, b) => Number(a) - Number(b));
+        for (const key of sortedReports) {
+          expect(blockNumber).to.equal(Number(key));
+          blockNumber++;
+        }
+      });
+    });
+
+    describe('Latest block number', () => {
+      it ('updates latest block number', () => {
+        const body = parseOrLog(syncRequest(
+            'GET', parentServer + `/get_value?ref=${sharding.sharding_path}/.shard/proof_hash_map`)
+          .body.toString('utf-8'));
+        expect(body.code).to.equal(0);
+        const latest = body.result.latest;
+        const sortedReports = _.without(
+            Object.keys(body.result), 'latest').sort((a, b) => Number(a) - Number(b));
+        const highest = sortedReports[sortedReports.length - 1];
+        expect(latest).to.equal(Number(highest));
+      });
+    });
+
+    describe('Shard reporter node restart', () => {
+      it('can resume reporting after missing some reports', async () => {
+        const reportsBefore = parseOrLog(syncRequest(
+            'GET', parentServer + `/get_value?ref=${sharding.sharding_path}/.shard/proof_hash_map`)
+          .body.toString('utf-8'));
+        console.log(`        --> Shutting down server[0]...`);
+        server1_proc.kill();
+        await waitForNewBlocks(server2, sharding.reporting_period);
+        console.log(`        --> Restarting server[0]...`);
+        server1_proc = startServer(APP_SERVER, 'server1', ENV_VARIABLES[2]);
+        await waitForNewBlocks(server2, sharding.reporting_period * 2);
+        await waitUntilNodeSyncs(server1);
+        await waitForNewBlocks(server1, sharding.reporting_period);
+        const reportsAfter = parseOrLog(syncRequest(
+            'GET', parentServer + `/get_value?ref=${sharding.sharding_path}/.shard/proof_hash_map`)
+          .body.toString('utf-8'));
+        let blockNumber = 0;
+        const sortedReports = _.without(
+            Object.keys(reportsAfter.result), 'latest').sort((a, b) => Number(a) - Number(b));
+        for (const key of sortedReports) {
+          expect(blockNumber).to.equal(Number(key));
+          blockNumber++;
+        }
+        expect(reportsAfter.result.latest).to.be.greaterThan(reportsBefore.result.latest);
+      });
+    });
+  });
+})
diff --git a/integration/node.test.js b/integration/node.test.js
index 1c1895624..d3f7aeb26 100644
--- a/integration/node.test.js
+++ b/integration/node.test.js
@@ -13,50 +13,52 @@ const APP_SERVER = PROJECT_ROOT + "client/index.js"
 const {
   CURRENT_PROTOCOL_VERSION,
   CHAINS_DIR,
-  HASH_DELIMITER,
   FunctionResultCode,
   GenesisAccounts,
-  ProofProperties,
   TX_BYTES_LIMIT,
   BATCH_TX_LIST_SIZE_LIMIT,
   TX_POOL_SIZE_LIMIT_PER_ACCOUNT,
   MICRO_AIN,
 } = require('../common/constants');
 const CommonUtil = require('../common/common-util');
+const PathUtil = require('../common/path-util');
 const {
   waitUntilTxFinalized,
   parseOrLog,
   setUpApp,
   getLastBlockNumber,
+  waitUntilNetworkIsReady,
   waitForNewBlocks,
   getBlockByNumber,
+  eraseStateGas,
 } = require('../unittest/test-util');
+const DB = require('../db');
 
 const ENV_VARIABLES = [
   {
-    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 0, EPOCH_MS: 1000, DEBUG: false,
-    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 0, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
     MAX_BLOCK_NUMBERS_FOR_RECEIPTS: 100,
     ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
     ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
   },
   {
-    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 1, EPOCH_MS: 1000, DEBUG: false,
-    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 1, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
     MAX_BLOCK_NUMBERS_FOR_RECEIPTS: 100,
     ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
     ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
   },
   {
-    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 2, EPOCH_MS: 1000, DEBUG: false,
-    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 2, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
     MAX_BLOCK_NUMBERS_FOR_RECEIPTS: 100,
     ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
     ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
   },
   {
-    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 3, EPOCH_MS: 1000, DEBUG: false,
-    CONSOLE_LOG: false, ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
+    MIN_NUM_VALIDATORS: 4, ACCOUNT_INDEX: 3, DEBUG: false, CONSOLE_LOG: false,
+    ENABLE_DEV_SET_CLIENT_API: true, ENABLE_GAS_FEE_WORKAROUND: true,
     MAX_BLOCK_NUMBERS_FOR_RECEIPTS: 100,
     ADDITIONAL_OWNERS: 'test:unittest/data/owners_for_testing.json',
     ADDITIONAL_RULES: 'test:unittest/data/rules_for_testing.json'
@@ -160,22 +162,27 @@ async function cleanUp() {
       op_list: [
         {
           type: 'SET_VALUE',
-          ref: '/apps/test/test_value/some/path',
+          ref: '/apps/test/test_value',
+          value: null
+        },
+        {
+          type: 'SET_VALUE',
+          ref: '/apps/test/test_state_info',
           value: null
         },
         {
           type: 'SET_RULE',
-          ref: '/apps/test/test_rule/some/path',
+          ref: '/apps/test/test_rule',
           value: null
         },
         {
           type: 'SET_FUNCTION',
-          ref: '/apps/test/test_function/some/path',
+          ref: '/apps/test/test_function',
           value: null
         },
         {
           type: 'SET_OWNER',
-          ref: '/apps/test/test_owner/some/path',
+          ref: '/apps/test/test_owner',
           value: null
         },
       ],
@@ -195,16 +202,15 @@ describe('Blockchain Node', () => {
     rimraf.sync(CHAINS_DIR)
 
     tracker_proc = startServer(TRACKER_SERVER, 'tracker server', { CONSOLE_LOG: false }, true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(3000);
     server1_proc = startServer(APP_SERVER, 'server1', ENV_VARIABLES[0], true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(10000);
     server2_proc = startServer(APP_SERVER, 'server2', ENV_VARIABLES[1], true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(3000);
     server3_proc = startServer(APP_SERVER, 'server3', ENV_VARIABLES[2], true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(3000);
     server4_proc = startServer(APP_SERVER, 'server4', ENV_VARIABLES[3], true);
-    await CommonUtil.sleep(2000);
-
+    await waitUntilNetworkIsReady(serverList);
 
     const server1Addr = parseOrLog(syncRequest(
         'GET', server1 + '/get_address').body.toString('utf-8')).result;
@@ -502,25 +508,13 @@ describe('Blockchain Node', () => {
       it('get_state_proof', () => {
         const body = parseOrLog(syncRequest('GET', server1 + '/get_state_proof?ref=/')
             .body.toString('utf-8'));
-        const ownersBody = parseOrLog(syncRequest('GET', server1 + `/get_state_proof?ref=/owners`)
-            .body.toString('utf-8'));
-        const rulesBody = parseOrLog(syncRequest('GET', server1 + `/get_state_proof?ref=/rules`)
-            .body.toString('utf-8'));
-        const valuesBody = parseOrLog(syncRequest('GET', server1 + `/get_state_proof?ref=/values`)
-            .body.toString('utf-8'));
-        const functionsBody = parseOrLog(syncRequest(
-            'GET', server1 + `/get_state_proof?ref=/functions`)
-            .body.toString('utf-8'));
-        const ownersProof = ownersBody.result.owners[ProofProperties.PROOF_HASH];
-        const rulesProof = rulesBody.result.rules[ProofProperties.PROOF_HASH];
-        const valuesProof = valuesBody.result.values[ProofProperties.PROOF_HASH];
-        const functionProof = functionsBody.result.functions[ProofProperties.PROOF_HASH];
-        const preimage = `owners${HASH_DELIMITER}${ownersProof}${HASH_DELIMITER}` +
-            `rules${HASH_DELIMITER}${rulesProof}${HASH_DELIMITER}` +
-            `values${HASH_DELIMITER}${valuesProof}${HASH_DELIMITER}` +
-            `functions${HASH_DELIMITER}${functionProof}`;
-        const proofHash = CommonUtil.hashString(CommonUtil.toString(preimage));
-        assert.deepEqual(body, { code: 0, result: { '.proof_hash': proofHash } });
+        body.result['.proof_hash'] = 'erased';
+        assert.deepEqual(body, {
+          "code": 0,
+          "result": {
+            ".proof_hash": "erased"
+          }
+        });
       });
     });
 
@@ -531,12 +525,13 @@ describe('Blockchain Node', () => {
                 .body.toString('utf-8'));
         // Erase some properties for stable comparison.
         infoBody.result.tree_bytes = 0;
+        infoBody.result.proof_hash = 'erased';
         infoBody.result.version = 'erased';
         assert.deepEqual(
             infoBody, {
               code: 0,
               result: {
-                "proof_hash": "0x972cc2f16c7b20173eb9426d2698459a9351d38b5bca7d2af70124cd617bbeac",
+                "proof_hash": "erased",
                 "tree_bytes": 0,
                 "tree_height": 2,
                 "tree_size": 5,
@@ -551,9 +546,9 @@ describe('Blockchain Node', () => {
             'GET', server1 + `/get_state_usage?app_name=test`)
                 .body.toString('utf-8'));
         assert.deepEqual(body.result, {
-          "tree_height": 17,
-          "tree_size": 52,
-          "tree_bytes": 10076,
+          "tree_height": 23,
+          "tree_size": 62,
+          "tree_bytes": 11966,
         });
       });
     });
@@ -693,30 +688,14 @@ describe('Blockchain Node', () => {
 
     describe('ain_getStateProof', () => {
       it('returns correct value', () => {
-        const ownersBody = parseOrLog(syncRequest('GET', server1 + `/get_state_proof?ref=/owners`)
-            .body.toString('utf-8'));
-        const rulesBody = parseOrLog(syncRequest('GET', server1 + `/get_state_proof?ref=/rules`)
-            .body.toString('utf-8'));
-        const valuesBody = parseOrLog(syncRequest('GET', server1 + `/get_state_proof?ref=/values`)
-            .body.toString('utf-8'));
-        const functionsBody = parseOrLog(syncRequest(
-            'GET', server1 + `/get_state_proof?ref=/functions`)
-            .body.toString('utf-8'));
-        const ownersProof = ownersBody.result.owners[ProofProperties.PROOF_HASH];
-        const rulesProof = rulesBody.result.rules[ProofProperties.PROOF_HASH];
-        const valuesProof = valuesBody.result.values[ProofProperties.PROOF_HASH];
-        const functionProof = functionsBody.result.functions[ProofProperties.PROOF_HASH];
-        const preimage = `owners${HASH_DELIMITER}${ownersProof}${HASH_DELIMITER}` +
-            `rules${HASH_DELIMITER}${rulesProof}${HASH_DELIMITER}` +
-            `values${HASH_DELIMITER}${valuesProof}${HASH_DELIMITER}` +
-            `functions${HASH_DELIMITER}${functionProof}`;
-        const proofHash = CommonUtil.hashString(CommonUtil.toString(preimage));
-
         const ref = '/';
         const request = { ref, protoVer: CURRENT_PROTOCOL_VERSION };
         return jayson.client.http(server1 + '/json-rpc').request('ain_getStateProof', request)
         .then(res => {
-          assert.deepEqual(res.result.result, { '.proof_hash': proofHash });
+          res.result.result['.proof_hash'] = 'erased';
+          assert.deepEqual(res.result.result, {
+            ".proof_hash": "erased"
+          });
         })
       })
     })
@@ -730,9 +709,10 @@ describe('Blockchain Node', () => {
           const stateInfo = res.result.result;
           // Erase some properties for stable comparison.
           stateInfo.tree_bytes = 0;
+          stateInfo.proof_hash = 'erased';
           stateInfo.version = 'erased';
           assert.deepEqual(stateInfo, {
-            "proof_hash": "0x972cc2f16c7b20173eb9426d2698459a9351d38b5bca7d2af70124cd617bbeac",
+            "proof_hash": "erased",
             "tree_height": 2,
             "tree_size": 5,
             "tree_bytes": 0,
@@ -749,9 +729,9 @@ describe('Blockchain Node', () => {
         .then(res => {
           const stateUsage = res.result.result;
           assert.deepEqual(stateUsage, {
-            "tree_height": 17,
-            "tree_size": 52,
-            "tree_bytes": 10076,
+            "tree_height": 23,
+            "tree_size": 62,
+            "tree_bytes": 11966,
           });
         })
       })
@@ -956,7 +936,7 @@ describe('Blockchain Node', () => {
       it('inc_value', async () => {
         // Check the original value.
         const resultBefore = parseOrLog(syncRequest(
-            'GET', server1 + '/get_value?ref=/apps/some/wrong/path2')
+            'GET', server1 + '/get_value?ref=/apps/test/test_value/some/path2')
             .body.toString('utf-8')).result;
         assert.deepEqual(resultBefore, null);
 
@@ -1493,7 +1473,7 @@ describe('Blockchain Node', () => {
               "bandwidth_gas_amount": 1
             },
           },
-          "gas_amount_charged": 1552,
+          "gas_amount_charged": 0,
           "gas_amount_total": {
             "bandwidth": {
               "app": {
@@ -1503,9 +1483,9 @@ describe('Blockchain Node', () => {
             },
             "state": {
               "app": {
-                "test": 3070
+                "test": 4622
               },
-              "service": 1552
+              "service": 0
             }
           },
           "gas_cost_total": 0
@@ -1801,6 +1781,9 @@ describe('Blockchain Node', () => {
         expect(CommonUtil.isArray(body.result)).to.equal(true);
         for (let i = 0; i < body.result.length; i++) {
           const result = body.result[i];
+          if (!(await waitUntilTxFinalized(serverList, result.tx_hash))) {
+            console.error(`Failed to check finalization of tx.`);
+          }
           result.tx_hash = 'erased';
         }
         assert.deepEqual(body.result, [
@@ -1878,7 +1861,7 @@ describe('Blockchain Node', () => {
             "result": {
               "code": 0,
               "bandwidth_gas_amount": 1,
-              "gas_amount_charged": 1552,
+              "gas_amount_charged": 0,
               "gas_amount_total": {
                 "bandwidth": {
                   "service": 0,
@@ -1887,7 +1870,10 @@ describe('Blockchain Node', () => {
                   }
                 },
                 "state": {
-                  "service": 1552
+                  "app": {
+                    "test": 1552
+                  },
+                  "service": 0
                 }
               },
               "gas_cost_total": 0
@@ -1968,7 +1954,7 @@ describe('Blockchain Node', () => {
                   "bandwidth_gas_amount": 1
                 }
               },
-              "gas_amount_charged": 1552,
+              "gas_amount_charged": 0,
               "gas_amount_total": {
                 "bandwidth": {
                   "service": 0,
@@ -1978,9 +1964,9 @@ describe('Blockchain Node', () => {
                 },
                 "state": {
                   "app": {
-                    "test": 3070
+                    "test": 4622
                   },
-                  "service": 1552
+                  "service": 0
                 }
               },
               "gas_cost_total": 0
@@ -1990,7 +1976,6 @@ describe('Blockchain Node', () => {
         expect(body.code).to.equal(0);
 
         // Confirm that the value is set properly.
-        await CommonUtil.sleep(6);
         const resultAfter = parseOrLog(syncRequest(
             'GET', server1 + '/get_value?ref=/apps/test/test_value/some200/path')
             .body.toString('utf-8')).result;
@@ -2025,7 +2010,7 @@ describe('Blockchain Node', () => {
                 value: "some other202 value",
               },
               timestamp: Date.now(),
-              nonce: nonce
+              nonce: -1
             },
             {
               operation: {
@@ -2034,7 +2019,7 @@ describe('Blockchain Node', () => {
                 value: 10
               },
               timestamp: Date.now(),
-              nonce: nonce + 1
+              nonce: -1
             },
             {
               operation: {
@@ -2043,7 +2028,7 @@ describe('Blockchain Node', () => {
                 value: 10
               },
               timestamp: Date.now(),
-              nonce: nonce + 2
+              nonce: -1
             },
             {
               operation: {
@@ -2052,7 +2037,7 @@ describe('Blockchain Node', () => {
                 value: "some other202 value",
               },
               timestamp: Date.now(),
-              nonce: nonce + 3
+              nonce: -1
             },
             {
               operation: {
@@ -2070,7 +2055,7 @@ describe('Blockchain Node', () => {
                 }
               },
               timestamp: Date.now(),
-              nonce: nonce + 3
+              nonce: -1
             },
             {
               operation: {
@@ -2083,7 +2068,7 @@ describe('Blockchain Node', () => {
                 }
               },
               timestamp: Date.now(),
-              nonce: nonce + 4
+              nonce: -1
             },
             {
               operation: {
@@ -2103,7 +2088,7 @@ describe('Blockchain Node', () => {
                 }
               },
               timestamp: Date.now(),
-              nonce: nonce + 5
+              nonce: -1
             },
             {
               operation: {
@@ -2166,7 +2151,7 @@ describe('Blockchain Node', () => {
                 ]
               },
               timestamp: Date.now(),
-              nonce: nonce + 6
+              nonce: -1
             }
           ]
         };
@@ -2176,6 +2161,9 @@ describe('Blockchain Node', () => {
         expect(CommonUtil.isArray(body.result)).to.equal(true);
         for (let i = 0; i < body.result.length; i++) {
           const result = body.result[i];
+          if (!(await waitUntilTxFinalized(serverList, result.tx_hash))) {
+            console.error(`Failed to check finalization of tx.`);
+          }
           result.tx_hash = 'erased';
         }
         assert.deepEqual(body.result, [
@@ -2274,7 +2262,7 @@ describe('Blockchain Node', () => {
             "result": {
               "code": 0,
               "bandwidth_gas_amount": 1,
-              "gas_amount_charged": 1552,
+              "gas_amount_charged": 0,
               "gas_amount_total": {
                 "bandwidth": {
                   "service": 0,
@@ -2283,7 +2271,10 @@ describe('Blockchain Node', () => {
                   }
                 },
                 "state": {
-                  "service": 1552
+                  "app": {
+                    "test": 1552
+                  },
+                  "service": 0
                 }
               },
               "gas_cost_total": 0
@@ -2364,7 +2355,7 @@ describe('Blockchain Node', () => {
                   "bandwidth_gas_amount": 1
                 }
               },
-              "gas_amount_charged": 1552,
+              "gas_amount_charged": 0,
               "gas_amount_total": {
                 "bandwidth": {
                   "service": 0,
@@ -2374,9 +2365,9 @@ describe('Blockchain Node', () => {
                 },
                 "state": {
                   "app": {
-                    "test": 3070
+                    "test": 4622
                   },
-                  "service": 1552
+                  "service": 0
                 }
               },
               "gas_cost_total": 0
@@ -2386,7 +2377,6 @@ describe('Blockchain Node', () => {
         expect(body.code).to.equal(0);
 
         // Confirm that the value is set properly.
-        await CommonUtil.sleep(6);
         const resultAfter = parseOrLog(syncRequest(
             'GET', server1 + '/get_value?ref=/apps/test/test_value/some202/path')
             .body.toString('utf-8')).result;
@@ -3209,6 +3199,7 @@ describe('Blockchain Node', () => {
       const res = parseOrLog(syncRequest('POST', server2 + '/set', {
         json: {
           op_list: [
+            // allowed_path_with_fid
             {
               type: 'SET_FUNCTION',
               ref: '/apps/test/test_function_triggering/allowed_path_with_fid/value',
@@ -3239,6 +3230,7 @@ describe('Blockchain Node', () => {
                 }
               }
             },
+            // not_allowed_path_with_fid
             {
               type: 'SET_FUNCTION',
               ref: '/apps/test/test_function_triggering/not_allowed_path_with_fid/value',
@@ -3269,6 +3261,7 @@ describe('Blockchain Node', () => {
                 }
               }
             },
+            // allowed_path_with_fids
             {
               type: 'SET_FUNCTION',
               ref: '/apps/test/test_function_triggering/allowed_path_with_fids/value',
@@ -3299,6 +3292,7 @@ describe('Blockchain Node', () => {
                 }
               }
             },
+            // not_allowed_path_with_fids
             {
               type: 'SET_FUNCTION',
               ref: '/apps/test/test_function_triggering/not_allowed_path_with_fids/value',
@@ -3329,6 +3323,7 @@ describe('Blockchain Node', () => {
                 }
               }
             },
+            // set_owner_allowed_path_with_fid
             {
               type: 'SET_FUNCTION',
               ref: '/apps/test/test_function_triggering/set_owner_allowed_path_with_fid/value',
@@ -3363,6 +3358,7 @@ describe('Blockchain Node', () => {
                 }
               }
             },
+            // set_owner_not_allowed_path_with_fid
             {
               type: 'SET_FUNCTION',
               ref: '/apps/test/test_function_triggering/set_owner_not_allowed_path_with_fid/value',
@@ -3397,6 +3393,7 @@ describe('Blockchain Node', () => {
                 }
               }
             },
+            // rest_function_path
             {
               type: 'SET_FUNCTION',
               ref: '/apps/test/test_function_triggering/rest_function_path',
@@ -3435,75 +3432,25 @@ describe('Blockchain Node', () => {
         json: {
           op_list: [
             {
-              type: 'SET_FUNCTION',
-              ref: '/apps/test/test_function_triggering/allowed_path_with_fid/value',
-              value: null
-            },
-            {
-              type: 'SET_RULE',
-              ref: '/apps/test/test_function_triggering/allowed_path_with_fid/value',
-              value: null
-            },
-            {
-              type: 'SET_FUNCTION',
-              ref: '/apps/test/test_function_triggering/not_allowed_path_with_fid/value',
-              value: null
-            },
-            {
-              type: 'SET_RULE',
-              ref: '/apps/test/test_function_triggering/not_allowed_path_with_fid/value',
-              value: null
-            },
-            {
-              type: 'SET_FUNCTION',
-              ref: '/apps/test/test_function_triggering/allowed_path_with_fids/value',
-              value: null
-            },
-            {
-              type: 'SET_RULE',
-              ref: '/apps/test/test_function_triggering/allowed_path_with_fids/value',
-              value: null
-            },
-            {
-              type: 'SET_FUNCTION',
-              ref: '/apps/test/test_function_triggering/not_allowed_path_with_fids/value',
+              type: 'SET_VALUE',
+              ref: '/apps/test/test_function_triggering',
               value: null
             },
             {
               type: 'SET_RULE',
-              ref: '/apps/test/test_function_triggering/not_allowed_path_with_fids/value',
-              value: null
-            },
-            {
-              type: 'SET_FUNCTION',
-              ref: '/apps/test/test_function_triggering/set_owner_allowed_path_with_fid/value',
-              value: null
-            },
-            {
-              type: 'SET_OWNER',
-              ref: '/apps/test/test_function_triggering/set_owner_allowed_path_with_fid',
+              ref: '/apps/test/test_function_triggering',
               value: null
             },
             {
               type: 'SET_FUNCTION',
-              ref: '/apps/test/test_function_triggering/set_owner_not_allowed_path_with_fid/value',
+              ref: '/apps/test/test_function_triggering',
               value: null
             },
             {
               type: 'SET_OWNER',
-              ref: '/apps/test/test_function_triggering/set_owner_not_allowed_path_with_fid',
+              ref: '/apps/test/test_function_triggering',
               value: null
             },
-            {
-              type: 'SET_FUNCTION',
-              ref: '/apps/test/test_function_triggering/rest_function_path',
-              value: null,
-            },
-            {
-              type: 'SET_RULE',
-              ref: '/apps/test/test_function_triggering/rest_function_path',
-              value: null,
-            },
           ],
           nonce: -1,
         }
@@ -3612,7 +3559,7 @@ describe('Blockchain Node', () => {
             "code": 0,
             "func_results": {
               "_saveLastTx": {
-                "code": "FAILURE",
+                "code": 1,
                 "bandwidth_gas_amount": 0,
                 "op_results": {
                   "0": {
@@ -3666,7 +3613,7 @@ describe('Blockchain Node', () => {
             "code": 0,
             "func_results": {
               "_saveLastTx": {
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 0,
                 "op_results": {
                   "0": {
@@ -3680,7 +3627,7 @@ describe('Blockchain Node', () => {
               }
             },
             "bandwidth_gas_amount": 1,
-            "gas_amount_charged": 0,
+            "gas_amount_charged": 8,
             "gas_amount_total": {
               "bandwidth": {
                 "app": {
@@ -3690,9 +3637,9 @@ describe('Blockchain Node', () => {
               },
               "state": {
                 "app": {
-                  "test": 1252
+                  "test": 1412
                 },
-                "service": 0
+                "service": 8
               }
             },
             "gas_cost_total": 0,
@@ -3718,7 +3665,7 @@ describe('Blockchain Node', () => {
             "code": 0,
             "func_results": {
               "_saveLastTx": {
-                "code": "FAILURE",
+                "code": 1,
                 "bandwidth_gas_amount": 0,
                 "op_results": {
                   "0": {
@@ -3769,7 +3716,7 @@ describe('Blockchain Node', () => {
             "code": 0,
             "func_results": {
               "_saveLastTx": {
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 0,
                 "op_results": {
                   "0": {
@@ -3783,7 +3730,7 @@ describe('Blockchain Node', () => {
               }
             },
             "bandwidth_gas_amount": 1,
-            "gas_amount_charged": 0,
+            "gas_amount_charged": 8,
             "gas_amount_total": {
               "bandwidth": {
                 "app": {
@@ -3793,9 +3740,9 @@ describe('Blockchain Node', () => {
               },
               "state": {
                 "app": {
-                  "test": 1046
+                  "test": 1414
                 },
-                "service": 0
+                "service": 8
               }
             },
             "gas_cost_total": 0,
@@ -3824,7 +3771,7 @@ describe('Blockchain Node', () => {
             "code": 0,
             "func_results": {
               "_setOwnerConfig": {
-                "code": "FAILURE",
+                "code": 1,
                 "bandwidth_gas_amount": 0,
                 "op_results": {
                   "0": {
@@ -3875,7 +3822,7 @@ describe('Blockchain Node', () => {
             "code": 0,
             "func_results": {
               "_setOwnerConfig": {
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 0,
                 "op_results": {
                   "0": {
@@ -3889,7 +3836,7 @@ describe('Blockchain Node', () => {
               }
             },
             "bandwidth_gas_amount": 1,
-            "gas_amount_charged": 0,
+            "gas_amount_charged": 8,
             "gas_amount_total": {
               "bandwidth": {
                 "app": {
@@ -3899,9 +3846,9 @@ describe('Blockchain Node', () => {
               },
               "state": {
                 "app": {
-                  "test": 2832
+                  "test": 3200
                 },
-                "service": 0
+                "service": 8
               }
             },
             "gas_cost_total": 0,
@@ -3920,6 +3867,18 @@ describe('Blockchain Node', () => {
     });
 
     describe('Function execution', () => {
+      before(async () => {
+        const appStakingPath =
+            `/staking/test/${serviceAdmin}/0/stake/${Date.now()}/value`;
+        const appStakingRes = parseOrLog(syncRequest('POST', server1 + '/set_value', {json: {
+          ref: appStakingPath,
+          value: 1
+        }}).body.toString('utf-8')).result;
+        if (!(await waitUntilTxFinalized(serverList, appStakingRes.tx_hash))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+      });
+
       describe('/set_value', () => {
         it("when successful with function triggering", async () => {
           const valuePath = '/apps/test/test_function_triggering/allowed_path1/value';
@@ -4281,61 +4240,61 @@ describe('Blockchain Node', () => {
           nonce: -1,
           timestamp: 1234567890000,
         }}).body.toString('utf-8')).result;
-        assert.deepEqual(createAppRes, {
-          "result": {
-            "code": 0,
-            "func_results": {
-              "_createApp": {
-                "code": "SUCCESS",
-                "bandwidth_gas_amount": 0,
-                "op_results": {
-                  "0": {
-                    "path": "/apps/test_service_create_app0",
-                    "result": {
-                      "code": 0,
-                      "bandwidth_gas_amount": 1
-                    }
-                  },
-                  "1": {
-                    "path": "/apps/test_service_create_app0",
-                    "result": {
-                      "code": 0,
-                      "bandwidth_gas_amount": 1
-                    }
-                  },
-                  "2": {
-                    "path": "/manage_app/test_service_create_app0/config",
-                    "result": {
-                      "code": 0,
-                      "bandwidth_gas_amount": 1
-                    }
-                  },
-                  "3": {
-                    "path": "/manage_app/test_service_create_app0/create/1/result",
-                    "result": {
-                      "code": 0,
-                      "bandwidth_gas_amount": 1
-                    }
+        assert.deepEqual(eraseStateGas(createAppRes.result, ['test_service_create_app0']), {
+          "func_results": {
+            "_createApp": {
+              "code": 0,
+              "bandwidth_gas_amount": 0,
+              "op_results": {
+                "0": {
+                  "path": "/apps/test_service_create_app0",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                },
+                "1": {
+                  "path": "/apps/test_service_create_app0",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                },
+                "2": {
+                  "path": "/manage_app/test_service_create_app0/config",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                },
+                "3": {
+                  "path": "/manage_app/test_service_create_app0/create/1/result",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
                   }
                 }
               }
-            },
-            "bandwidth_gas_amount": 1,
-            "gas_amount_charged": 2399,
-            "gas_amount_total": {
-              "bandwidth": {
-                "app": {
-                  "test_service_create_app0": 2
-                },
-                "service": 3
+            }
+          },
+          "code": 0,
+          "bandwidth_gas_amount": 1,
+          "gas_amount_charged": 'erased',
+          "gas_amount_total": {
+            "bandwidth": {
+              "app": {
+                "test_service_create_app0": 2
               },
-              "state": {
-                "service": 2396
-              }
+              "service": 3
             },
-            "gas_cost_total": 0
+            "state": {
+              "app": {
+                "test_service_create_app0": 'erased'
+              },
+              "service": 'erased'
+            }
           },
-          "tx_hash": "0x4e2a4bc009347bbaa1a14f1ddecb0f2b06d02d46326d33def7c346c613093079"
+          "gas_cost_total": 0
         });
         if (!(await waitUntilTxFinalized(serverList, _.get(createAppRes, 'tx_hash')))) {
           console.error(`Failed to check finalization of tx.`);
@@ -4357,7 +4316,7 @@ describe('Blockchain Node', () => {
             "code": 0,
             "func_results": {
               "_createApp": {
-                "code": "INVALID_SERVICE_NAME",
+                "code": 300,
                 "bandwidth_gas_amount": 0,
                 "op_results": {
                   "0": {
@@ -4409,63 +4368,63 @@ describe('Blockchain Node', () => {
           nonce: -1,
           timestamp: 1234567890000,
         }}).body.toString('utf-8')).result;
-        assert.deepEqual(createAppRes, {
-          "result": {
-            "code": 0,
-            "func_results": {
-              "_createApp": {
-                "code": "SUCCESS",
-                "bandwidth_gas_amount": 0,
-                "op_results": {
-                  "0": {
-                    "path": "/apps/test_service_create_app1",
-                    "result": {
-                      "code": 0,
-                      "bandwidth_gas_amount": 1
-                    }
-                  },
-                  "1": {
-                    "path": "/apps/test_service_create_app1",
-                    "result": {
-                      "code": 0,
-                      "bandwidth_gas_amount": 1
-                    }
-                  },
-                  "2": {
-                    "path": "/manage_app/test_service_create_app1/config",
-                    "result": {
-                      "code": 0,
-                      "bandwidth_gas_amount": 1
-                    }
-                  },
-                  "3": {
-                    "path": "/manage_app/test_service_create_app1/create/0/result",
-                    "result": {
-                      "code": 0,
-                      "bandwidth_gas_amount": 1
-                    }
+        assert.deepEqual(eraseStateGas(createAppRes.result, ['test_service_create_app1']), {
+          "func_results": {
+            "_createApp": {
+              "code": 0,
+              "bandwidth_gas_amount": 0,
+              "op_results": {
+                "0": {
+                  "path": "/apps/test_service_create_app1",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
                   }
-                }
-              }
-            },
-            "bandwidth_gas_amount": 1,
-            "gas_amount_charged": 2763,
-            "gas_amount_total": {
-              "bandwidth": {
-                "app": {
-                  "test_service_create_app1": 2
                 },
-                "service": 3
-              },
-              "state": {
-                "service": 2760
-              }
-            },
-            "gas_cost_total": 0
-          },
-          "tx_hash": "0xaa4625dcf4dfa36d6e9a23b64236b88379cac1338d76b915e843fd7cfeda14bb"
-        });
-        if (!(await waitUntilTxFinalized(serverList, createAppRes.tx_hash))) {
+                "1": {
+                  "path": "/apps/test_service_create_app1",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                },
+                "2": {
+                  "path": "/manage_app/test_service_create_app1/config",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                },
+                "3": {
+                  "path": "/manage_app/test_service_create_app1/create/0/result",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                }
+              }
+            }
+          },
+          "code": 0,
+          "bandwidth_gas_amount": 1,
+          "gas_amount_charged": 'erased',
+          "gas_amount_total": {
+            "bandwidth": {
+              "app": {
+                "test_service_create_app1": 2
+              },
+              "service": 3
+            },
+            "state": {
+              "app": {
+                "test_service_create_app1": 'erased'
+              },
+              "service": 'erased'
+            }
+          },
+          "gas_cost_total": 0
+        });
+        if (!(await waitUntilTxFinalized(serverList, createAppRes.tx_hash))) {
           console.error(`Failed to check finalization of tx.`);
         }
         const appConfig = parseOrLog(syncRequest('GET', 
@@ -4519,7 +4478,7 @@ describe('Blockchain Node', () => {
           timestamp: 1234567890000,
           nonce: -1,
         }}).body.toString('utf-8'));
-        assert.deepEqual(_.get(body, 'result.result'), {
+        assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
           "func_results": {
             "_transfer": {
               "op_results": {
@@ -4545,19 +4504,19 @@ describe('Blockchain Node', () => {
                   }
                 }
               },
-              "code": "SUCCESS",
+              "code": 0,
               "bandwidth_gas_amount": 1000
             }
           },
           "code": 0,
           "bandwidth_gas_amount": 1,
-          "gas_amount_charged": 2860,
+          "gas_amount_charged": 'erased',
           "gas_amount_total": {
             "bandwidth": {
               "service": 1004
             },
             "state": {
-              "service": 1856
+              "service": 'erased'
             }
           },
           "gas_cost_total": 0,
@@ -4575,7 +4534,7 @@ describe('Blockchain Node', () => {
           timestamp: 1234567890000,
           nonce: -1,
         }}).body.toString('utf-8'));
-        assert.deepEqual(_.get(body, 'result.result'), {
+        assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
           "func_results": {
             "_transfer": {
               "op_results": {
@@ -4601,19 +4560,19 @@ describe('Blockchain Node', () => {
                   }
                 }
               },
-              "code": "SUCCESS",
+              "code": 0,
               "bandwidth_gas_amount": 0
             }
           },
           "code": 0,
           "bandwidth_gas_amount": 1,
-          "gas_amount_charged": 1190,
+          "gas_amount_charged": 'erased',
           "gas_amount_total": {
             "bandwidth": {
               "service": 4
             },
             "state": {
-              "service": 1186
+              "service": 'erased'
             }
           },
           "gas_cost_total": 0,
@@ -4631,7 +4590,7 @@ describe('Blockchain Node', () => {
           timestamp: 1234567890000,
           nonce: -1,
         }}).body.toString('utf-8'));
-        assert.deepEqual(_.get(body, 'result.result'), {
+        assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
           "func_results": {
             "_stake": {
               "op_results": {
@@ -4663,7 +4622,7 @@ describe('Blockchain Node', () => {
                             }
                           }
                         },
-                        "code": "SUCCESS",
+                        "code": 0,
                         "bandwidth_gas_amount": 1000
                       }
                     },
@@ -4693,19 +4652,19 @@ describe('Blockchain Node', () => {
                   }
                 }
               },
-              "code": "SUCCESS",
+              "code": 0,
               "bandwidth_gas_amount": 0
             }
           },
           "code": 0,
           "bandwidth_gas_amount": 1,
-          "gas_amount_charged": 4906,
+          "gas_amount_charged": 'erased',
           "gas_amount_total": {
             "bandwidth": {
               "service": 1008
             },
             "state": {
-              "service": 3898
+              "service": 'erased'
             }
           },
           "gas_cost_total": 0,
@@ -4723,7 +4682,7 @@ describe('Blockchain Node', () => {
           timestamp: 1234567890001,
           nonce: -1,
         }}).body.toString('utf-8'));
-        assert.deepEqual(_.get(body, 'result.result'), {
+        assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
           "func_results": {
             "_stake": {
               "op_results": {
@@ -4755,7 +4714,7 @@ describe('Blockchain Node', () => {
                             }
                           }
                         },
-                        "code": "SUCCESS",
+                        "code": 0,
                         "bandwidth_gas_amount": 0
                       }
                     },
@@ -4764,20 +4723,13 @@ describe('Blockchain Node', () => {
                   }
                 },
                 "1": {
-                  "path": "/staking/test_service_gas_fee/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204/0/expire_at",
-                  "result": {
-                    "code": 0,
-                    "bandwidth_gas_amount": 1
-                  }
-                },
-                "2": {
                   "path": "/staking/test_service_gas_fee/balance_total",
                   "result": {
                     "code": 0,
                     "bandwidth_gas_amount": 1
                   }
                 },
-                "3": {
+                "2": {
                   "path": "/staking/test_service_gas_fee/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204/0/stake/101/result",
                   "result": {
                     "code": 0,
@@ -4785,19 +4737,19 @@ describe('Blockchain Node', () => {
                   }
                 }
               },
-              "code": "SUCCESS",
+              "code": 0,
               "bandwidth_gas_amount": 0
             }
           },
           "code": 0,
           "bandwidth_gas_amount": 1,
-          "gas_amount_charged": 2408,
+          "gas_amount_charged": 'erased',
           "gas_amount_total": {
             "bandwidth": {
-              "service": 8
+              "service": 7
             },
             "state": {
-              "service": 2400
+              "service": 'erased'
             }
           },
           "gas_cost_total": 0,
@@ -4816,7 +4768,7 @@ describe('Blockchain Node', () => {
         assert.deepEqual(_.get(body, 'result.result'), {
           "func_results": {
             "0x11111": {
-              "code": "SUCCESS",
+              "code": 0,
               "bandwidth_gas_amount": 10,
             }
           },
@@ -4832,7 +4784,7 @@ describe('Blockchain Node', () => {
             },
             "state": {
               "app": {
-                "test": 216
+                "test": 424
               },
               "service": 0
             }
@@ -5000,54 +4952,48 @@ describe('Blockchain Node', () => {
           nonce: -1,
           timestamp: 1234567890000,
         }}).body.toString('utf-8'));
-        assert.deepEqual(body, {
-          "code": 0,
-          "result": {
-            "result": {
+        assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
+          "func_results": {
+            "_transfer": {
               "code": 0,
-              "func_results": {
-                "_transfer": {
-                  "code": "SUCCESS",
-                  "bandwidth_gas_amount": 1000,
-                  "op_results": {
-                    "0": {
-                      "path": "/accounts/0x00ADEc28B6a845a085e03591bE7550dd68673C1C/balance",
-                      "result": {
-                        "code": 0,
-                        "bandwidth_gas_amount": 1
-                      }
-                    },
-                    "1": {
-                      "path": "/service_accounts/staking/test_service/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204|0/balance",
-                      "result": {
-                        "code": 0,
-                        "bandwidth_gas_amount": 1
-                      }
-                    },
-                    "2": {
-                      "path": "/transfer/0x00ADEc28B6a845a085e03591bE7550dd68673C1C/staking|test_service|0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204|0/1/result",
-                      "result": {
-                        "code": 0,
-                        "bandwidth_gas_amount": 1
-                      }
-                    }
+              "bandwidth_gas_amount": 1000,
+              "op_results": {
+                "0": {
+                  "path": "/accounts/0x00ADEc28B6a845a085e03591bE7550dd68673C1C/balance",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
                   }
-                }
-              },
-              "bandwidth_gas_amount": 1,
-              "gas_amount_charged": 3094,
-              "gas_amount_total": {
-                "bandwidth": {
-                  "service": 1004
                 },
-                "state": {
-                  "service": 2090
+                "1": {
+                  "path": "/service_accounts/staking/test_service/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204|0/balance",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                },
+                "2": {
+                  "path": "/transfer/0x00ADEc28B6a845a085e03591bE7550dd68673C1C/staking|test_service|0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204|0/1/result",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
                 }
-              },
-              "gas_cost_total": 0
+              }
+            }
+          },
+          "code": 0,
+          "bandwidth_gas_amount": 1,
+          "gas_amount_charged": 'erased',
+          "gas_amount_total": {
+            "bandwidth": {
+              "service": 1004
             },
-            "tx_hash": "0x62f01969d903d7a6f184279634249941a2c312e896f045c071afe78ac635fe96"
-          }
+            "state": {
+              "service": 'erased'
+            }
+          },
+          "gas_cost_total": 0
         });
         if (!(await waitUntilTxFinalized([server2], _.get(body, 'result.tx_hash')))) {
           console.error(`Failed to check finalization of tx.`);
@@ -5127,11 +5073,10 @@ describe('Blockchain Node', () => {
             nonce: -1,
             timestamp: 1234567890000,
           }}).body.toString('utf-8'));
-          assert.deepEqual(_.get(body, 'result.result'), {
-            "code": 0,
+          assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
             "func_results": {
               "_stake": {
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 0,
                 "op_results": {
                   "0": {
@@ -5140,7 +5085,7 @@ describe('Blockchain Node', () => {
                       "code": 0,
                       "func_results": {
                         "_transfer": {
-                          "code": "SUCCESS",
+                          "code": 0,
                           "bandwidth_gas_amount": 1000,
                           "op_results": {
                             "0": {
@@ -5194,14 +5139,15 @@ describe('Blockchain Node', () => {
                 }
               }
             },
+            "code": 0,
             "bandwidth_gas_amount": 1,
-            "gas_amount_charged": 4902,
+            "gas_amount_charged": 'erased',
             "gas_amount_total": {
               "bandwidth": {
                 "service": 1008
               },
               "state": {
-                "service": 3894
+                "service": 'erased'
               }
             },
             "gas_cost_total": 0,
@@ -5269,71 +5215,6 @@ describe('Blockchain Node', () => {
           expect(afterStakingAccountBalance).to.equal(beforeStakingAccountBalance);
         });
 
-        it('stake: stake with invalid timestamp', async () => {
-          const account = {
-            "address": "0x07A43138CC760C85A5B1F115aa60eADEaa0bf417",
-            "private_key": "0e9876c7e7966fb0237892eb2e890b4738d0e50adfcfe089ef31f5a1579d65cd",
-            "public_key": "1cc01c94edce1d5807685dc04de0a0e445b560090eb421fc087f95080eb7a12a41145cc17cf4476a1d2ec0c1f737f5d84e5d0fecbfb370869845714e4ecfdd53"
-          };
-          const transferPath = `/transfer/${transferFrom}/${account.address}`;
-          const body = parseOrLog(syncRequest('POST', server1 + '/set_value', {json: {
-            ref: transferPath + '/100/value',
-            value: 1000
-          }}).body.toString('utf-8'));
-          expect(body.code).to.equals(0);
-          if (!(await waitUntilTxFinalized(serverList, _.get(body, 'result.tx_hash')))) {
-            console.error(`Failed to check finalization of tx.`);
-          }
-          const txBody = {
-            operation: {
-              type: 'SET_VALUE',
-              value: stakeAmount,
-              ref: `/staking/test_service_staking/${account.address}/0/stake/1/value`
-            },
-            timestamp: Date.now() + 100000,
-            nonce: 0
-          }
-          const signature =
-              ainUtil.ecSignTransaction(txBody, Buffer.from(account.private_key, 'hex'));
-
-          const jsonRpcClient = jayson.client.http(server2 + '/json-rpc');
-          return jsonRpcClient.request('ain_sendSignedTransaction', {
-            tx_body: txBody,
-            signature,
-            protoVer: CURRENT_PROTOCOL_VERSION
-          }).then(res => {
-            assert.deepEqual(_.get(res, 'result.result.result'), {
-              "code": 0,
-              "func_results": {
-                "_stake": {
-                  "code": "FAILURE",
-                  "bandwidth_gas_amount": 0,
-                  "op_results": {
-                    "0": {
-                      "path": "/staking/test_service_staking/0x07A43138CC760C85A5B1F115aa60eADEaa0bf417/0/stake/1/result",
-                      "result": {
-                        "code": 0,
-                        "bandwidth_gas_amount": 1,
-                      }
-                    }
-                  }
-                }
-              },
-              "bandwidth_gas_amount": 1,
-              "gas_amount_charged": 2,
-              "gas_amount_total": {
-                "bandwidth": {
-                  "service": 2
-                },
-                "state": {
-                  "service": 0
-                }
-              },
-              "gas_cost_total": 0,
-            });
-          });
-        });
-
         it('stake: stake with the same record_id', async () => {
           const body = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: {
             ref: stakePath + '/1/value',
@@ -5429,11 +5310,10 @@ describe('Blockchain Node', () => {
             nonce: -1,
             timestamp: 1234567890000,
           }}).body.toString('utf-8'));
-          assert.deepEqual(_.get(body, 'result.result'), {
-            "code": 0,
+          assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
             "func_results": {
               "_unstake": {
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 0,
                 "op_results": {
                   "0": {
@@ -5442,7 +5322,7 @@ describe('Blockchain Node', () => {
                       "code": 0,
                       "func_results": {
                         "_transfer": {
-                          "code": "SUCCESS",
+                          "code": 0,
                           "bandwidth_gas_amount": 0,
                           "op_results": {
                             "0": {
@@ -5489,14 +5369,15 @@ describe('Blockchain Node', () => {
                 }
               }
             },
+            "code": 0,
             "bandwidth_gas_amount": 1,
-            "gas_amount_charged": 3127,
+            "gas_amount_charged": 'erased',
             "gas_amount_total": {
               "bandwidth": {
                 "service": 7
               },
               "state": {
-                "service": 3120
+                "service": 'erased'
               }
             },
             "gas_cost_total": 0,
@@ -5628,11 +5509,10 @@ describe('Blockchain Node', () => {
           nonce: -1,
           timestamp: 1234567890000,
         }}).body.toString('utf-8'));
-        assert.deepEqual(_.get(body, 'result.result'), {
-          "code": 0,
+        assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
           "func_results": {
             "_pay": {
-              "code": "SUCCESS",
+              "code": 0,
               "bandwidth_gas_amount": 0,
               "op_results": {
                 "0": {
@@ -5641,7 +5521,7 @@ describe('Blockchain Node', () => {
                     "code": 0,
                     "func_results": {
                       "_transfer": {
-                        "code": "SUCCESS",
+                        "code": 0,
                         "bandwidth_gas_amount": 1000,
                         "op_results": {
                           "0": {
@@ -5681,14 +5561,15 @@ describe('Blockchain Node', () => {
               }
             }
           },
+          "code": 0,
           "bandwidth_gas_amount": 1,
-          "gas_amount_charged": 5472,
+          "gas_amount_charged": 'erased',
           "gas_amount_total": {
             "bandwidth": {
               "service": 1006
             },
             "state": {
-              "service": 4466
+              "service": 'erased'
             }
           },
           "gas_cost_total": 0,
@@ -5775,11 +5656,10 @@ describe('Blockchain Node', () => {
           nonce: -1,
           timestamp: 1234567890000,
         }}).body.toString('utf-8'));
-        assert.deepEqual(_.get(body, 'result.result'), {
-          "code": 0,
+        assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
           "func_results": {
             "_claim": {
-              "code": "SUCCESS",
+              "code": 0,
               "bandwidth_gas_amount": 0,
               "op_results": {
                 "0": {
@@ -5788,7 +5668,7 @@ describe('Blockchain Node', () => {
                     "code": 0,
                     "func_results": {
                       "_transfer": {
-                        "code": "SUCCESS",
+                        "code": 0,
                         "bandwidth_gas_amount": 0,
                         "op_results": {
                           "0": {
@@ -5828,14 +5708,15 @@ describe('Blockchain Node', () => {
               }
             }
           },
+          "code": 0,
           "bandwidth_gas_amount": 1,
-          "gas_amount_charged": 3388,
+          "gas_amount_charged": 'erased',
           "gas_amount_total": {
             "bandwidth": {
               "service": 6
             },
             "state": {
-              "service": 3382
+              "service": 'erased'
             }
           },
           "gas_cost_total": 0,
@@ -5998,16 +5879,16 @@ describe('Blockchain Node', () => {
             nonce: -1,
             timestamp: 1234567890000,
           }}).body.toString('utf-8'));
-          assert.deepEqual(_.get(body, 'result.result'), {
+          assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
             "code": 0,
             "bandwidth_gas_amount": 1,
-            "gas_amount_charged": 1241,
+            "gas_amount_charged": 'erased',
             "gas_amount_total": {
               "bandwidth": {
                 "service": 1
               },
               "state": {
-                "service": 1240
+                "service": 'erased'
               }
             },
             "gas_cost_total": 0,
@@ -6067,11 +5948,10 @@ describe('Blockchain Node', () => {
             nonce: -1,
             timestamp: 1234567890000,
           }}).body.toString('utf-8'));
-          assert.deepEqual(_.get(body, 'result.result'), {
-            "code": 0,
+          assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
             "func_results": {
               "_hold": {
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 0,
                 "op_results": {
                   "0": {
@@ -6080,7 +5960,7 @@ describe('Blockchain Node', () => {
                       "code": 0,
                       "func_results": {
                         "_transfer": {
-                          "code": "SUCCESS",
+                          "code": 0,
                           "bandwidth_gas_amount": 1000,
                           "op_results": {
                             "0": {
@@ -6120,14 +6000,15 @@ describe('Blockchain Node', () => {
                 }
               }
             },
+            "code": 0,
             "bandwidth_gas_amount": 1,
-            "gas_amount_charged": 4474,
+            "gas_amount_charged": 'erased',
             "gas_amount_total": {
               "bandwidth": {
                 "service": 1006
               },
               "state": {
-                "service": 3468
+                "service": 'erased'
               }
             },
             "gas_cost_total": 0,
@@ -6206,11 +6087,10 @@ describe('Blockchain Node', () => {
             nonce: -1,
             timestamp: 1234567890000,
           }}).body.toString('utf-8'));
-          assert.deepEqual(_.get(body, 'result.result'), {
-            "code": 0,
+          assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
             "func_results": {
               "_release": {
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 0,
                 "op_results": {
                   "0": {
@@ -6219,7 +6099,7 @@ describe('Blockchain Node', () => {
                       "code": 0,
                       "func_results": {
                         "_transfer": {
-                          "code": "SUCCESS",
+                          "code": 0,
                           "bandwidth_gas_amount": 0,
                           "op_results": {
                             "0": {
@@ -6259,14 +6139,15 @@ describe('Blockchain Node', () => {
                 }
               }
             },
+            "code": 0,
             "bandwidth_gas_amount": 1,
-            "gas_amount_charged": 3206,
+            "gas_amount_charged": 'erased',
             "gas_amount_total": {
               "bandwidth": {
                 "service": 6
               },
               "state": {
-                "service": 3200
+                "service": 'erased'
               }
             },
             "gas_cost_total": 0,
@@ -6327,16 +6208,16 @@ describe('Blockchain Node', () => {
             nonce: -1,
             timestamp: 1234567890000,
           }}).body.toString('utf-8'));
-          assert.deepEqual(_.get(body, 'result.result'), {
+          assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
             "code": 0,
             "bandwidth_gas_amount": 1,
-            "gas_amount_charged": 1303,
+            "gas_amount_charged": 'erased',
             "gas_amount_total": {
               "bandwidth": {
                 "service": 1
               },
               "state": {
-                "service": 1302
+                "service": 'erased'
               }
             },
             "gas_cost_total": 0,
@@ -6386,11 +6267,10 @@ describe('Blockchain Node', () => {
             nonce: -1,
             timestamp: 1234567890000,
           }}).body.toString('utf-8'));
-          assert.deepEqual(_.get(body, 'result.result'), {
-            "code": 0,
+          assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
             "func_results": {
               "_hold": {
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 0,
                 "op_results": {
                   "0": {
@@ -6399,7 +6279,7 @@ describe('Blockchain Node', () => {
                       "code": 0,
                       "func_results": {
                         "_transfer": {
-                          "code": "SUCCESS",
+                          "code": 0,
                           "bandwidth_gas_amount": 1000,
                           "op_results": {
                             "0": {
@@ -6439,14 +6319,15 @@ describe('Blockchain Node', () => {
                 }
               }
             },
+            "code": 0,
             "bandwidth_gas_amount": 1,
-            "gas_amount_charged": 4904,
+            "gas_amount_charged": 'erased',
             "gas_amount_total": {
               "bandwidth": {
                 "service": 1006
               },
               "state": {
-                "service": 3898
+                "service": 'erased'
               }
             },
             "gas_cost_total": 0,
@@ -6483,11 +6364,10 @@ describe('Blockchain Node', () => {
             nonce: -1,
             timestamp: 1234567890000,
           }}).body.toString('utf-8'));
-          assert.deepEqual(_.get(body, 'result.result'), {
-            "code": 0,
+          assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
             "func_results": {
               "_release": {
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 0,
                 "op_results": {
                   "0": {
@@ -6496,7 +6376,7 @@ describe('Blockchain Node', () => {
                       "code": 0,
                       "func_results": {
                         "_transfer": {
-                          "code": "SUCCESS",
+                          "code": 0,
                           "bandwidth_gas_amount": 0,
                           "op_results": {
                             "0": {
@@ -6536,14 +6416,15 @@ describe('Blockchain Node', () => {
                 }
               }
             },
+            "code": 0,
             "bandwidth_gas_amount": 1,
-            "gas_amount_charged": 3330,
+            "gas_amount_charged": 'erased',
             "gas_amount_total": {
               "bandwidth": {
                 "service": 6
               },
               "state": {
-                "service": 3324
+                "service": 'erased'
               }
             },
             "gas_cost_total": 0,
@@ -6622,73 +6503,722 @@ describe('Blockchain Node', () => {
         });
       });
     });
-  });
 
-  describe('Billing', async () => {
-    let serviceAdmin; // = server1
-    let billingUserA; // = server2
-    let billingUserB; // = server3
-    let userBalancePathA;
-    let userBalancePathB;
-    const billingAccountBalancePathA = '/get_value?ref=/service_accounts/billing/test_billing/A/balance';
-    before(async () => {
-      serviceAdmin =
-          parseOrLog(syncRequest('GET', server1 + '/get_address').body.toString('utf-8')).result;
-      billingUserA =
-          parseOrLog(syncRequest('GET', server2 + '/get_address').body.toString('utf-8')).result;
-      billingUserB =
-          parseOrLog(syncRequest('GET', server3 + '/get_address').body.toString('utf-8')).result;
-      userBalancePathA = `/get_value?ref=/accounts/${billingUserA}/balance`;
-      userBalancePathB = `/get_value?ref=/accounts/${billingUserB}/balance`;
-      const adminConfig = {
-        [serviceAdmin]: true,
-        [billingUserA]: true,
-        [billingUserB]: true
-      };
-      const billingConfig = {
-        A: { 
-          users: {
-            [serviceAdmin]: true,
-            [billingUserA]: true
-          }
-        },
-        B: {
-          users: {
-            [serviceAdmin]: true,
-            [billingUserB]: true
+    describe('Checkout: _openCheckout, _closeCheckout', () => {
+      const client = jayson.client.http(server1 + '/json-rpc');
+      const tokenType = 'ETH';
+      const tokenId = '0xB16c0C80a81f73204d454426fC413CAe455525A7';
+      const tokenBridgeConfig = require('../genesis-configs/base/genesis_token.json')['bridge'][tokenType][tokenId];
+      const {
+        token_pool: tokenPoolAddr,
+        min_checkout_per_request: minCheckoutPerRequest,
+        max_checkout_per_request: maxCheckoutPerRequest,
+        max_checkout_per_day: maxCheckoutPerDay,
+       } = tokenBridgeConfig;
+      const checkoutAmount = 100;
+      const ethAddress = '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1';
+
+      it('cannot open checkout with invalid params: amount < min_checkout_per_request', async () => {
+        const beforeBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${serviceUser}/balance`)
+            .body.toString('utf-8')).result;
+        const beforeTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`).body.toString('utf-8')).result;
+        const body = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: {
+          ref: `/checkout/requests/${serviceUser}/0`,
+          value: {
+            amount: minCheckoutPerRequest - 1,
+            type: tokenType,
+            token_id: tokenId,
+            recipient: ethAddress
           }
+        }}).body.toString('utf-8'));
+        expect(body.code).to.equal(1);
+        if (!(await waitUntilTxFinalized(serverList, _.get(body, 'result.tx_hash')))) {
+          console.error(`Failed to check finalization of tx.`);
         }
-      };
-      await setUpApp('test_billing', serverList, { admin: adminConfig, billing: billingConfig });
+        const checkoutRequest = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/requests/${serviceUser}/0`).body.toString('utf-8')).result;
+        const afterRequestUserBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${serviceUser}/balance`).body.toString('utf-8')).result;
+        const afterRequestTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`)
+            .body.toString('utf-8')).result;
+        expect(checkoutRequest).to.equal(null);
+        expect(afterRequestUserBalance).to.equal(beforeBalance);
+        expect(afterRequestTokenPoolBalance).to.equal(beforeTokenPoolBalance);
+      });
 
-      const server4Addr =
-          parseOrLog(syncRequest('GET', server4 + '/get_address').body.toString('utf-8')).result;
-      const transferRes = parseOrLog(syncRequest('POST', server4 + '/set', {json: {
-        op_list: [
-          {
-            ref: `/transfer/${server4Addr}/billing|test_billing|A/${Date.now()}/value`,
-            value: 100,
-            type: 'SET_VALUE'
-          },
-          {
-            ref: `/transfer/${server4Addr}/billing|test_billing|B/${Date.now()}/value`,
-            value: 100,
-            type: 'SET_VALUE'
+      it('cannot open checkout with invalid params: amount > max_checkout_per_request', async () => {
+        const beforeBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${serviceUser}/balance`)
+            .body.toString('utf-8')).result;
+        const beforeTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`).body.toString('utf-8')).result;
+        const body = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: {
+          ref: `/checkout/requests/${serviceUser}/0`,
+          value: {
+            amount: maxCheckoutPerRequest + 1,
+            type: tokenType,
+            token_id: tokenId,
+            recipient: ethAddress
           }
-        ],
-        nonce: -1,
-        timestamp: Date.now(),
-      }}).body.toString('utf-8')).result;
-      if (!(await waitUntilTxFinalized(serverList, transferRes.tx_hash))) {
-        console.error(`Failed to check finalization of transfer tx.`);
-      }
-    });
+        }}).body.toString('utf-8'));
+        expect(body.code).to.equal(1);
+        if (!(await waitUntilTxFinalized(serverList, _.get(body, 'result.tx_hash')))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+        const checkoutRequest = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/requests/${serviceUser}/0`).body.toString('utf-8')).result;
+        const afterRequestUserBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${serviceUser}/balance`).body.toString('utf-8')).result;
+        const afterRequestTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`)
+            .body.toString('utf-8')).result;
+        expect(checkoutRequest).to.equal(null);
+        expect(afterRequestUserBalance).to.equal(beforeBalance);
+        expect(afterRequestTokenPoolBalance).to.equal(beforeTokenPoolBalance);
+      });
 
-    it('app txs are not charged by transfer', async () => {
-      const balanceBefore = parseOrLog(syncRequest('GET', server2 + userBalancePathA).body.toString('utf-8')).result;
-      const txWithoutBillingRes = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: {
-          ref: '/apps/test_billing/test',
-          value: 'testing app tx',
+      it('cannot open checkout with invalid params: type', async () => {
+        const beforeBalance = parseOrLog(syncRequest('GET',
+        server2 + `/get_value?ref=/accounts/${serviceUser}/balance`)
+            .body.toString('utf-8')).result;
+        const beforeTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`).body.toString('utf-8')).result;
+        const body = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: {
+          ref: `/checkout/requests/${serviceUser}/0`,
+          value: {
+            amount: checkoutAmount,
+            type: 'AIN',
+            token_id: tokenId,
+            recipient: ethAddress
+          }
+        }}).body.toString('utf-8'));
+        expect(body.code).to.equal(1);
+        if (!(await waitUntilTxFinalized(serverList, _.get(body, 'result.tx_hash')))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+        const checkoutRequest = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/requests/${serviceUser}/0`).body.toString('utf-8')).result;
+        const afterRequestUserBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${serviceUser}/balance`).body.toString('utf-8')).result;
+        const afterRequestTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`)
+            .body.toString('utf-8')).result;
+        expect(checkoutRequest).to.equal(null);
+        expect(afterRequestUserBalance).to.equal(beforeBalance);
+        expect(afterRequestTokenPoolBalance).to.equal(beforeTokenPoolBalance);
+      });
+
+      it('cannot open checkout with invalid params: token_id', async () => {
+        const beforeBalance = parseOrLog(syncRequest('GET',
+        server2 + `/get_value?ref=/accounts/${serviceUser}/balance`)
+            .body.toString('utf-8')).result;
+        const beforeTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`).body.toString('utf-8')).result;
+        const body = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: {
+          ref: `/checkout/requests/${serviceUser}/0`,
+          value: {
+            amount: checkoutAmount,
+            type: tokenType,
+            token_id: '',
+            recipient: ethAddress
+          }
+        }}).body.toString('utf-8'));
+        expect(body.code).to.equal(1);
+        if (!(await waitUntilTxFinalized(serverList, _.get(body, 'result.tx_hash')))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+        const checkoutRequest = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/requests/${serviceUser}/0`).body.toString('utf-8')).result;
+        const afterRequestUserBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${serviceUser}/balance`).body.toString('utf-8')).result;
+        const afterRequestTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`)
+            .body.toString('utf-8')).result;
+        expect(checkoutRequest).to.equal(null);
+        expect(afterRequestUserBalance).to.equal(beforeBalance);
+        expect(afterRequestTokenPoolBalance).to.equal(beforeTokenPoolBalance);
+      });
+
+      it('cannot open checkout with invalid params: recipient', async () => {
+        const beforeBalance = parseOrLog(syncRequest('GET',
+        server2 + `/get_value?ref=/accounts/${serviceUser}/balance`)
+            .body.toString('utf-8')).result;
+        const beforeTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`).body.toString('utf-8')).result;
+        const body = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: {
+          ref: `/checkout/requests/${serviceUser}/0`,
+          value: {
+            amount: checkoutAmount,
+            type: tokenType,
+            token_id: tokenId,
+            recipient: ethAddress.toLowerCase()
+          }
+        }}).body.toString('utf-8'));
+        expect(body.code).to.equal(1);
+        if (!(await waitUntilTxFinalized(serverList, _.get(body, 'result.tx_hash')))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+        const checkoutRequest = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/requests/${serviceUser}/0`).body.toString('utf-8')).result;
+        const afterRequestUserBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${serviceUser}/balance`).body.toString('utf-8')).result;
+        const afterRequestTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`)
+            .body.toString('utf-8')).result;
+        expect(checkoutRequest).to.equal(null);
+        expect(afterRequestUserBalance).to.equal(beforeBalance);
+        expect(afterRequestTokenPoolBalance).to.equal(beforeTokenPoolBalance);
+      });
+
+      it('cannot open checkout with insufficient funds', async () => {
+        const beforeBalance = parseOrLog(syncRequest('GET',
+        server2 + `/get_value?ref=/accounts/${serviceUser}/balance`)
+            .body.toString('utf-8')).result;
+        const beforeTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`).body.toString('utf-8')).result;
+        const body = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: {
+          ref: `/checkout/requests/${serviceUser}/0`,
+          value: {
+            amount: beforeBalance + 1,
+            type: tokenType,
+            token_id: tokenId,
+            recipient: ethAddress
+          }
+        }}).body.toString('utf-8'));
+        expect(body.code).to.equal(1);
+        if (!(await waitUntilTxFinalized(serverList, _.get(body, 'result.tx_hash')))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+        const checkoutRequest = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/requests/${serviceUser}/0`).body.toString('utf-8')).result;
+        const afterRequestUserBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${serviceUser}/balance`).body.toString('utf-8')).result;
+        const afterRequestTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`)
+            .body.toString('utf-8')).result;
+        expect(checkoutRequest).to.equal(null);
+        expect(afterRequestUserBalance).to.equal(beforeBalance);
+        expect(afterRequestTokenPoolBalance).to.equal(beforeTokenPoolBalance);
+      });
+
+      it('can open checkout', async () => {
+        const beforeBalance = parseOrLog(syncRequest('GET',
+        server2 + `/get_value?ref=/accounts/${serviceUser}/balance`)
+            .body.toString('utf-8')).result;
+        const beforeTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`).body.toString('utf-8')).result;
+        const body = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: {
+          ref: `/checkout/requests/${serviceUser}/0`,
+          value: {
+            amount: checkoutAmount,
+            type: tokenType,
+            token_id: tokenId,
+            recipient: ethAddress
+          },
+          timestamp: 1628255843548
+        }}).body.toString('utf-8'));
+        expect(body.code).to.equal(0);
+        if (!(await waitUntilTxFinalized(serverList, _.get(body, 'result.tx_hash')))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+        assert.deepEqual(eraseStateGas(_.get(body, 'result.result')), {
+          "func_results": {
+            "_openCheckout": {
+              "op_results": {
+                "0": {
+                  "path": "/checkout/stats/pending/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                },
+                "1": {
+                  "path": "/checkout/stats/pending/total",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                },
+                "2": {
+                  "path": "/transfer/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204/0x20ADd3d38405ebA6338CB9e57a0510DEB8f8e000/1628255843548/value",
+                  "result": {
+                    "func_results": {
+                      "_transfer": {
+                        "op_results": {
+                          "0": {
+                            "path": "/accounts/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204/balance",
+                            "result": {
+                              "code": 0,
+                              "bandwidth_gas_amount": 1
+                            }
+                          },
+                          "1": {
+                            "path": "/accounts/0x20ADd3d38405ebA6338CB9e57a0510DEB8f8e000/balance",
+                            "result": {
+                              "code": 0,
+                              "bandwidth_gas_amount": 1
+                            }
+                          },
+                          "2": {
+                            "path": "/transfer/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204/0x20ADd3d38405ebA6338CB9e57a0510DEB8f8e000/1628255843548/result",
+                            "result": {
+                              "code": 0,
+                              "bandwidth_gas_amount": 1
+                            }
+                          }
+                        },
+                        "code": 0,
+                        "bandwidth_gas_amount": 1000
+                      }
+                    },
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                }
+              },
+              "code": 0,
+              "bandwidth_gas_amount": 0
+            }
+          },
+          "code": 0,
+          "bandwidth_gas_amount": 1,
+          "gas_amount_charged": 'erased',
+          "gas_amount_total": {
+            "bandwidth": {
+              "service": 1007
+            },
+            "state": {
+              "service": 'erased'
+            }
+          },
+          "gas_cost_total": 0
+        });
+        const afterRequestUserBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${serviceUser}/balance`).body.toString('utf-8')).result;
+        const afterRequestTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`)
+            .body.toString('utf-8')).result;
+        const userPendingAmount = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/stats/pending/${serviceUser}`)
+            .body.toString('utf-8')).result;
+        const totalPendingAmount = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/stats/pending/total`)
+            .body.toString('utf-8')).result;
+        expect(afterRequestUserBalance).to.equal(beforeBalance - checkoutAmount);
+        expect(afterRequestTokenPoolBalance).to.equal(beforeTokenPoolBalance + checkoutAmount);
+        expect(userPendingAmount).to.equal(checkoutAmount);
+        expect(totalPendingAmount).to.equal(checkoutAmount);
+      });
+
+      it('cannot close checkout with a non-authorized address', async () => {
+        const body = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: {
+          ref: `/checkout/history/${serviceUser}/0`,
+          value: {
+            request: {
+              amount: checkoutAmount,
+              type: tokenType,
+              token_id: tokenId,
+              recipient: ethAddress
+            },
+            response: {
+              status: 0
+            }
+          }
+        }}).body.toString('utf-8'));
+        expect(body.code).to.equal(1);
+        if (!(await waitUntilTxFinalized(serverList, _.get(body, 'result.tx_hash')))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+        const checkoutHistory = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/history/${serviceUser}/0`).body.toString('utf-8')).result;
+        expect(checkoutHistory).to.equal(null);
+      });
+
+      it('can close a successful checkout with token pool key', async () => {
+        const txBody = {
+          operation: {
+            type: 'SET_VALUE',
+            ref: `/checkout/history/${serviceUser}/0`,
+            value: {
+              request: {
+                amount: checkoutAmount,
+                type: tokenType,
+                token_id: tokenId,
+                recipient: ethAddress
+              },
+              response: {
+                status: 0,
+                tx_hash: '0x6af1ec8d4f0a55bac328cb20336ed0eff46fa6334ebd112147892f1b15aafc8c'
+              }
+            }
+          },
+          timestamp: 1628255843548,
+          nonce: -1
+        };
+        const signature =
+            ainUtil.ecSignTransaction(txBody, Buffer.from('d42f73de4ee706a4891dad643e0a65c0677020dbc2425f585442d0de2c742a44', 'hex'));
+        const res = await client.request('ain_sendSignedTransaction', {
+          tx_body: txBody,
+          signature,
+          protoVer: CURRENT_PROTOCOL_VERSION
+        });
+        assert.deepEqual(eraseStateGas(_.get(res, 'result.result.result', null)), {
+          "func_results": {
+            "_closeCheckout": {
+              "op_results": {
+                "0": {
+                  "path": "/checkout/stats/complete/1628208000000",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                },
+                "1": {
+                  "path": "/checkout/stats/complete/total",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                },
+                "2": {
+                  "path": "/checkout/requests/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204/0",
+                  "result": {
+                    "bandwidth_gas_amount": 1,
+                    "code": 0,
+                    "func_results": {
+                      "_openCheckout": {
+                        "bandwidth_gas_amount": 0,
+                        "code": 0
+                      }
+                    }
+                  }
+                },
+                "3": {
+                  "path": "/checkout/stats/pending/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204",
+                  "result": {
+                    "bandwidth_gas_amount": 1,
+                    "code": 0
+                  }
+                },
+                "4": {
+                  "path": "/checkout/stats/pending/total",
+                  "result": {
+                    "bandwidth_gas_amount": 1,
+                    "code": 0
+                  }
+                }
+              },
+              "code": 0,
+              "bandwidth_gas_amount": 0
+            }
+          },
+          "code": 0,
+          "bandwidth_gas_amount": 1,
+          "gas_amount_charged": 'erased',
+          "gas_amount_total": {
+            "bandwidth": {
+              "service": 6
+            },
+            "state": {
+              "service": 'erased'
+            }
+          },
+          "gas_cost_total": 0
+        });
+        const userPendingAmount = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/stats/pending/${serviceUser}`)
+            .body.toString('utf-8')).result;
+        const totalPendingAmount = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/stats/pending/total`)
+            .body.toString('utf-8')).result;
+        const todayCompleteAmount = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/stats/complete/${CommonUtil.getDayTimestamp(1628255843548)}`)
+            .body.toString('utf-8')).result;
+        const totalCompleteAmount = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/stats/complete/total`)
+            .body.toString('utf-8')).result;
+        expect(userPendingAmount).to.equal(0);
+        expect(totalPendingAmount).to.equal(0);
+        expect(todayCompleteAmount).to.equal(checkoutAmount);
+        expect(totalCompleteAmount).to.equal(checkoutAmount);
+      });
+
+      it('can close a failed checkout and refund with token pool key', async () => {
+        // open checkout
+        const beforeBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${serviceUser}/balance`)
+            .body.toString('utf-8')).result || 0;
+        const beforeTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`)
+            .body.toString('utf-8')).result || 0;
+        const body = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: {
+          ref: `/checkout/requests/${serviceUser}/1`,
+          value: {
+            amount: checkoutAmount,
+            type: tokenType,
+            token_id: tokenId,
+            recipient: ethAddress
+          }
+        }}).body.toString('utf-8'));
+        expect(body.code).to.equal(0);
+        if (!(await waitUntilTxFinalized(serverList, _.get(body, 'result.tx_hash')))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+        expect(_.get(body, 'result.result.code')).to.equal(0);
+        const afterRequestUserBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${serviceUser}/balance`)
+            .body.toString('utf-8')).result || 0;
+        const afterRequestTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`)
+            .body.toString('utf-8')).result || 0;
+        expect(afterRequestUserBalance).to.equal(beforeBalance - checkoutAmount);
+        expect(afterRequestTokenPoolBalance).to.equal(beforeTokenPoolBalance + checkoutAmount);
+        // close failed checkout
+        const txBody = {
+          operation: {
+            type: 'SET_VALUE',
+            ref: `/checkout/history/${serviceUser}/1`,
+            value: {
+              request: {
+                amount: checkoutAmount,
+                type: tokenType,
+                token_id: tokenId,
+                recipient: ethAddress
+              },
+              response: {
+                status: 1,
+                tx_hash: '0x6af1ec8d4f0a55bac328cb20336ed0eff46fa6334ebd112147892f1b15aafc8c',
+                error_message: 'Ethereum tx failed'
+              }
+            }
+          },
+          timestamp: 1628255843548,
+          nonce: -1
+        };
+        const signature =
+            ainUtil.ecSignTransaction(txBody, Buffer.from('d42f73de4ee706a4891dad643e0a65c0677020dbc2425f585442d0de2c742a44', 'hex'));
+        const res = await client.request('ain_sendSignedTransaction', {
+          tx_body: txBody,
+          signature,
+          protoVer: CURRENT_PROTOCOL_VERSION
+        });
+        if (!(await waitUntilTxFinalized(serverList, _.get(res, 'result.result.tx_hash')))) {
+          console.error(`Failed to check finalization of tx.`);
+        }
+        assert.deepEqual(eraseStateGas(_.get(res, 'result.result.result')), {
+          "func_results": {
+            "_closeCheckout": {
+              "op_results": {
+                "0": {
+                  "path": "/transfer/0x20ADd3d38405ebA6338CB9e57a0510DEB8f8e000/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204/1628255843548/value",
+                  "result": {
+                    "func_results": {
+                      "_transfer": {
+                        "op_results": {
+                          "0": {
+                            "path": "/accounts/0x20ADd3d38405ebA6338CB9e57a0510DEB8f8e000/balance",
+                            "result": {
+                              "code": 0,
+                              "bandwidth_gas_amount": 1
+                            }
+                          },
+                          "1": {
+                            "path": "/accounts/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204/balance",
+                            "result": {
+                              "code": 0,
+                              "bandwidth_gas_amount": 1
+                            }
+                          },
+                          "2": {
+                            "path": "/transfer/0x20ADd3d38405ebA6338CB9e57a0510DEB8f8e000/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204/1628255843548/result",
+                            "result": {
+                              "code": 0,
+                              "bandwidth_gas_amount": 1
+                            }
+                          }
+                        },
+                        "code": 0,
+                        "bandwidth_gas_amount": 0
+                      }
+                    },
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                },
+                "1": {
+                  "path": "/checkout/history/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204/1/refund",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                },
+                "2": {
+                  "path": "/checkout/requests/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204/1",
+                  "result": {
+                    "func_results": {
+                      "_openCheckout": {
+                        "code": 0,
+                        "bandwidth_gas_amount": 0
+                      }
+                    },
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                },
+                "3": {
+                  "path": "/checkout/stats/pending/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                },
+                "4": {
+                  "path": "/checkout/stats/pending/total",
+                  "result": {
+                    "code": 0,
+                    "bandwidth_gas_amount": 1
+                  }
+                }
+              },
+              "code": 0,
+              "bandwidth_gas_amount": 0
+            }
+          },
+          "code": 0,
+          "bandwidth_gas_amount": 1,
+          "gas_amount_charged": 'erased',
+          "gas_amount_total": {
+            "bandwidth": {
+              "service": 9
+            },
+            "state": {
+              "service": 'erased'
+            }
+          },
+          "gas_cost_total": 0
+        });
+        const refund = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/history/${serviceUser}/1/refund`).body.toString('utf-8')).result;
+        assert.deepEqual(refund, '/transfer/0x20ADd3d38405ebA6338CB9e57a0510DEB8f8e000/0x01A0980d2D4e418c7F27e1ef539d01A5b5E93204/1628255843548');
+        const refundTransfer = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=${refund}`).body.toString('utf-8')).result;
+        assert.deepEqual(refundTransfer, {
+          "value": 100,
+          "result": {
+            "timestamp": 1628255843548,
+            "tx_hash": "0xbefafa6bb77dc60e4e3856124efff5c122c7d2a56ef305669cdf7f3e1d3aa642",
+            "code": 0
+          }
+        });
+        const afterCloseUserBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${serviceUser}/balance`)
+            .body.toString('utf-8')).result || 0;
+        const afterCloseTokenPoolBalance = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/accounts/${tokenPoolAddr}/balance`)
+            .body.toString('utf-8')).result || 0;
+        const userPendingAmount = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/stats/pending/${serviceUser}`)
+            .body.toString('utf-8')).result;
+        const totalPendingAmount = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/stats/pending/total`)
+            .body.toString('utf-8')).result;
+        const todayCompleteAmount = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/stats/complete/${CommonUtil.getDayTimestamp(1628255843548)}`)
+            .body.toString('utf-8')).result;
+        const totalCompleteAmount = parseOrLog(syncRequest('GET',
+            server2 + `/get_value?ref=/checkout/stats/complete/total`)
+            .body.toString('utf-8')).result;
+        expect(afterCloseUserBalance).to.equal(beforeBalance);
+        expect(afterCloseTokenPoolBalance).to.equal(beforeTokenPoolBalance);
+        expect(userPendingAmount).to.equal(0);
+        expect(totalPendingAmount).to.equal(0);
+        expect(todayCompleteAmount).to.equal(checkoutAmount);
+        expect(totalCompleteAmount).to.equal(checkoutAmount);
+      });
+    });
+  });
+
+  describe('Billing', async () => {
+    let serviceAdmin; // = server1
+    let billingUserA; // = server2
+    let billingUserB; // = server3
+    let userBalancePathA;
+    let userBalancePathB;
+    const billingAccountBalancePathA = '/get_value?ref=/service_accounts/billing/test_billing/A/balance';
+    before(async () => {
+      serviceAdmin =
+          parseOrLog(syncRequest('GET', server1 + '/get_address').body.toString('utf-8')).result;
+      billingUserA =
+          parseOrLog(syncRequest('GET', server2 + '/get_address').body.toString('utf-8')).result;
+      billingUserB =
+          parseOrLog(syncRequest('GET', server3 + '/get_address').body.toString('utf-8')).result;
+      userBalancePathA = `/get_value?ref=/accounts/${billingUserA}/balance`;
+      userBalancePathB = `/get_value?ref=/accounts/${billingUserB}/balance`;
+      const adminConfig = {
+        [serviceAdmin]: true,
+        [billingUserA]: true,
+        [billingUserB]: true
+      };
+      const billingConfig = {
+        A: { 
+          users: {
+            [serviceAdmin]: true,
+            [billingUserA]: true
+          }
+        },
+        B: {
+          users: {
+            [serviceAdmin]: true,
+            [billingUserB]: true
+          }
+        }
+      };
+      await setUpApp('test_billing', serverList, { admin: adminConfig, billing: billingConfig });
+
+      const server4Addr =
+          parseOrLog(syncRequest('GET', server4 + '/get_address').body.toString('utf-8')).result;
+      const transferRes = parseOrLog(syncRequest('POST', server4 + '/set', {json: {
+        op_list: [
+          {
+            ref: `/transfer/${server4Addr}/billing|test_billing|A/${Date.now()}/value`,
+            value: 100,
+            type: 'SET_VALUE'
+          },
+          {
+            ref: `/transfer/${server4Addr}/billing|test_billing|B/${Date.now()}/value`,
+            value: 100,
+            type: 'SET_VALUE'
+          }
+        ],
+        nonce: -1,
+        timestamp: Date.now(),
+      }}).body.toString('utf-8')).result;
+      if (!(await waitUntilTxFinalized(serverList, transferRes.tx_hash))) {
+        console.error(`Failed to check finalization of transfer tx.`);
+      }
+    });
+
+    it('app txs are not charged by transfer', async () => {
+      // NOTE(platfowner): A pre-tx to guarantee that the service state delta of the next tx
+      // is zero.
+      const txPreRes = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: {
+          ref: '/apps/test_billing/test_pre',
+          value: 'testing app tx',
+          gas_price: 1,
+          nonce: -1,
+          timestamp: Date.now(),
+        }
+      }).body.toString('utf-8')).result;
+      if (!(await waitUntilTxFinalized(serverList, txPreRes.tx_hash))) {
+        console.error(`Failed to check finalization of app tx.`);
+      }
+      const balanceBefore = parseOrLog(syncRequest('GET', server2 + userBalancePathA).body.toString('utf-8')).result;
+      const txWithoutBillingRes = parseOrLog(syncRequest('POST', server2 + '/set_value', {json: {
+          ref: '/apps/test_billing/test',
+          value: 'testing app tx',
           gas_price: 1,
           nonce: -1,
           timestamp: Date.now(),
@@ -6737,7 +7267,7 @@ describe('Blockchain Node', () => {
       const tx = parseOrLog(syncRequest('GET', server2 + `/get_transaction?hash=${txRes.tx_hash}`).body.toString('utf-8')).result;
       const gasFeeCollected = parseOrLog(syncRequest(
         'GET',
-        `${server2}/get_value?ref=/gas_fee/collect/${billingUserA}/${tx.number}/${txRes.tx_hash}/amount`
+        `${server2}/get_value?ref=/gas_fee/collect/${tx.number}/${billingUserA}/${txRes.tx_hash}/amount`
       ).body.toString('utf-8')).result;
       assert.deepEqual(
         gasFeeCollected,
@@ -6815,7 +7345,7 @@ describe('Blockchain Node', () => {
       const tx = parseOrLog(syncRequest('GET', server2 + `/get_transaction?hash=${txRes.tx_hash}`).body.toString('utf-8')).result;
       const gasFeeCollected = parseOrLog(syncRequest(
         'GET',
-        `${server2}/get_value?ref=/gas_fee/collect/${billingUserA}/${tx.number}/${txRes.tx_hash}/amount`
+        `${server2}/get_value?ref=/gas_fee/collect/${tx.number}/${billingUserA}/${txRes.tx_hash}/amount`
       ).body.toString('utf-8')).result;
       assert.deepEqual(
         gasFeeCollected,
@@ -6875,7 +7405,7 @@ describe('Blockchain Node', () => {
       const tx = parseOrLog(syncRequest('GET', server2 + `/get_transaction?hash=${txRes.tx_hash}`).body.toString('utf-8')).result;
       const gasFeeCollected = parseOrLog(syncRequest(
         'GET',
-        `${server2}/get_value?ref=/gas_fee/collect/${billingUserA}/${tx.number}/${txRes.tx_hash}/amount`
+        `${server2}/get_value?ref=/gas_fee/collect/${tx.number}/${billingUserA}/${txRes.tx_hash}/amount`
       ).body.toString('utf-8')).result;
       assert.deepEqual(
         gasFeeCollected,
@@ -6980,7 +7510,7 @@ describe('Blockchain Node', () => {
   });
 
   describe('Tx Receipts', () => {
-    it(`records a transaction's receipt`, async () => {
+    it(`records a transaction receipt`, async () => {
       const txSignerAddress = parseOrLog(syncRequest(
           'GET', server1 + '/get_address').body.toString('utf-8')).result;
       const request = {
@@ -6997,32 +7527,17 @@ describe('Blockchain Node', () => {
       }
 
       const receipt = parseOrLog(syncRequest(
-          'GET', server1 + `/get_value?ref=/receipts/${body.result.tx_hash}`)
+          'GET', server1 + `/get_value?ref=${PathUtil.getReceiptPath(body.result.tx_hash)}`)
           .body.toString('utf-8')).result;
       assert.deepEqual(receipt.address, txSignerAddress);
       assert.deepEqual(receipt.exec_result, {
-        bandwidth_gas_amount: 1,
-        code: 0,
-        gas_amount_charged: 0,
-        gas_amount_total: {
-          bandwidth: {
-            app: {
-              test: 1
-            },
-            service: 0
-          },
-          state: {
-            app: {
-              test: 188
-            },
-            service: 0
-          },
-        },
-        gas_cost_total: 0
+        "code": 0,
+        "gas_amount_charged": 0,
+        "gas_cost_total": 0
       });
     });
 
-    it(`removes an old transaction's receipt`, async () => {
+    it(`removes an old transaction receipt`, async () => {
       const MAX_BLOCK_NUMBERS_FOR_RECEIPTS = 100;
       let lastBlockNumber = getLastBlockNumber(server1);
       if (lastBlockNumber <= MAX_BLOCK_NUMBERS_FOR_RECEIPTS) {
@@ -7037,7 +7552,7 @@ describe('Blockchain Node', () => {
       }
       for (const tx of oldBlock.transactions) {
         const receipt = parseOrLog(syncRequest(
-          'GET', server1 + `/get_value?ref=/receipts/${tx.hash}`)
+          'GET', server1 + `/get_value?ref=${PathUtil.getReceiptPath(tx.hash)}`)
           .body.toString('utf-8')).result;
         assert.deepEqual(receipt, null);
       }
@@ -7074,14 +7589,14 @@ describe('Blockchain Node', () => {
       // Failed tx's receipt is in state
       const txHash = body.result.tx_hash;
       const receipt = parseOrLog(syncRequest(
-        'GET', server2 + `/get_value?ref=/receipts/${txHash}`).body.toString('utf-8')).result;
+        'GET', server2 + `/get_value?ref=${PathUtil.getReceiptPath(txHash)}`).body.toString('utf-8')).result;
       expect(receipt).to.not.equal(null);
-      assert.deepEqual(receipt.exec_result, body.result.result);
+      assert.deepEqual(receipt.exec_result, DB.trimExecutionResult(body.result.result));
 
       // Failed tx's gas fees have been collected
       const blockNumber = receipt.block_number;
       const gasFeeCollected = parseOrLog(syncRequest(
-        'GET', server2 + `/get_value?ref=/gas_fee/collect/${server1Address}/${blockNumber}/${txHash}/amount`
+        'GET', server2 + `/get_value?ref=/gas_fee/collect/${blockNumber}/${server1Address}/${txHash}/amount`
       ).body.toString('utf-8')).result;
       assert.deepEqual(gasFeeCollected, body.result.result.gas_cost_total);
 
diff --git a/integration/sharding.test.js b/integration/sharding.test.js
index 5a92a546a..ca0cf5e85 100644
--- a/integration/sharding.test.js
+++ b/integration/sharding.test.js
@@ -32,6 +32,7 @@ const {
   waitForNewBlocks,
   waitUntilNodeSyncs,
   waitUntilTxFinalized,
+  waitUntilNetworkIsReady,
   setUpApp,
 } = require('../unittest/test-util');
 
@@ -254,16 +255,16 @@ describe('Sharding', async () => {
     await setUpApp('afan', parentServerList, { admin: { [shardOwnerAddr]: true } });
     
     tracker_proc = startServer(TRACKER_SERVER, 'tracker server', ENV_VARIABLES[1], true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(3000);
     server1_proc = startServer(APP_SERVER, 'server1', ENV_VARIABLES[2], true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(10000);
     await waitUntilShardReporterStarts();
     server2_proc = startServer(APP_SERVER, 'server2', ENV_VARIABLES[3], true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(3000);
     server3_proc = startServer(APP_SERVER, 'server3', ENV_VARIABLES[4], true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(3000);
     server4_proc = startServer(APP_SERVER, 'server4', ENV_VARIABLES[5], true);
-    await CommonUtil.sleep(2000);
+    await CommonUtil.sleep(3000); // Before shard reporting begins
   });
 
   after(() => {
@@ -360,8 +361,9 @@ describe('Sharding', async () => {
     });
   });
 
-  describe('Child chain initialization', () => {
+  describe('Shard chain initialization', () => {
     before(async () => {
+      await waitUntilNetworkIsReady(shardServerList);
       await setUpApp('afan', shardServerList, { admin: { [shardOwnerAddr]: true } });
     });
     
@@ -463,10 +465,10 @@ describe('Sharding', async () => {
         const reportsBefore = parseOrLog(syncRequest(
             'GET', parentServer + `/get_value?ref=${sharding.sharding_path}/.shard/proof_hash_map`)
           .body.toString('utf-8'));
-        console.log(`Shutting down server[0]...`);
+        console.log(`        --> Shutting down server[0]...`);
         server1_proc.kill();
         await waitForNewBlocks(server2, sharding.reporting_period);
-        console.log(`Restarting server[0]...`);
+        console.log(`        --> Restarting server[0]...`);
         server1_proc = startServer(APP_SERVER, 'server1', ENV_VARIABLES[2]);
         await waitForNewBlocks(server2, sharding.reporting_period * 2);
         await waitUntilNodeSyncs(server1);
@@ -1543,7 +1545,7 @@ describe('Sharding', async () => {
                 "bandwidth_gas_amount": 1
               },
             },
-            "gas_amount_charged": 1548,
+            "gas_amount_charged": 0,
             "gas_amount_total": {
               "bandwidth": {
                 "app": {
@@ -1553,9 +1555,9 @@ describe('Sharding', async () => {
               },
               "state": {
                 "app": {
-                  "test": 2874
+                  "test": 4422
                 },
-                "service": 1548
+                "service": 0
               }
             },
             "gas_cost_total": 0
@@ -2083,7 +2085,7 @@ describe('Sharding', async () => {
           "code": 0,
           "func_results": {
             "_updateLatestShardReport": {
-              "code": "SUCCESS",
+              "code": 0,
               "bandwidth_gas_amount": 0,
               "op_results": {
                 "0": {
@@ -2150,7 +2152,7 @@ describe('Sharding', async () => {
               "code": 0,
               "func_results": {
                 "_updateLatestShardReport": {
-                  "code": "SUCCESS",
+                  "code": 0,
                   "bandwidth_gas_amount": 0,
                   "op_results": {
                     "0": {
@@ -2169,7 +2171,7 @@ describe('Sharding', async () => {
               "code": 0,
               "func_results": {
                 "_updateLatestShardReport": {
-                  "code": "SUCCESS",
+                  "code": 0,
                   "bandwidth_gas_amount": 0,
                 }
               },
diff --git a/json_rpc/index.js b/json_rpc/index.js
index 5ceb5f5a6..ef724d5f9 100644
--- a/json_rpc/index.js
+++ b/json_rpc/index.js
@@ -8,6 +8,7 @@ const {
   TX_BYTES_LIMIT,
   BATCH_TX_LIST_SIZE_LIMIT,
   NETWORK_ID,
+  CHAIN_ID,
   BlockchainNodeStates,
   ReadDbOperations,
   PredefinedDbPaths,
@@ -374,35 +375,40 @@ module.exports = function getMethods(node, p2pServer, minProtocolVersion, maxPro
     },
 
     // Network API
-    net_listening: function(args, done) {
+    net_listening: function (args, done) {
       const peerCount = Object.keys(p2pServer.inbound).length;
-      done(null, addProtocolVersion({result: !!peerCount}));
+      done(null, addProtocolVersion({ result: !!peerCount }));
     },
 
-    net_peerCount: function(args, done) {
+    net_peerCount: function (args, done) {
       const peerCount = Object.keys(p2pServer.inbound).length;
-      done(null, addProtocolVersion({result: peerCount}));
+      done(null, addProtocolVersion({ result: peerCount }));
     },
 
-    net_syncing: function(args, done) {
+    net_syncing: function (args, done) {
       // TODO(liayoo): Return { starting, latest } with block numbers
       // if the node is currently syncing.
-      done(null, addProtocolVersion(
-          {result: p2pServer.node.state === BlockchainNodeStates.SYNCING}));
+      done(null, addProtocolVersion({
+        result: p2pServer.node.state === BlockchainNodeStates.SYNCING
+      }));
+    },
+
+    net_getNetworkId: function (args, done) {
+      done(null, addProtocolVersion({ result: NETWORK_ID }));
     },
 
-    net_getNetworkId: function(args, done) {
-      done(null, addProtocolVersion({result: NETWORK_ID}));
+    net_getChainId: function (args, done) {
+      done(null, addProtocolVersion({ result: CHAIN_ID }));
     },
 
-    net_consensusStatus: function(args, done) {
+    net_consensusStatus: function (args, done) {
       const result = p2pServer.consensus.getStatus();
-      done(null, addProtocolVersion({result}));
+      done(null, addProtocolVersion({ result }));
     },
 
-    net_rawConsensusStatus: function(args, done) {
+    net_rawConsensusStatus: function (args, done) {
       const result = p2pServer.consensus.getRawStatus();
-      done(null, addProtocolVersion({result}));
+      done(null, addProtocolVersion({ result }));
     }
   };
 };
diff --git a/loadtest/load_tester.sh b/loadtest/load_tester.sh
index 7ae97c5db..6f2c97b7d 100644
--- a/loadtest/load_tester.sh
+++ b/loadtest/load_tester.sh
@@ -12,7 +12,7 @@ sleep 5
 LOCAL=true node $BASEDIR/../client/index.js > $BASEDIR/log1.txt &
 PID2=$!
 sleep 10
-P2P_PORT=5020 PORT=8081 STAKE=250 node $BASEDIR/../client/index.js > $BASEDIR/log2.txt &
+P2P_PORT=5020 PORT=8081 STAKE=100000 node $BASEDIR/../client/index.js > $BASEDIR/log2.txt &
 PID3=$!
 
 sleep 20
diff --git a/node/index.js b/node/index.js
index 937a4b08f..ddd516eda 100644
--- a/node/index.js
+++ b/node/index.js
@@ -28,6 +28,7 @@ const {
 } = require('../common/constants');
 const FileUtil = require('../common/file-util');
 const CommonUtil = require('../common/common-util');
+const PathUtil = require('../common/path-util');
 const Blockchain = require('../blockchain');
 const TransactionPool = require('../tx-pool');
 const StateManager = require('../db/state-manager');
@@ -416,12 +417,14 @@ class BlockchainNode {
   removeOldReceipts(blockNumber, db) {
     const LOG_HEADER = 'removeOldReceipts';
     if (blockNumber > MAX_BLOCK_NUMBERS_FOR_RECEIPTS) {
-      const receiptsPrefixFullPath = DB.getFullPath(
-          [PredefinedDbPaths.RECEIPTS], PredefinedDbPaths.VALUES_ROOT);
       const oldBlock = this.bc.getBlockByNumber(blockNumber - MAX_BLOCK_NUMBERS_FOR_RECEIPTS);
       if (oldBlock) {
         oldBlock.transactions.forEach((tx) => {
-          db.writeDatabase([...receiptsPrefixFullPath, tx.hash], null);
+          db.writeDatabase(
+              [
+                PredefinedDbPaths.VALUES_ROOT,
+                ...CommonUtil.parsePath(PathUtil.getReceiptPath(tx.hash))
+              ], null);
         });
       } else {
         logger.error(
@@ -436,13 +439,13 @@ class BlockchainNode {
     for (const block of blockList) {
       this.removeOldReceipts(block.number, db);
       if (block.number > 0) {
-        if (!db.executeTransactionList(block.last_votes, true)) {
+        if (!db.executeTransactionList(block.last_votes, true, false, 0, block.timestamp)) {
           logger.error(`[${LOG_HEADER}] Failed to execute last_votes of block: ` +
               `${JSON.stringify(block, null, 2)}`);
           return false;
         }
       }
-      if (!db.executeTransactionList(block.transactions, block.number === 0, true, block.number)) {
+      if (!db.executeTransactionList(block.transactions, block.number === 0, false, block.number, block.timestamp)) {
         logger.error(`[${LOG_HEADER}] Failed to execute transactions of block: ` +
             `${JSON.stringify(block, null, 2)}`);
         return false;
@@ -532,13 +535,13 @@ class BlockchainNode {
 
     this.removeOldReceipts(block.number, db);
     if (block.number > 0) {
-      if (!db.executeTransactionList(block.last_votes, true)) {
+      if (!db.executeTransactionList(block.last_votes, true, false, block.number, block.timestamp)) {
         logger.error(`[${LOG_HEADER}] Failed to execute last_votes (${block.number})`);
         // NOTE(liayoo): Quick fix for the problem. May be fixed by deleting the block files.
         process.exit(1);
       }
     }
-    if (!db.executeTransactionList(block.transactions, block.number === 0, true, block.number)) {
+    if (!db.executeTransactionList(block.transactions, block.number === 0, false, block.number, block.timestamp)) {
       logger.error(`[${LOG_HEADER}] Failed to execute transactions (${block.number})`)
       // NOTE(liayoo): Quick fix for the problem. May be fixed by deleting the block files.
       process.exit(1);
@@ -574,7 +577,8 @@ class BlockchainNode {
         // NOTE(liayoo): Quick fix for the problem. May be fixed by deleting the block files.
         process.exit(1);
       }
-      // NOTE(minsulee2): Deal with the case the only genesis block was generated.
+      // NOTE(liayoo): we don't have the votes for the last block, so remove it and try to
+      //               receive from peers.
       if (deleteLastBlock && number > 0 && number === numBlockFiles - 1) {
         lastBlockWithoutProposal = block;
         this.bc.deleteBlock(lastBlockWithoutProposal);
diff --git a/p2p/index.js b/p2p/index.js
index 0c3c3fce0..e9fed0dff 100644
--- a/p2p/index.js
+++ b/p2p/index.js
@@ -6,6 +6,7 @@ const logger = require('../logger')('P2P_CLIENT');
 const { ConsensusStates } = require('../consensus/constants');
 const VersionUtil = require('../common/version-util');
 const {
+  HOSTING_ENV,
   PORT,
   P2P_PORT,
   TRACKER_WS_ADDR,
@@ -13,8 +14,7 @@ const {
   BlockchainNodeStates,
   DEFAULT_MAX_OUTBOUND,
   DEFAULT_MAX_INBOUND,
-  MAX_OUTBOUND_LIMIT,
-  MAX_INBOUND_LIMIT
+  NETWORK_ID,
 } = require('../common/constants');
 const { sleep } = require('../common/common-util');
 const {
@@ -25,7 +25,8 @@ const {
   verifySignedMessage,
   checkTimestamp,
   closeSocketSafe,
-  encapsulateMessage
+  encapsulateMessage,
+  isValidNetworkId
 } = require('./util');
 
 const RECONNECT_INTERVAL_MS = 5 * 1000;  // 5 seconds
@@ -52,12 +53,10 @@ class P2pClient {
   // maxOutbound is for now limited equal or less than 2.
   // maxInbound is a rest of connection after maxOutbound is set.
   initConnections() {
-    const numOutbound = process.env.MAX_OUTBOUND ?
+    this.maxOutbound = process.env.MAX_OUTBOUND ?
         Number(process.env.MAX_OUTBOUND) : DEFAULT_MAX_OUTBOUND;
-    const numInbound = process.env.MAX_INBOUND ?
+    this.maxInbound = process.env.MAX_INBOUND ?
         Number(process.env.MAX_INBOUND) : DEFAULT_MAX_INBOUND;
-    this.maxOutbound = Math.min(numOutbound, MAX_OUTBOUND_LIMIT);
-    this.maxInbound = Math.min(numInbound, MAX_INBOUND_LIMIT);
   }
 
   getConnectionStatus() {
@@ -94,14 +93,16 @@ class P2pClient {
   }
 
   getNetworkStatus() {
+    const intIp = this.server.getInternalIp();
     const extIp = this.server.getExternalIp();
-    const url = new URL(`ws://${extIp}:${P2P_PORT}`);
-    const p2pUrl = url.toString();
-    url.protocol = 'http:';
-    url.port = PORT;
-    const clientApiUrl = url.toString();
-    url.pathname = 'json-rpc';
-    const jsonRpcUrl = url.toString();
+    const intUrl = new URL(`ws://${intIp}:${P2P_PORT}`);
+    const extUrl = new URL(`ws://${extIp}:${P2P_PORT}`);
+    const p2pUrl = HOSTING_ENV === 'comcom' ? intUrl.toString() : extUrl.toString();
+    extUrl.protocol = 'http:';
+    extUrl.port = PORT;
+    const clientApiUrl = extUrl.toString();
+    extUrl.pathname = 'json-rpc';
+    const jsonRpcUrl = extUrl.toString();
     return {
       ip: extIp,
       p2p: {
@@ -271,9 +272,16 @@ class P2pClient {
     const LOG_HEADER = 'setClientSidePeerEventHandlers';
     socket.on('message', (message) => {
       const parsedMessage = JSON.parse(message);
+      const networkId = _.get(parsedMessage, 'networkId');
+      const address = getAddressFromSocket(this.outbound, socket);
+      if (!isValidNetworkId(networkId)) {
+        logger.error(`The given network ID(${networkId}) of the node(${address}) is MISSING or ` +
+          `DIFFERENT from mine(${NETWORK_ID}). Disconnect the connection.`);
+        closeSocketSafe(this.outbound, socket);
+        return;
+      }
       const dataProtoVer = _.get(parsedMessage, 'dataProtoVer');
       if (!VersionUtil.isValidProtocolVersion(dataProtoVer)) {
-        const address = getAddressFromSocket(this.outbound, socket);
         logger.error(`The data protocol version of the node(${address}) is MISSING or ` +
               `INAPPROPRIATE. Disconnect the connection.`);
         closeSocketSafe(this.outbound, socket);
diff --git a/p2p/server.js b/p2p/server.js
index 794791a3f..83d331775 100644
--- a/p2p/server.js
+++ b/p2p/server.js
@@ -18,8 +18,6 @@ const {
   DATA_PROTOCOL_VERSION,
   P2P_PORT,
   HOSTING_ENV,
-  COMCOM_HOST_EXTERNAL_IP,
-  COMCOM_HOST_INTERNAL_IP_MAP,
   MessageTypes,
   BlockchainNodeStates,
   PredefinedDbPaths,
@@ -34,7 +32,8 @@ const {
   FunctionTypes,
   NativeFunctionIds,
   LIGHTWEIGHT,
-  FeatureFlags
+  FeatureFlags,
+  NETWORK_ID
 } = require('../common/constants');
 const CommonUtil = require('../common/common-util');
 const {
@@ -49,7 +48,8 @@ const {
   verifySignedMessage,
   checkTimestamp,
   closeSocketSafe,
-  encapsulateMessage
+  encapsulateMessage,
+  isValidNetworkId
 } = require('./util');
 const PathUtil = require('../common/path-util');
 
@@ -116,6 +116,10 @@ class P2pServer {
     return this.node.account.private_key;
   }
 
+  getInternalIp() {
+    return this.node.ipAddrInternal;
+  }
+
   getExternalIp() {
     return this.node.ipAddrExternal;
   }
@@ -294,19 +298,11 @@ class P2pServer {
           process.exit(0);
         });
       } else if (HOSTING_ENV === 'comcom') {
-        let ipAddr = null;
         if (internal) {
-          const hostname = _.toLower(os.hostname());
-          logger.info(`Hostname: ${hostname}`);
-          ipAddr = COMCOM_HOST_INTERNAL_IP_MAP[hostname];
+          return ip.address();
         } else {
-          ipAddr = COMCOM_HOST_EXTERNAL_IP;
+          return publicIp.v4();
         }
-        if (ipAddr) {
-          return ipAddr;
-        }
-        logger.error(`Failed to get ${internal ? 'internal' : 'external'} ip address.`);
-        process.exit(0);
       } else if (HOSTING_ENV === 'local') {
         return ip.address();
       } else {
@@ -358,12 +354,19 @@ class P2pServer {
     socket.on('message', (message) => {
       try {
         const parsedMessage = JSON.parse(message);
-        const dataProtoVer = _.get(parsedMessage, 'dataProtoVer');
+        const networkId = _.get(parsedMessage, 'networkId');
         const address = getAddressFromSocket(this.inbound, socket);
+        if (!isValidNetworkId(networkId)) {
+          logger.error(`The given network ID(${networkId}) of the node(${address}) is MISSING or ` +
+            `DIFFERENT from mine(${NETWORK_ID}). Disconnect the connection.`);
+          closeSocketSafe(this.inbound, socket);
+          return;
+        }
+        const dataProtoVer = _.get(parsedMessage, 'dataProtoVer');
         if (!VersionUtil.isValidProtocolVersion(dataProtoVer)) {
           logger.error(`The data protocol version of the node(${address}) is MISSING or ` +
               `INAPPROPRIATE. Disconnect the connection.`);
-          closeSocketSafe(this.outbound, socket);
+          closeSocketSafe(this.inbound, socket);
           return;
         }
         if (!checkTimestamp(_.get(parsedMessage, 'timestamp'))) {
diff --git a/p2p/util.js b/p2p/util.js
index fdec15ddb..66da756a1 100644
--- a/p2p/util.js
+++ b/p2p/util.js
@@ -11,6 +11,7 @@ const {
   CURRENT_PROTOCOL_VERSION,
   DATA_PROTOCOL_VERSION,
   P2P_MESSAGE_TIMEOUT_MS,
+  NETWORK_ID
 } = require('../common/constants');
 const CommonUtil = require('../common/common-util');
 
@@ -95,6 +96,7 @@ function encapsulateMessage(type, dataObj) {
     data: dataObj,
     protoVer: CURRENT_PROTOCOL_VERSION,
     dataProtoVer: DATA_PROTOCOL_VERSION,
+    networkId: NETWORK_ID,
     timestamp: Date.now()
   };
   return message;
@@ -113,6 +115,14 @@ function checkTimestamp(timestamp) {
   }
 }
 
+function isValidNetworkId(networkId) {
+  if (networkId !== NETWORK_ID) {
+    return false;
+  } else {
+    return true;
+  }
+}
+
 module.exports = {
   getAddressFromSocket,
   removeSocketConnectionIfExists,
@@ -121,5 +131,6 @@ module.exports = {
   verifySignedMessage,
   closeSocketSafe,
   checkTimestamp,
-  encapsulateMessage
+  encapsulateMessage,
+  isValidNetworkId
 };
diff --git a/package.json b/package.json
index 52a24ddb8..cba2cf4f6 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "ain-blockchain",
   "description": "AI Network Blockchain",
-  "version": "0.9.0",
+  "version": "0.9.1",
   "private": true,
   "license": "MIT",
   "author": "dev@ainetwork.ai",
@@ -18,11 +18,13 @@
     "lint": "eslint --ext js -c .eslintrc.json .",
     "loadtest": "sh loadtest/load_tester.sh",
     "test_integration": "./node_modules/mocha/bin/mocha --timeout 640000 \"integration/*.test.js\"",
-    "test_integration_blockchain": "./node_modules/mocha/bin/mocha --timeout 160000 integration/blockchain.test.js",
-    "test_integration_consensus": "./node_modules/mocha/bin/mocha --timeout 160000 integration/consensus.test.js",
-    "test_integration_dapp": "./node_modules/mocha/bin/mocha --timeout 160000 integration/afan_dapp.test.js",
+    "test_integration_blockchain": "./node_modules/mocha/bin/mocha --timeout 640000 integration/blockchain.test.js",
+    "test_integration_consensus": "./node_modules/mocha/bin/mocha --timeout 640000 integration/consensus.test.js",
+    "test_integration_dapp": "./node_modules/mocha/bin/mocha --timeout 640000 integration/afan_dapp.test.js",
     "test_integration_node": "./node_modules/mocha/bin/mocha --timeout 640000 integration/node.test.js",
-    "test_integration_sharding": "./node_modules/mocha/bin/mocha --timeout 320000 integration/sharding.test.js",
+    "test_integration_sharding": "./node_modules/mocha/bin/mocha --timeout 640000 integration/sharding.test.js",
+    "test_integration_he_protocol": "./node_modules/mocha/bin/mocha --timeout 640000 integration/he_protocol.test.js",
+    "test_integration_he_sharding": "./node_modules/mocha/bin/mocha --timeout 640000 integration/he_sharding.test.js",
     "test_unit": "MIN_NUM_VALIDATORS=1 STATE_TREE_BYTES_LIMIT=20000000 ./node_modules/mocha/bin/mocha --timeout 160000 \"unittest/*.test.js\"",
     "test_unit_block_pool": "MIN_NUM_VALIDATORS=1 ./node_modules/mocha/bin/mocha --timeout 160000 unittest/block-pool.test.js",
     "test_unit_blockchain": "MIN_NUM_VALIDATORS=1 ./node_modules/mocha/bin/mocha --timeout 160000 unittest/blockchain.test.js",
@@ -36,6 +38,9 @@
     "test_unit_state_manager": "./node_modules/mocha/bin/mocha --timeout 160000 unittest/state-manager.test.js",
     "test_unit_state_node": "./node_modules/mocha/bin/mocha --timeout 160000 unittest/state-node.test.js",
     "test_unit_state_util": "./node_modules/mocha/bin/mocha --timeout 160000 unittest/state-util.test.js",
+    "test_unit_radix_child_map": "./node_modules/mocha/bin/mocha --timeout 160000 unittest/radix-child-map.test.js",
+    "test_unit_radix_node": "./node_modules/mocha/bin/mocha --timeout 160000 unittest/radix-node.test.js",
+    "test_unit_radix_tree": "./node_modules/mocha/bin/mocha --timeout 160000 unittest/radix-tree.test.js",
     "test_unit_tx": "MIN_NUM_VALIDATORS=1 ./node_modules/mocha/bin/mocha --timeout 160000 unittest/transaction.test.js",
     "test_unit_tx_pool": "MIN_NUM_VALIDATORS=1 ./node_modules/mocha/bin/mocha --timeout 160000 unittest/tx-pool.test.js",
     "tracker": "npm run clean & node ./tracker-server/index.js"
diff --git a/port_list_macos.sh b/port_list_macos.sh
index 1f3007018..5d88e7492 100644
--- a/port_list_macos.sh
+++ b/port_list_macos.sh
@@ -1,2 +1,4 @@
+#!/bin/bash
+
 # Gets a list of the system port numbers in use for MacOS
 sudo lsof -i -P -n | grep LISTEN
diff --git a/reset_blockchain_gcp.sh b/reset_blockchain_gcp.sh
index d4ab9363b..b3a7cc804 100644
--- a/reset_blockchain_gcp.sh
+++ b/reset_blockchain_gcp.sh
@@ -1,7 +1,7 @@
-#!/bin/sh
+#!/bin/bash
 
 if [[ "$#" -lt 3 ]]; then
-    echo "Usage: sh reset_blockchain_gcp.sh dev lia 0"
+    echo "Usage: bash reset_blockchain_gcp.sh dev lia 0"
     exit
 fi
 
diff --git a/restart_node_gcp.sh b/restart_node_gcp.sh
new file mode 100644
index 000000000..3dd31d639
--- /dev/null
+++ b/restart_node_gcp.sh
@@ -0,0 +1,156 @@
+#!/bin/bash
+
+if [[ "$#" -lt 4 ]] || [[ "$#" -gt 4 ]]; then
+    printf "Usage: bash restart_node_gcp.sh [dev|staging|spring|summer] <Shard Index> <Node Index> [fast|full]\n"
+    printf "Example: bash restart_node_gcp.sh spring 0 0 fast\n"
+    exit
+fi
+
+# 1. Configure env vars (GENESIS_CONFIGS_DIR, TRACKER_WS_ADDR, ACCOUNT_INDEX, ...)
+printf "\n#### [Step 1] Configure env vars ####\n\n"
+
+export GENESIS_CONFIGS_DIR=genesis-configs/testnet
+if [[ "$1" = 'spring' ]]; then
+    export TRACKER_WS_ADDR=ws://35.221.137.80:5000
+elif [[ "$1" = 'summer' ]]; then
+    export TRACKER_WS_ADDR=ws://35.194.172.106:5000
+elif [[ "$1" = 'staging' ]]; then
+    export TRACKER_WS_ADDR=ws://35.221.150.73:5000
+elif [[ "$1" = 'dev' ]]; then
+    if [[ "$2" = 0 ]]; then
+        export TRACKER_WS_ADDR=ws://34.80.184.73:5000  # dev-tracker-ip
+    elif [[ "$2" = 1 ]]; then
+        export TRACKER_WS_ADDR=ws://35.187.153.22:5000  # dev-shard-1-tracker-ip
+    elif [[ "$2" = 2 ]]; then
+        export TRACKER_WS_ADDR=ws://34.80.203.104:5000  # dev-shard-2-tracker-ip
+    elif [[ "$2" = 3 ]]; then
+        export TRACKER_WS_ADDR=ws://35.189.174.17:5000  # dev-shard-3-tracker-ip
+    elif [[ "$2" = 4 ]]; then
+        export TRACKER_WS_ADDR=ws://35.221.164.158:5000  # dev-shard-4-tracker-ip
+    elif [[ "$2" = 5 ]]; then
+        export TRACKER_WS_ADDR=ws://35.234.46.65:5000  # dev-shard-5-tracker-ip
+    elif [[ "$2" = 6 ]]; then
+        export TRACKER_WS_ADDR=ws://35.221.210.171:5000  # dev-shard-6-tracker-ip
+    elif [[ "$2" = 7 ]]; then
+        export TRACKER_WS_ADDR=ws://34.80.222.121:5000  # dev-shard-7-tracker-ip
+    elif [[ "$2" = 8 ]]; then
+        export TRACKER_WS_ADDR=ws://35.221.200.95:5000  # dev-shard-8-tracker-ip
+    elif [[ "$2" = 9 ]]; then
+        export TRACKER_WS_ADDR=ws://34.80.216.199:5000  # dev-shard-9-tracker-ip
+    elif [[ "$2" = 10 ]]; then
+        export TRACKER_WS_ADDR=ws://34.80.161.85:5000  # dev-shard-10-tracker-ip
+    elif [[ "$2" = 11 ]]; then
+        export TRACKER_WS_ADDR=ws://35.194.239.169:5000  # dev-shard-11-tracker-ip
+    elif [[ "$2" = 12 ]]; then
+        export TRACKER_WS_ADDR=ws://35.185.156.22:5000  # dev-shard-12-tracker-ip
+    elif [[ "$2" = 13 ]]; then
+        export TRACKER_WS_ADDR=ws://35.229.247.143:5000  # dev-shard-13-tracker-ip
+    elif [[ "$2" = 14 ]]; then
+        export TRACKER_WS_ADDR=ws://35.229.226.47:5000  # dev-shard-14-tracker-ip
+    elif [[ "$2" = 15 ]]; then
+        export TRACKER_WS_ADDR=ws://35.234.61.23:5000  # dev-shard-15-tracker-ip
+    elif [[ "$2" = 16 ]]; then
+        export TRACKER_WS_ADDR=ws://34.80.66.41:5000  # dev-shard-16-tracker-ip
+    elif [[ "$2" = 17 ]]; then
+        export TRACKER_WS_ADDR=ws://35.229.143.18:5000  # dev-shard-17-tracker-ip
+    elif [[ "$2" = 18 ]]; then
+        export TRACKER_WS_ADDR=ws://35.234.58.137:5000  # dev-shard-18-tracker-ip
+    elif [[ "$2" = 19 ]]; then
+        export TRACKER_WS_ADDR=ws://34.80.249.104:5000  # dev-shard-19-tracker-ip
+    elif [[ "$2" = 20 ]]; then
+        export TRACKER_WS_ADDR=ws://35.201.248.92:5000  # dev-shard-20-tracker-ip
+    else
+        printf "Invalid <Shard Index> argument: $2\n"
+        exit
+    fi
+    if [[ "$2" -gt 0 ]]; then
+        # Create a genesis_params.json
+        export GENESIS_CONFIGS_DIR="genesis-configs/shard_$2"
+        mkdir -p "./$GENESIS_CONFIGS_DIR"
+        node > "./$GENESIS_CONFIGS_DIR/genesis_params.json" <<EOF
+        const data = require('./genesis-configs/testnet/genesis_params.json');
+        data.blockchain.TRACKER_WS_ADDR = '$TRACKER_WS_ADDR';
+        data.consensus.MIN_NUM_VALIDATORS = 3;
+        console.log(JSON.stringify(data, null, 2));
+EOF
+    fi
+else
+    printf "Invalid <Project/Season> argument: $1\n"
+    exit
+fi
+
+printf "TRACKER_WS_ADDR=$TRACKER_WS_ADDR\n"
+printf "GENESIS_CONFIGS_DIR=$GENESIS_CONFIGS_DIR\n"
+
+if [[ "$3" -lt 0 ]] || [[ "$3" -gt 4 ]]; then
+    printf "Invalid <Node Index> argument: $3\n"
+    exit
+fi
+
+export ACCOUNT_INDEX="$3"
+printf "ACCOUNT_INDEX=$ACCOUNT_INDEX\n"
+
+if [[ "$4" != 'fast' ]] && [[ "$4" != 'full' ]]; then
+    printf "Invalid <Sync Mode> argument: $2\n"
+    exit
+fi
+
+export SYNC_MODE="$4"
+printf "SYNC_MODE=$SYNC_MODE\n"
+
+export DEBUG=false
+export CONSOLE_LOG=false
+export ENABLE_DEV_SET_CLIENT_API=false
+export ENABLE_TX_SIG_VERIF_WORKAROUND=false
+export ENABLE_GAS_FEE_WORKAROUND=true
+export LIGHTWEIGHT=false
+export STAKE=100000
+export BLOCKCHAIN_DATA_DIR="/home/ain_blockchain_data"
+
+# 2. Kill the existing node server 
+printf "\n#### [Step 2] Kill the existing node server ####\n\n"
+
+KILL_CMD="sudo killall node"
+printf "KILL_CMD='$KILL_CMD'\n\n"
+eval $KILL_CMD
+sleep 10
+
+# 3. Restart the node server
+printf "\n#### [Step 3] Restart the node server ####\n\n"
+
+MAX_OLD_SPACE_SIZE_MB=6000
+
+START_CMD="nohup node --async-stack-traces --max-old-space-size=$MAX_OLD_SPACE_SIZE_MB client/index.js >/dev/null 2>error_logs.txt &"
+printf "START_CMD='$START_CMD'\n"
+eval $START_CMD
+
+# 4. Wait until the node server catches up
+printf "\n#### [Step 4] Wait until the node server catches up ####\n\n"
+
+SECONDS=0
+loopCount=0
+
+generate_post_data()
+{
+  cat <<EOF
+  {"method":"$1","params":{"protoVer":"0.8.0"},"jsonrpc":"2.0","id":"1"}
+EOF
+}
+
+while :
+do
+    healthCheck=$(curl -m 20 -X GET -H "Content-Type: application/json" "http://localhost:8080/health_check")
+    printf "\nhealthCheck = ${healthCheck}\n"
+    lastBlockNumber=$(curl -m 20 -X POST -H "Content-Type: application/json" --data "$(generate_post_data 'ain_getRecentBlockNumber')" "http://localhost:8080/json-rpc" | jq -r '.result.result')
+    printf "\nlastBlockNumber = ${lastBlockNumber}\n"
+    if [[ "$healthCheck" = "true" ]]; then
+        printf "\nBlockchain Node server is synced & running!\n"
+        printf "\nTime it took to sync in seconds: $SECONDS\n"
+        break
+    fi
+    ((loopCount++))
+    printf "\nLoop count: ${loopCount}\n"
+    sleep 20
+done
+
+printf "\n* << Node server successfully deployed! ***************************************\n\n"
diff --git a/restart_tracker_gcp.sh b/restart_tracker_gcp.sh
new file mode 100644
index 000000000..a0e58ea2a
--- /dev/null
+++ b/restart_tracker_gcp.sh
@@ -0,0 +1,51 @@
+#!/bin/bash
+
+if [[ "$#" -lt 1 ]] || [[ "$#" -gt 1 ]]; then
+    printf "Usage: bash restart_tracker_gcp.sh <Number of Nodes>\n"
+    printf "Example: bash restart_tracker_gcp.sh 5\n"
+    exit
+fi
+
+# 1. Configure env vars
+printf "\n#### [Step 1] Configure env vars ####\n\n"
+
+NUM_NODES="$1"
+
+# 2. Kill the existing tracker server 
+printf "\n#### [Step 2] Kill the existing tracker server ####\n\n"
+
+KILL_CMD="sudo killall node"
+printf "KILL_CMD='$KILL_CMD'\n\n"
+eval $KILL_CMD
+sleep 10
+
+# 3. Restart the tracker server
+printf "\n#### [Step 3] Restart the tracker server ####\n\n"
+
+export CONSOLE_LOG=false 
+
+START_CMD="nohup node --async-stack-traces tracker-server/index.js >/dev/null 2>error_logs.txt &"
+printf "START_CMD='$START_CMD'\n"
+eval $START_CMD
+
+# 4. Wait until the tracker server catches up
+printf "\n#### [Step 4] Wait until the tracker server catches up ####\n\n"
+
+SECONDS=0
+loopCount=0
+
+while :
+do
+    numAliveNodes=$(curl -m 20 -X GET -H "Content-Type: application/json" "http://localhost:8080/network_status" | jq -r '.numAliveNodes')
+    printf "\nnumAliveNodes = ${numAliveNodes}\n"
+    if [[ "$numAliveNodes" = "$NUM_NODES" ]]; then
+        printf "\nBlockchain Tracker server is running!\n"
+        printf "\nTime it took to sync in seconds: $SECONDS\n"
+        break
+    fi
+    ((loopCount++))
+    printf "\nLoop count: ${loopCount}\n"
+    sleep 20
+done
+
+printf "\n* << Tracker server successfully deployed! ************************************\n\n"
diff --git a/setup_blockchain_ubuntu.sh b/setup_blockchain_ubuntu.sh
index ef34718e8..d1fd39098 100644
--- a/setup_blockchain_ubuntu.sh
+++ b/setup_blockchain_ubuntu.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 echo 'Installing NodeJS..'
 sudo apt update
diff --git a/setup_monitoring_gcp.sh b/setup_monitoring_gcp.sh
index 27cec41cf..9a3deacaa 100644
--- a/setup_monitoring_gcp.sh
+++ b/setup_monitoring_gcp.sh
@@ -1,8 +1,8 @@
-#!/bin/sh
+#!/bin/bash
 
 if [[ "$#" -lt 1 ]]; then
-    echo "Usage: sh setup_monitoring_gcp.sh [dev|staging|spring|summer]"
-    echo "Example: sh setup_monitoring_gcp.sh dev"
+    echo "Usage: bash setup_monitoring_gcp.sh [dev|staging|spring|summer]"
+    echo "Example: bash setup_monitoring_gcp.sh dev"
     exit
 fi
 
diff --git a/setup_monitoring_ubuntu.sh b/setup_monitoring_ubuntu.sh
index edb4b7090..d40c2819e 100644
--- a/setup_monitoring_ubuntu.sh
+++ b/setup_monitoring_ubuntu.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 echo 'Installing NodeJS..'
 sudo apt update
diff --git a/start_monitoring_gcp.sh b/start_monitoring_gcp.sh
index 74bdaecfb..c97a2d1cc 100644
--- a/start_monitoring_gcp.sh
+++ b/start_monitoring_gcp.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 echo 'Starting up Prometheus..'
 cd prometheus
diff --git a/start_node_genesis_gcp.sh b/start_node_genesis_gcp.sh
index 590842239..51a762c70 100644
--- a/start_node_genesis_gcp.sh
+++ b/start_node_genesis_gcp.sh
@@ -1,8 +1,8 @@
-#!/bin/sh
+#!/bin/bash
 
 if [[ "$#" -lt 2 ]]; then
-    echo "Usage: sh start_node_genesis_gcp.sh [dev|staging|spring|summer] <Shard Index> <Node Index>"
-    echo "Example: sh start_node_genesis_gcp.sh spring 0 0"
+    echo "Usage: bash start_node_genesis_gcp.sh [dev|staging|spring|summer] <Shard Index> <Node Index>"
+    echo "Example: bash start_node_genesis_gcp.sh spring 0 0"
     exit
 fi
 
diff --git a/start_node_incremental_gcp.sh b/start_node_incremental_gcp.sh
index 8f8c24657..850170711 100644
--- a/start_node_incremental_gcp.sh
+++ b/start_node_incremental_gcp.sh
@@ -1,8 +1,8 @@
-#!/bin/sh
+#!/bin/bash
 
 if [[ "$#" -lt 4 ]] || [[ "$#" -gt 4 ]]; then
-    printf "Usage: sh start_node_incremental_gcp.sh [dev|staging|spring|summer] <Shard Index> <Node Index> [fast|full]\n"
-    printf "Example: sh start_node_incremental_gcp.sh spring 0 0 fast\n"
+    printf "Usage: bash start_node_incremental_gcp.sh [dev|staging|spring|summer] <Shard Index> <Node Index> [fast|full]\n"
+    printf "Example: bash start_node_incremental_gcp.sh spring 0 0 fast\n"
     exit
 fi
 
@@ -142,11 +142,11 @@ printf "\n#### [Step 5] Kill old node server ####\n\n"
 KILL_CMD="sudo killall node"
 printf "KILL_CMD='$KILL_CMD'\n\n"
 eval $KILL_CMD
+sleep 10
 
 # 6. Start a new node server
 printf "\n#### [Step 6] Start new node server ####\n\n"
 
-sleep 10
 MAX_OLD_SPACE_SIZE_MB=6000
 
 START_CMD="nohup node --async-stack-traces --max-old-space-size=$MAX_OLD_SPACE_SIZE_MB client/index.js >/dev/null 2>error_logs.txt &"
diff --git a/start_servers_afan_local.sh b/start_servers_afan_local.sh
index eb12b56c2..15230edd5 100755
--- a/start_servers_afan_local.sh
+++ b/start_servers_afan_local.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+
 # PARENT CHAIN
 CONSOLE_LOG=true BLOCKCHAIN_DATA_DIR=~/ain_blockchain_data node ./tracker-server/index.js &
 sleep 5
diff --git a/start_servers_local.sh b/start_servers_local.sh
index 3f0a76ca0..85032396d 100755
--- a/start_servers_local.sh
+++ b/start_servers_local.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+
 # PARENT CHAIN
 BLOCKCHAIN_DATA_DIR=~/ain_blockchain_data node ./tracker-server/index.js &
 sleep 5
diff --git a/start_tracker_genesis_gcp.sh b/start_tracker_genesis_gcp.sh
index a1c2a601a..c53092684 100644
--- a/start_tracker_genesis_gcp.sh
+++ b/start_tracker_genesis_gcp.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 echo 'Killing jobs..'
 killall node
diff --git a/start_tracker_incremental_gcp.sh b/start_tracker_incremental_gcp.sh
index 71343f1f5..5d38620cd 100644
--- a/start_tracker_incremental_gcp.sh
+++ b/start_tracker_incremental_gcp.sh
@@ -1,8 +1,8 @@
-#!/bin/sh
+#!/bin/bash
 
 if [[ "$#" -lt 1 ]] || [[ "$#" -gt 1 ]]; then
-    printf "Usage: sh start_tracker_incremental_gcp.sh <Number of Nodes>\n"
-    printf "Example: sh start_tracker_incremental_gcp.sh 5\n"
+    printf "Usage: bash start_tracker_incremental_gcp.sh <Number of Nodes>\n"
+    printf "Example: bash start_tracker_incremental_gcp.sh 5\n"
     exit
 fi
 
@@ -44,11 +44,11 @@ printf "\n#### [Step 5] Kill old tracker server ####\n\n"
 KILL_CMD="sudo killall node"
 printf "KILL_CMD='$KILL_CMD'\n\n"
 eval $KILL_CMD
+sleep 10
 
 # 6. Start new tracker server
 printf "\n#### [Step 6] Start new tracker server ####\n\n"
 
-sleep 10
 export CONSOLE_LOG=false 
 
 START_CMD="nohup node --async-stack-traces tracker-server/index.js >/dev/null 2>error_logs.txt &"
diff --git a/stop_servers_local.sh b/stop_servers_local.sh
index f9ccbd0c2..f014f6d6d 100755
--- a/stop_servers_local.sh
+++ b/stop_servers_local.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+
 killall -9 node # SIGKILL
 rm -rf ~/ain_blockchain_data/
 BASEDIR=$(dirname "$0")
diff --git a/tools/checkout/config_gcp.js b/tools/checkout/config_gcp.js
new file mode 100644
index 000000000..05a19c224
--- /dev/null
+++ b/tools/checkout/config_gcp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  endpointUrl: "http://dev-node.ainetwork.ai:8080",
+  userAddr: "0x09A0d53FDf1c36A131938eb379b98910e55EEfe1",
+  userPrivateKey: "ee0b1315d446e5318eb6eb4e9d071cd12ef42d2956d546f9acbdc3b75c469640",
+  recipientAddr: "0x09A0d53FDf1c36A131938eb379b98910e55EEfe1",
+  tokenPoolAddr: "0x20ADd3d38405ebA6338CB9e57a0510DEB8f8e000",
+  tokenPoolPrivateKey: "REDACTED",
+  checkoutId: "0",
+  tokenAmount: 100
+};
\ No newline at end of file
diff --git a/tools/checkout/config_local.js b/tools/checkout/config_local.js
new file mode 100644
index 000000000..88f69e3b6
--- /dev/null
+++ b/tools/checkout/config_local.js
@@ -0,0 +1,10 @@
+module.exports = {
+  endpointUrl: "http://localhost:8081",
+  userAddr: "0x09A0d53FDf1c36A131938eb379b98910e55EEfe1",
+  userPrivateKey: "ee0b1315d446e5318eb6eb4e9d071cd12ef42d2956d546f9acbdc3b75c469640",
+  recipientAddr: "0x09A0d53FDf1c36A131938eb379b98910e55EEfe1",
+  tokenPoolAddr: "0x20ADd3d38405ebA6338CB9e57a0510DEB8f8e000",
+  tokenPoolPrivateKey: "REDACTED",
+  checkoutId: "0",
+  tokenAmount: 100
+};
\ No newline at end of file
diff --git a/tools/checkout/sendCloseCheckoutTx.js b/tools/checkout/sendCloseCheckoutTx.js
new file mode 100644
index 000000000..604d0e5e9
--- /dev/null
+++ b/tools/checkout/sendCloseCheckoutTx.js
@@ -0,0 +1,63 @@
+const path = require('path');
+const { signAndSendTx, confirmTransaction } = require('../util');
+let config = {};
+
+function buildCloseCheckoutTxBody(fromAddr, tokenAmount, checkoutId, failed = false) {
+  const response = {
+    tx_hash: '0xETH_TX_HASH'
+  };
+  if (failed) {
+    response.status = 'FAILURE';
+    response.error_message = 'Ethereum tx failed..'
+  } else {
+    response.status = 0;
+  }
+  return {
+    operation: {
+      type: 'SET_VALUE',
+      ref: `/checkout/history/${fromAddr}/${checkoutId}`,
+      value: {
+        request: {
+          amount: tokenAmount,
+          type: 'ETH',
+          token_id: '0xB16c0C80a81f73204d454426fC413CAe455525A7',
+          recipient: config.recipientAddr
+        },
+        response
+      },
+      is_global: true,
+    },
+    timestamp: Date.now(),
+    nonce: -1
+  }
+}
+
+async function sendTransaction(failed) {
+  console.log('\n*** sendTransaction():');
+  const timestamp = Date.now();
+  const txBody = buildCloseCheckoutTxBody(config.userAddr, config.tokenAmount, config.checkoutId, failed);
+  console.log(`txBody: ${JSON.stringify(txBody, null, 2)}`);
+
+  const txInfo = await signAndSendTx(config.endpointUrl, txBody, config.tokenPoolPrivateKey);
+  console.log(`txInfo: ${JSON.stringify(txInfo, null, 2)}`);
+  if (!txInfo.success) {
+    console.log(`Close checkout transaction failed.`);
+    process.exit(0);
+  }
+  await confirmTransaction(config.endpointUrl, timestamp, txInfo.txHash);
+}
+
+async function processArguments() {
+  if (process.argv.length !== 3 && process.argv.length !== 4) {
+    usage();
+  }
+  config = require(path.resolve(__dirname, process.argv[2]));
+  await sendTransaction(process.argv[3] === '--failed');
+}
+
+function usage() {
+  console.log('\nExample commandlines:\n  node sendCloseCheckoutTx.js config_local.js [--failed]\n')
+  process.exit(0)
+}
+
+processArguments();
diff --git a/tools/checkout/sendOpenCheckoutTx.js b/tools/checkout/sendOpenCheckoutTx.js
new file mode 100644
index 000000000..3da73ba09
--- /dev/null
+++ b/tools/checkout/sendOpenCheckoutTx.js
@@ -0,0 +1,51 @@
+const path = require('path');
+const { signAndSendTx, confirmTransaction } = require('../util');
+let config = {};
+
+function buildOpenCheckoutTxBody(fromAddr, tokenAmount, checkoutId) {
+  return {
+    operation: {
+      type: 'SET_VALUE',
+      ref: `/checkout/requests/${fromAddr}/${checkoutId}`,
+      value: {
+        amount: tokenAmount,
+        type: 'ETH',
+        token_id: '0xB16c0C80a81f73204d454426fC413CAe455525A7',
+        recipient: config.recipientAddr
+      },
+      is_global: true,
+    },
+    timestamp: Date.now(),
+    nonce: -1
+  }
+}
+
+async function sendTransaction() {
+  console.log('\n*** sendTransaction():');
+  const timestamp = Date.now();
+  const txBody = buildOpenCheckoutTxBody(config.userAddr, config.tokenAmount, config.checkoutId);
+  console.log(`txBody: ${JSON.stringify(txBody, null, 2)}`);
+
+  const txInfo = await signAndSendTx(config.endpointUrl, txBody, config.userPrivateKey);
+  console.log(`txInfo: ${JSON.stringify(txInfo, null, 2)}`);
+  if (!txInfo.success) {
+    console.log(`Open checkout transaction failed.`);
+    process.exit(0);
+  }
+  await confirmTransaction(config.endpointUrl, timestamp, txInfo.txHash);
+}
+
+async function processArguments() {
+  if (process.argv.length !== 3) {
+    usage();
+  }
+  config = require(path.resolve(__dirname, process.argv[2]));
+  await sendTransaction();
+}
+
+function usage() {
+  console.log('\nExample commandlines:\n  node sendOpenCheckoutTx.js config_local.js\n')
+  process.exit(0)
+}
+
+processArguments();
diff --git a/tools/cicd/deployment.js b/tools/cicd/deployment.js
index 909ff2df8..f918b64de 100644
--- a/tools/cicd/deployment.js
+++ b/tools/cicd/deployment.js
@@ -101,7 +101,7 @@ const main = async () => {
   const insightVersion = getVersion(`${INSIGHT}/src/data/constants`, 'const.js', 'VERSION', 1);
   const faucetVersion = getVersionFromAinJs(ainJsVersion, FAUCET);
   const connectVersion = faucetVersion;
-  const pipelineVersion = getVersion(`${PIPELINE}/constants`, 'const.js', 'AIN_PROTOCOL_VERSION', 1);
+  const pipelineVersion = getVersion(`${PIPELINE}/constants`, 'const.js', 'AIN_PROTOCOL_VERSION', 3);
   const dataVersion = getVersionFromAinJs(ainJsVersion, DATA);
   const exporterVersion = GPT2Version;
 
@@ -125,7 +125,8 @@ const main = async () => {
   // Compare versions and set color
   const currentRowNumber = (await sheet.getRows()).length + 1;
   await sheet.loadCells(`E${currentRowNumber}:L${currentRowNumber}`);
-  Object.keys(CELL_DICTIONARY).forEach(repo => {
+  for (const repo of Object.keys(CELL_DICTIONARY)) {
+    if (!semver.valid(row[repo])) continue;
     const isLower = semver.lt(row[repo], row.min);
     if (isLower) {
       const latestAinJsCell = sheet.getCellByA1(`${CELL_DICTIONARY[repo]}${currentRowNumber}`);
@@ -135,7 +136,7 @@ const main = async () => {
         blue: 0
       };
     }
-  });
+  }
   await sheet.saveUpdatedCells();
 }
 
diff --git a/tools/he-health-care/config_local.js b/tools/he-health-care/config_local.js
new file mode 100644
index 000000000..3efd95c1f
--- /dev/null
+++ b/tools/he-health-care/config_local.js
@@ -0,0 +1,9 @@
+module.exports = {
+  serviceOwnerAddr: '0xb2585543Cfcfb79CF73a1a14b2DfBC411913940F',
+  serviceOwnerPrivateKey: 'd910c1835eaa89f15452aa3f0bd95f61fb9a04464150e37d617a40ed0071558c',
+  userAddr: '0x282cc0b0c38Bcf800F4CD620F5476F9960837E3A',
+  userPrivateKey: 'd64c90a4c5c07418c3db8da0cb786f341ba59fa10550babfbd40c8f6f8c57b81',
+  endpointUrl: 'http://localhost:8081',
+  healthCareAppName: 'he_health_care',
+  healthCareServiceName: 'https://ainetwork.ai',
+};
diff --git a/tools/he-health-care/sendCreateAppTx.js b/tools/he-health-care/sendCreateAppTx.js
new file mode 100644
index 000000000..448675d37
--- /dev/null
+++ b/tools/he-health-care/sendCreateAppTx.js
@@ -0,0 +1,29 @@
+const { signAndSendTx } = require('../util');
+const { healthCareAppName, endpointUrl, serviceOwnerPrivateKey, serviceOwnerAddr } = require('./config_local');
+
+function buildCreateAppTxBody(appName, timestamp) {
+  return {
+    operation: {
+      type: 'SET_VALUE',
+      ref: `/manage_app/${appName}/create/${timestamp}`,
+      value: {
+        admin: {
+          [serviceOwnerAddr]: true,
+        },
+      },
+    },
+    timestamp,
+    nonce: -1,
+  };
+}
+
+async function main() {
+  // TODO(sanghee): Support 'node sendCreateAppTx.js <config_filename>' and check args
+  const createHealthCareAppTxBody = buildCreateAppTxBody(healthCareAppName, Date.now());
+  const createResult = await signAndSendTx(endpointUrl, createHealthCareAppTxBody, serviceOwnerPrivateKey);
+  if (!createResult.success) {
+    throw Error(`Can't create health care app (${JSON.stringify(createResult, null, 2)})`);
+  }
+}
+
+main();
diff --git a/tools/he-health-care/sendSetFunctionTx.js b/tools/he-health-care/sendSetFunctionTx.js
new file mode 100644
index 000000000..c8c5f0270
--- /dev/null
+++ b/tools/he-health-care/sendSetFunctionTx.js
@@ -0,0 +1,41 @@
+const { signAndSendTx } = require('../util');
+const {
+  healthCareAppName,
+  endpointUrl,
+  serviceOwnerPrivateKey,
+  healthCareServiceName,
+} = require('./config_local');
+
+const workerTriggerUrl = 'http://localhost:3000/trigger';
+
+function buildSetFunctionTxBody(appName, timestamp) {
+  return {
+    operation: {
+      type: 'SET_FUNCTION',
+      ref: `/apps/${appName}/tasks/$key`,
+      value: {
+        '.function': {
+          'he-trigger': {
+            function_type: 'REST',
+            event_listener: workerTriggerUrl,
+            service_name: healthCareServiceName,
+            function_id: 'he-trigger',
+          },
+        },
+      },
+    },
+    timestamp,
+    nonce: -1,
+  };
+}
+
+async function main() {
+  // TODO(sanghee): Support 'node sendSetFunctionTx.js <config_filename>' and check args
+  const setFunctionTxBody = buildSetFunctionTxBody(healthCareAppName, Date.now());
+  const setFunctionResult = await signAndSendTx(endpointUrl, setFunctionTxBody, serviceOwnerPrivateKey);
+  if (!setFunctionResult.success) {
+    throw Error(`Can't set function (${JSON.stringify(setFunctionResult, null, 2)})`);
+  }
+}
+
+main();
diff --git a/tools/he-health-care/sendSetRuleTx.js b/tools/he-health-care/sendSetRuleTx.js
new file mode 100644
index 000000000..5be7e2fc5
--- /dev/null
+++ b/tools/he-health-care/sendSetRuleTx.js
@@ -0,0 +1,29 @@
+const { signAndSendTx } = require('../util');
+const { healthCareAppName, endpointUrl, serviceOwnerPrivateKey } = require('./config_local');
+
+function buildSetRuleTxBody(appName, timestamp) {
+  return {
+    operation: {
+      type: 'SET_RULE',
+      ref: `/apps/${appName}`,
+      value: {
+        '.rule': {
+          'write': true,
+        },
+      },
+    },
+    timestamp,
+    nonce: -1,
+  };
+}
+
+async function main() {
+  // TODO(sanghee): Support 'node sendSetRuleTx.js <config_filename>' and check args
+  const setRuleTxBody = buildSetRuleTxBody(healthCareAppName, Date.now());
+  const setRuleResult = await signAndSendTx(endpointUrl, setRuleTxBody, serviceOwnerPrivateKey);
+  if (!setRuleResult.success) {
+    throw Error(`Can't set rule (${JSON.stringify(setRuleResult, null, 2)})`);
+  }
+}
+
+main();
diff --git a/tools/he-health-care/sendTaskRequestTx.js b/tools/he-health-care/sendTaskRequestTx.js
new file mode 100644
index 000000000..2a89eb569
--- /dev/null
+++ b/tools/he-health-care/sendTaskRequestTx.js
@@ -0,0 +1,26 @@
+const { signAndSendTx } = require('../util');
+const { healthCareAppName, endpointUrl, userPrivateKey } = require('./config_local');
+
+function buildSetValueTxBody(appName, timestamp) {
+  const dummy = 'a'.repeat(4 * 1024); // 8KB
+  return {
+    operation: {
+      type: 'SET_VALUE',
+      ref: `/apps/${appName}/tasks/${timestamp}`,
+      value: dummy,
+    },
+    timestamp,
+    nonce: -1,
+  };
+}
+
+async function main() {
+  // TODO(sanghee): Support 'node sendTaskRequestTx.js <config_filename>' and check args
+  const setValueTxBody = buildSetValueTxBody(healthCareAppName, Date.now());
+  const setValueResult = await signAndSendTx(endpointUrl, setValueTxBody, userPrivateKey);
+  if (!setValueResult.success) {
+    throw Error(`Can't set value (${JSON.stringify(setValueResult, null, 2)})`);
+  }
+}
+
+main();
diff --git a/tools/he-health-care/startMockWorker.js b/tools/he-health-care/startMockWorker.js
new file mode 100644
index 000000000..a74eca18a
--- /dev/null
+++ b/tools/he-health-care/startMockWorker.js
@@ -0,0 +1,22 @@
+const express = require('express');
+const app = express();
+const port = 3000;
+
+app.use(express.json());
+app.use((req, res, next) => {
+  const method = req.method;
+  const url = req.url;
+  const status = res.statusCode;
+  const log = `${method}:${url} ${status}`;
+  console.log(log);
+  next();
+});
+
+app.post('/trigger', (req, res) => {
+  res.send('Triggered!');
+  console.log(`Body: ${JSON.stringify(req.body, null, 2)}`);
+});
+
+app.listen(port, () => {
+  console.log(`App listening at http://localhost:${port}`);
+});
diff --git a/tools/util.js b/tools/util.js
index de18406f2..803fddb8a 100644
--- a/tools/util.js
+++ b/tools/util.js
@@ -1,12 +1,15 @@
 const _ = require('lodash');
 const axios = require('axios');
-const { CURRENT_PROTOCOL_VERSION } = require('../common/constants');
+const {
+  CURRENT_PROTOCOL_VERSION,
+  CHAIN_ID
+} = require('../common/constants');
 const CommonUtil = require('../common/common-util');
 
 // FIXME(minsulee2): this is duplicated function see: ./common/network-util.js
 function signAndSendTx(endpointUrl, txBody, privateKey) {
   console.log('\n*** signAndSendTx():');
-  const {txHash, signedTx} = CommonUtil.signTransaction(txBody, privateKey);
+  const { txHash, signedTx } = CommonUtil.signTransaction(txBody, privateKey, CHAIN_ID);
   console.log(`signedTx: ${JSON.stringify(signedTx, null, 2)}`);
   console.log(`txHash: ${txHash}`);
   console.log('Sending transaction...');
diff --git a/tracker-server/index.js b/tracker-server/index.js
index f935b8303..0a890167a 100755
--- a/tracker-server/index.js
+++ b/tracker-server/index.js
@@ -8,7 +8,10 @@ const { v4: uuidv4 } = require('uuid');
 const disk = require('diskusage');
 const os = require('os');
 const v8 = require('v8');
-const { CURRENT_PROTOCOL_VERSION } = require('../common/constants');
+const {
+  CURRENT_PROTOCOL_VERSION,
+  MAX_NUM_PEER_CANDIDATES_AT_ONCE
+} = require('../common/constants');
 const CommonUtil = require('../common/common-util');
 const logger = require('../logger')('TRACKER_SERVER');
 
@@ -120,11 +123,7 @@ server.on('connection', (ws) => {
     logger.info(`\n<< Update from node [${abbrAddr(nodeInfo.address)}]`);
     logger.debug(`: ${JSON.stringify(nodeInfo, null, 2)}`);
 
-    let newManagedPeerInfoList = [];
-    if (nodeInfo.networkStatus.connectionStatus.outgoingPeers.length <
-        nodeInfo.networkStatus.connectionStatus.maxOutbound) {
-      newManagedPeerInfoList = assignRandomPeers(getPeerCandidates(nodeInfo.address));
-    }
+    const newManagedPeerInfoList = assignRandomPeers(nodeInfo);
     const msgToNode = {
       newManagedPeerInfoList,
       numLivePeers: getNumAliveNodes() - 1   // except for me.
@@ -164,34 +163,33 @@ function getNumNodes() {
   return Object.keys(peerNodes).length;
 }
 
-function assignRandomPeers(candidates) {
-  if (_.isEmpty(candidates)) {
-    return [];
-  }
-
-  const shuffled = _.shuffle(candidates);
-  if (shuffled.length > 1) {
-    return [shuffled.pop(), shuffled.pop()];
+function getMaxNumberOfNewPeers(nodeInfo) {
+  const numOfCandidates = nodeInfo.networkStatus.connectionStatus.maxOutbound -
+      nodeInfo.networkStatus.connectionStatus.outgoingPeers.length;
+  if (numOfCandidates >= MAX_NUM_PEER_CANDIDATES_AT_ONCE) {
+    return MAX_NUM_PEER_CANDIDATES_AT_ONCE;
   } else {
-    return shuffled;
+    return numOfCandidates;
   }
 }
 
-function getPeerCandidates(myself) {
-  const candidates = [];
-  Object.values(peerNodes).forEach(nodeInfo => {
-    if (nodeInfo.address !== myself &&
-        nodeInfo.isAlive === true &&
-        !nodeInfo.networkStatus.connectionStatus.incomingPeers.includes(myself) &&
-        nodeInfo.networkStatus.connectionStatus.incomingPeers.length <
-            nodeInfo.networkStatus.connectionStatus.maxInbound) {
-      candidates.push({
-        address: nodeInfo.address,
-        url: nodeInfo.networkStatus.p2p.url
-      });
-    }
-  });
-  return candidates;
+function assignRandomPeers(nodeInfo) {
+  const maxNumberOfNewPeers = getMaxNumberOfNewPeers(nodeInfo);
+  if (maxNumberOfNewPeers) {
+    const candidates = Object.values(peerNodes)
+    .filter(peer =>
+      peer.address !== nodeInfo.address &&
+      peer.isAlive === true &&
+      !peer.networkStatus.connectionStatus.incomingPeers.includes(nodeInfo.address) &&
+      peer.networkStatus.connectionStatus.incomingPeers.length <
+          peer.networkStatus.connectionStatus.maxInbound)
+    .map(peer => ({ address: peer.address, url: peer.networkStatus.p2p.url }));
+
+    const shuffled = _.shuffle(candidates);
+    return shuffled.slice(0, maxNumberOfNewPeers);
+  } else {
+    return [];
+  }
 }
 
 function printNodesInfo() {
diff --git a/tx-pool/transaction.js b/tx-pool/transaction.js
index eecfd8287..f6a959d19 100644
--- a/tx-pool/transaction.js
+++ b/tx-pool/transaction.js
@@ -5,6 +5,7 @@ const {
   ENABLE_TX_SIG_VERIF_WORKAROUND,
   ENABLE_GAS_FEE_WORKAROUND,
   WriteDbOperations,
+  CHAIN_ID
 } = require('../common/constants');
 const CommonUtil = require('../common/common-util');
 
@@ -51,7 +52,7 @@ class Transaction {
     // A devel method for bypassing the transaction verification.
     let signature = '';
     if (!txBody.address) {
-      const signed = CommonUtil.signTransaction(txBody, privateKey);
+      const signed = CommonUtil.signTransaction(txBody, privateKey, CHAIN_ID);
       const sig = _.get(signed, 'signedTx.signature', null);
       if (!sig) {
         return null;
diff --git a/unittest/block-pool.test.js b/unittest/block-pool.test.js
index ef65a2956..22470c071 100644
--- a/unittest/block-pool.test.js
+++ b/unittest/block-pool.test.js
@@ -24,8 +24,8 @@ describe("BlockPool", () => {
 
   function createAndAddBlock(node, blockPool, lastBlock, number, epoch) {
     const block = Block.create(
-        lastBlock.hash, [], [], number, epoch, '', node.account.address,
-        {[node.account.address]: { [PredefinedDbPaths.STAKE]: 100000, [PredefinedDbPaths.PROPOSAL_RIGHT]: true } }, 0, 0);
+        lastBlock.hash, [], {}, [], number, epoch, '', node.account.address,
+        {[node.account.address]: { [PredefinedDbPaths.CONSENSUS_STAKE]: 100000, [PredefinedDbPaths.CONSENSUS_PROPOSAL_RIGHT]: true } }, 0, 0);
     const proposal = getTransaction(node, {
         operation: {
           type: 'SET_VALUE',
@@ -33,7 +33,7 @@ describe("BlockPool", () => {
           value: {
             number: block.number,
             epoch: block.epoch,
-            validators: { [node.account.address]: { [PredefinedDbPaths.STAKE]: 100000, [PredefinedDbPaths.PROPOSAL_RIGHT]: true } },
+            validators: { [node.account.address]: { [PredefinedDbPaths.CONSENSUS_STAKE]: 100000, [PredefinedDbPaths.CONSENSUS_PROPOSAL_RIGHT]: true } },
             total_at_stake: 100000,
             proposer: node.account.address,
             block_hash: block.hash
@@ -50,10 +50,11 @@ describe("BlockPool", () => {
     const voteTx = getTransaction(node, {
       operation: {
         type: 'SET_VALUE',
-        ref: `/consensus/number/${block.number}/vote`,
+        ref: `/consensus/number/${block.number}/${block.hash}/vote`,
         value: {
           block_hash: block.hash,
-          stake: 100000
+          stake: 100000,
+          is_against: false
         }
       },
       gas_price: 1
@@ -65,8 +66,8 @@ describe("BlockPool", () => {
     const lastBlock = node1.bc.lastBlock();
     const addr = node1.account.address;
     const block = Block.create(
-        lastBlock.hash, [], [], lastBlock.number + 1, lastBlock.epoch + 1, '', addr,
-        {[addr]: { [PredefinedDbPaths.STAKE]: 100000, [PredefinedDbPaths.PROPOSAL_RIGHT]: true }}, 0, 0);
+        lastBlock.hash, [], {}, [], lastBlock.number + 1, lastBlock.epoch + 1, '', addr,
+        {[addr]: { [PredefinedDbPaths.CONSENSUS_STAKE]: 100000, [PredefinedDbPaths.CONSENSUS_PROPOSAL_RIGHT]: true }}, 0, 0);
     const proposalTx = getTransaction(node1, {
         operation: {
           type: 'SET_VALUE',
@@ -74,7 +75,7 @@ describe("BlockPool", () => {
           value: {
             number: block.number,
             epoch: block.epoch,
-            validators: {[addr]: { [PredefinedDbPaths.STAKE]: 100000, [PredefinedDbPaths.PROPOSAL_RIGHT]: true } },
+            validators: {[addr]: { [PredefinedDbPaths.CONSENSUS_STAKE]: 100000, [PredefinedDbPaths.CONSENSUS_PROPOSAL_RIGHT]: true } },
             total_at_stake: 100000,
             proposer: addr,
             block_hash: block.hash
@@ -94,8 +95,8 @@ describe("BlockPool", () => {
     const addr = node1.account.address;
     const lastBlock = node1.bc.lastBlock();
     const block = Block.create(
-        lastBlock.hash, [], [], lastBlock.number + 1, lastBlock.epoch + 1, '', addr,
-        {[addr]: { [PredefinedDbPaths.STAKE]: 100000, [PredefinedDbPaths.PROPOSAL_RIGHT]: true }}, 0, 0);
+        lastBlock.hash, [], {}, [], lastBlock.number + 1, lastBlock.epoch + 1, '', addr,
+        {[addr]: { [PredefinedDbPaths.CONSENSUS_STAKE]: 100000, [PredefinedDbPaths.CONSENSUS_PROPOSAL_RIGHT]: true }}, 0, 0);
     const proposalTx = getTransaction(node1, {
         operation: {
           type: 'SET_VALUE',
@@ -103,7 +104,7 @@ describe("BlockPool", () => {
           value: {
             number: block.number,
             epoch: block.epoch,
-            validators: {[addr]: { [PredefinedDbPaths.STAKE]: 100000, [PredefinedDbPaths.PROPOSAL_RIGHT]: true } },
+            validators: {[addr]: { [PredefinedDbPaths.CONSENSUS_STAKE]: 100000, [PredefinedDbPaths.CONSENSUS_PROPOSAL_RIGHT]: true } },
             total_at_stake: 100000,
             proposer: addr,
             block_hash: block.hash
diff --git a/unittest/blockchain.test.js b/unittest/blockchain.test.js
index 1decd0f19..b43c4def5 100644
--- a/unittest/blockchain.test.js
+++ b/unittest/blockchain.test.js
@@ -36,7 +36,7 @@ describe('Blockchain', () => {
     });
     const lastBlock = node1.bc.lastBlock();
     node1.addNewBlock(Block.create(
-        lastBlock.hash, [], [tx], lastBlock.number + 1, lastBlock.epoch + 1, '',
+        lastBlock.hash, [], {}, [tx], lastBlock.number + 1, lastBlock.epoch + 1, '',
         node1.account.address, {}, 0, 0));
     assert.deepEqual(
         node1.bc.chain[node1.bc.chain.length -1].transactions[0],
@@ -66,7 +66,7 @@ describe('Blockchain', () => {
     });
     const lastBlock = node1.bc.lastBlock();
     node1.addNewBlock(Block.create(
-        lastBlock.hash, [], [tx], lastBlock.number + 1, lastBlock.epoch + 1, '',
+        lastBlock.hash, [], {}, [tx], lastBlock.number + 1, lastBlock.epoch + 1, '',
         node1.account.address, {}, 0, 0));
     node1.bc.chain[node1.bc.chain.length - 1].transactions = ':(';
     expect(Blockchain.validateChainSegment(node1.bc.chain)).to.equal(false);
@@ -91,7 +91,7 @@ describe('Blockchain', () => {
         const lastBlock = node1.bc.lastBlock();
         const finalRoot = node1.stateManager.getFinalRoot();
         const block = Block.create(
-            lastBlock.hash, [], node1.tp.getValidTransactions(), lastBlock.number + 1, i,
+            lastBlock.hash, [], {}, node1.tp.getValidTransactions(), lastBlock.number + 1, i,
             finalRoot.getProofHash(), node1.account.address, [], 0, 0);
         if (block.number === 500) {
           blockHash = block.hash;
diff --git a/unittest/common-util.test.js b/unittest/common-util.test.js
index 7f8e22a7b..874514b0b 100644
--- a/unittest/common-util.test.js
+++ b/unittest/common-util.test.js
@@ -60,6 +60,31 @@ describe("CommonUtil", () => {
     })
   })
 
+  describe("toHexString", () => {
+    it("when non-string input", () => {
+      expect(CommonUtil.toHexString(0)).to.equal('0x');
+      expect(CommonUtil.toHexString(10)).to.equal('0x');
+      expect(CommonUtil.toHexString(-1)).to.equal('0x');
+      expect(CommonUtil.toHexString(15.5)).to.equal('0x');
+      expect(CommonUtil.toHexString(null)).to.equal('0x');
+      expect(CommonUtil.toHexString(undefined)).to.equal('0x');
+      expect(CommonUtil.toHexString(Infinity)).to.equal('0x');
+      expect(CommonUtil.toHexString(NaN)).to.equal('0x');
+      expect(CommonUtil.toHexString({})).to.equal('0x');
+      expect(CommonUtil.toHexString({a: 'A'})).to.equal('0x');
+      expect(CommonUtil.toHexString([])).to.equal('0x');
+      expect(CommonUtil.toHexString([10])).to.equal('0x');
+      expect(CommonUtil.toHexString(false)).to.equal('0x');
+    })
+
+    it("when string input", () => {
+      expect(CommonUtil.toHexString('')).to.equal('0x');
+      expect(CommonUtil.toHexString('0x0123456789abcdef')).to.equal('0x0123456789abcdef');
+      expect(CommonUtil.toHexString('0x0123456789ABCDEF')).to.equal('0x0123456789abcdef');
+      expect(CommonUtil.toHexString('aAzZ')).to.equal('0x61417a5a');
+    })
+  })
+
   describe("parseJsonOrNull", () => {
     it("when abnormal input", () => {
       assert.deepEqual(CommonUtil.parseJsonOrNull(''), null);
@@ -421,7 +446,7 @@ describe("CommonUtil", () => {
                           }
                         }
                       },
-                      "code": "SUCCESS",
+                      "code": 0,
                       "bandwidth_gas_amount": 0,
                     }
                   },
@@ -430,7 +455,7 @@ describe("CommonUtil", () => {
                 }
               }
             },
-            "code": "SUCCESS",
+            "code": 0,
             "bandwidth_gas_amount": 0,
           }
         },
@@ -456,7 +481,7 @@ describe("CommonUtil", () => {
                           }
                         }
                       },
-                      "code": "SUCCESS",
+                      "code": 0,
                       "bandwidth_gas_amount": 0,
                     }
                   },
@@ -465,7 +490,7 @@ describe("CommonUtil", () => {
                 }
               }
             },
-            "code": "SUCCESS",
+            "code": 0,
             "bandwidth_gas_amount": 0,
           }
         },
@@ -493,7 +518,7 @@ describe("CommonUtil", () => {
                           }
                         }
                       },
-                      "code": "SUCCESS",
+                      "code": 0,
                       "bandwidth_gas_amount": 0,
                     }
                   },
@@ -502,7 +527,7 @@ describe("CommonUtil", () => {
                 }
               }
             },
-            "code": "SUCCESS",
+            "code": 0,
             "bandwidth_gas_amount": 0,
           }
         },
@@ -528,7 +553,7 @@ describe("CommonUtil", () => {
                           }
                         }
                       },
-                      "code": "FAILURE",  // A function failed.
+                      "code": 1,  // A function failed.
                       "bandwidth_gas_amount": 0,
                     }
                   },
@@ -537,7 +562,7 @@ describe("CommonUtil", () => {
                 }
               }
             },
-            "code": "SUCCESS",
+            "code": 0,
             "bandwidth_gas_amount": 0,
           }
         },
@@ -551,7 +576,7 @@ describe("CommonUtil", () => {
         "code": 0,
         "func_results": {
           "0x11111": {
-            "code": "SUCCESS",
+            "code": 0,
             "bandwidth_gas_amount": 10,
           }
         },
@@ -627,7 +652,7 @@ describe("CommonUtil", () => {
                               }
                             }
                           },
-                          "code": "SUCCESS",
+                          "code": 0,
                           "bandwidth_gas_amount": 0,
                         }
                       },
@@ -636,7 +661,7 @@ describe("CommonUtil", () => {
                     }
                   }
                 },
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 0,
               }
             },
@@ -674,7 +699,7 @@ describe("CommonUtil", () => {
                               }
                             }
                           },
-                          "code": "SUCCESS",
+                          "code": 0,
                           "bandwidth_gas_amount": 0,
                         }
                       },
@@ -683,7 +708,7 @@ describe("CommonUtil", () => {
                     }
                   }
                 },
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 0,
               }
             },
@@ -723,7 +748,7 @@ describe("CommonUtil", () => {
                               }
                             }
                           },
-                          "code": "SUCCESS",
+                          "code": 0,
                           "bandwidth_gas_amount": 0,
                         }
                       },
@@ -732,7 +757,7 @@ describe("CommonUtil", () => {
                     }
                   }
                 },
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 0,
               }
             },
@@ -779,7 +804,7 @@ describe("CommonUtil", () => {
                     }
                   }
                 },
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 0,
               }
             },
@@ -811,7 +836,7 @@ describe("CommonUtil", () => {
             "code": 0,
             "func_results": {
               "0x11111": {
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 10,
               }
             },
@@ -873,7 +898,7 @@ describe("CommonUtil", () => {
                           }
                         }
                       },
-                      "code": "SUCCESS",
+                      "code": 0,
                       "bandwidth_gas_amount": 10
                     }
                   },
@@ -882,7 +907,7 @@ describe("CommonUtil", () => {
                 }
               }
             },
-            "code": "SUCCESS",
+            "code": 0,
             "bandwidth_gas_amount": 20,
           }
         },
@@ -913,7 +938,7 @@ describe("CommonUtil", () => {
                           }
                         }
                       },
-                      "code": "SUCCESS",
+                      "code": 0,
                       "bandwidth_gas_amount": 10
                     }
                   },
@@ -922,7 +947,7 @@ describe("CommonUtil", () => {
                 }
               }
             },
-            "code": "SUCCESS",
+            "code": 0,
             "bandwidth_gas_amount": 20,
           }
         },
@@ -956,7 +981,7 @@ describe("CommonUtil", () => {
                           }
                         }
                       },
-                      "code": "SUCCESS",
+                      "code": 0,
                       "bandwidth_gas_amount": 10
                     }
                   },
@@ -965,7 +990,7 @@ describe("CommonUtil", () => {
                 }
               }
             },
-            "code": "SUCCESS",
+            "code": 0,
             "bandwidth_gas_amount": 20,
           }
         },
@@ -1002,7 +1027,7 @@ describe("CommonUtil", () => {
                               }
                             }
                           },
-                          "code": "SUCCESS",
+                          "code": 0,
                           "bandwidth_gas_amount": 10
                         }
                       },
@@ -1011,7 +1036,7 @@ describe("CommonUtil", () => {
                     }
                   }
                 },
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 20
               }
             },
@@ -1051,7 +1076,7 @@ describe("CommonUtil", () => {
                               }
                             }
                           },
-                          "code": "SUCCESS",
+                          "code": 0,
                           "bandwidth_gas_amount": 10
                         }
                       },
@@ -1060,7 +1085,7 @@ describe("CommonUtil", () => {
                     }
                   }
                 },
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 20
               }
             },
@@ -1103,7 +1128,7 @@ describe("CommonUtil", () => {
                               }
                             }
                           },
-                          "code": "SUCCESS",
+                          "code": 0,
                           "bandwidth_gas_amount": 10
                         }
                       },
@@ -1112,7 +1137,7 @@ describe("CommonUtil", () => {
                     }
                   }
                 },
-                "code": "SUCCESS",
+                "code": 0,
                 "bandwidth_gas_amount": 20
               }
             },
diff --git a/unittest/consensus.test.js b/unittest/consensus.test.js
index 91566b203..b21b48c2b 100644
--- a/unittest/consensus.test.js
+++ b/unittest/consensus.test.js
@@ -42,8 +42,8 @@ describe("Consensus", () => {
     const voteTx = getTransaction(node2, {
         operation: { 
           type: 'SET_VALUE', 
-          ref: `/consensus/number/1/vote/${node2.account.address}`,
-          value: { block_hash: lastBlock.hash, stake: 100000 }
+          ref: `/consensus/number/1/${lastBlock.hash}/vote/${node2.account.address}`,
+          value: { block_hash: lastBlock.hash, stake: 100000, is_against: false }
         },
         nonce: -1,
         gas_price: 1
@@ -69,8 +69,8 @@ describe("Consensus", () => {
     const voteTx = getTransaction(node2, {
         operation: {
           type: 'SET_VALUE', 
-          ref: `/consensus/number/${lastBlock.number}/vote/${addr}`,
-          value: { block_hash: lastBlock.hash, stake: 100000 }
+          ref: `/consensus/number/${lastBlock.number}/${lastBlock.hash}/vote/${addr}`,
+          value: { block_hash: lastBlock.hash, stake: 100000, is_against: false }
         },
         nonce: -1,
         gas_price: 1
@@ -116,7 +116,7 @@ describe("Consensus", () => {
     // Bypass whitelist rule check (need owner's private key)
     const tempDb = node1.createTempDb(node1.db.stateVersion, 'CONSENSUS_UNIT_TEST', lastBlock.number);
     tempDb.writeDatabase(
-        [PredefinedDbPaths.VALUES_ROOT, PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.WHITELIST, addr],
+        [PredefinedDbPaths.VALUES_ROOT, PredefinedDbPaths.CONSENSUS, PredefinedDbPaths.CONSENSUS_WHITELIST, addr],
         true);
     node1.cloneAndFinalizeVersion(tempDb.stateVersion, -1); // Bypass already existing final state version
     
diff --git a/unittest/db.test.js b/unittest/db.test.js
index fce55e399..a9c6a5b6e 100644
--- a/unittest/db.test.js
+++ b/unittest/db.test.js
@@ -12,7 +12,6 @@ const {
   GenesisFunctions,
   GenesisRules,
   GenesisOwners,
-  ProofProperties,
   PredefinedDbPaths,
   StateInfoProperties,
   SERVICE_STATE_BUDGET,
@@ -414,55 +413,55 @@ describe("DB operations", () => {
 
       it('when retrieving value with include_proof', () => {
         assert.deepEqual(node.db.getValue('/apps/test', { includeProof: true }), {
-          ".proof_hash": "0x753458b0796af84a76e4256ec295c65a7563f5ef2c855f2ecc3e15f47887b8bf",
+          ".proof_hash": "0xf1f51cb458ef3881fefbecf91db5450e601d462099e43776863f2cbb78642286",
           "ai": {
-            ".proof_hash": "0x475a10041bd4a36132a63b16f5ba0a2b528642f01a8d00923969507289239c44",
+            ".proof_hash": "0xc49ca014a4d5328cfdb74164bcb8c00578719335194b07a8b91af1db0048f0bb",
             ".proof_hash:baz": "0x74e6d7e9818333ef5d6f4eb74dc0ee64537c9e142e4fe55e583476a62b539edf",
             ".proof_hash:comcom": "0x90840252cdaacaf90d95c14f9d366f633fd53abf7a2c359f7abfb7f651b532b5",
             ".proof_hash:foo": "0xea86f62ccb8ed9240afb6c9090be001ef7859bf40e0782f2b8d3579b3d8310a4",
             "baz": "qux",
             "comcom": 123,
-            "foo": "bar",
+            "foo": "bar"
           },
           "decrement": {
-            ".proof_hash": "0x875a06d5687f3fe01ddee9a76b48c5439a233ad4753980d239e7b91793f4b2a3",
+            ".proof_hash": "0x11d1aa4946a3e44e3d467d4da85617d56aecd2559fdd6d9e5dd8fb6b5ded71b8",
             ".proof_hash:value": "0xc3c28ad8a683cb7f3d8cf05420651e08e14564e18a1805fe33720cd9d7d2deb2",
-            "value": 20,
+            "value": 20
           },
           "increment": {
-            ".proof_hash": "0x875a06d5687f3fe01ddee9a76b48c5439a233ad4753980d239e7b91793f4b2a3",
+            ".proof_hash": "0x11d1aa4946a3e44e3d467d4da85617d56aecd2559fdd6d9e5dd8fb6b5ded71b8",
             ".proof_hash:value": "0xc3c28ad8a683cb7f3d8cf05420651e08e14564e18a1805fe33720cd9d7d2deb2",
-            "value": 20,
+            "value": 20
           },
           "nested": {
-            ".proof_hash": "0xb2d436a46347f073c9fbbc6daf074c6020493d39bbcf6219f483d80ba4fcba12",
+            ".proof_hash": "0x8763e301c728729e38c1f5500a2af7163783bdf0948a7baf7bc87b35f33b347f",
             "far": {
-              ".proof_hash": "0xdb10e1d3b0aa83908d4414d79940160b4ee59fab7363c3223685829b31c9912d",
+              ".proof_hash": "0xc8b9114b37d8ece398eb8dde73b00bf5037f6b11d97eff11b5212b5f30f32417",
               ".proof_hash:down": "0x4611868537ffbffa17f70f8ddb7cf5aacc6b4d1b32817315f631a2c7d6b6481d",
-              "down": 456,
-            },
+              "down": 456
+            }
           },
           "shards": {
-            ".proof_hash": "0xca7a8628678dd40de218e17a9df8acbbf31e596397ffcf94af36c2134be31e16",
+            ".proof_hash": "0x8ab46f23c6dddce173709cbc935a33d816825ffebabc4f23d02c3d2aea85fba3",
             "disabled_shard": {
-              ".proof_hash": "0xd05c3b7418eedc09e24d61376ddffabc28245006150e8ade7ee586109821c3f9",
+              ".proof_hash": "0xc0d5ac161046ecbf67ae597b3e1d96e53e78d71c0193234f78f2514dbf952161",
               ".proof_hash:path": "0xd024945cba75febe35837d24c977a187a6339888d99d505c1be63251fec52279",
               ".shard": {
-                ".proof_hash": "0xc1def4354bd8f269460896e38f288dba21d77d2c115a02285f6cce8f7e646fca",
+                ".proof_hash": "0x1908ddba2acbc0181cdc29b035c7ce371d3ed38f39b39cad3eb7e0704ccaa57b",
                 ".proof_hash:sharding_enabled": "0x055600b34c3a8a69ea5dfc2cd2f92336933be237c8b265089f3114b38b4a540a",
-                "sharding_enabled": false,
+                "sharding_enabled": false
               },
-              "path": 10,
+              "path": 10
             },
             "enabled_shard": {
-              ".proof_hash": "0xb9ab65702643eccef3d025b650a02af574b22fa52be1ac9272f20b382e21e84d",
+              ".proof_hash": "0x4b754c4a1a1f99d1ad9bc4a1edbeb7e2ceec6828313b52f8b880ee1cded3e4d3",
               ".proof_hash:path": "0xd024945cba75febe35837d24c977a187a6339888d99d505c1be63251fec52279",
               ".shard": {
-                ".proof_hash": "0xca256dadfca4c89edbc3de62b0732eac55d792b4661fdbb1c1455bfc1ef9048b",
+                ".proof_hash": "0xc308394fc297eb293cbef148c58665e9208a96e3664e86695db9d29c273dae96",
                 ".proof_hash:sharding_enabled": "0x1eafc1e61d5b7b28f90a34330bf62265eeb466e012aa7318098003f37e4c61cc",
-                "sharding_enabled": true,
+                "sharding_enabled": true
               },
-              "path": 10,
+              "path": 10
             }
           }
         })
@@ -1968,7 +1967,7 @@ describe("DB operations", () => {
                             }
                           }
                         },
-                        "code": "SUCCESS",
+                        "code": 0,
                         "bandwidth_gas_amount": 0,
                       }
                     },
@@ -1977,7 +1976,7 @@ describe("DB operations", () => {
                   }
                 }
               },
-              "code": "SUCCESS",
+              "code": 0,
               "bandwidth_gas_amount": 0
             }
           },
@@ -2073,7 +2072,7 @@ describe("DB operations", () => {
                             }
                           }
                         },
-                        "code": "FAILURE",
+                        "code": 1,
                         "bandwidth_gas_amount": 0,
                       }
                     },
@@ -2082,7 +2081,7 @@ describe("DB operations", () => {
                   }
                 }
               },
-              "code": "FAILURE",
+              "code": 1,
               "bandwidth_gas_amount": 0,
             }
           },
@@ -2383,7 +2382,7 @@ describe("DB operations", () => {
                                 }
                               }
                             },
-                            "code": "SUCCESS",
+                            "code": 0,
                             "bandwidth_gas_amount": 0
                           }
                         },
@@ -2392,7 +2391,7 @@ describe("DB operations", () => {
                       }
                     }
                   },
-                  "code": "SUCCESS",
+                  "code": 0,
                   "bandwidth_gas_amount": 0
                 }
               },
@@ -2507,7 +2506,7 @@ describe("DB operations", () => {
                                 }
                               }
                             },
-                            "code": "FAILURE",
+                            "code": 1,
                             "bandwidth_gas_amount": 0,
                           }
                         },
@@ -2516,7 +2515,7 @@ describe("DB operations", () => {
                       }
                     }
                   },
-                  "code": "FAILURE",
+                  "code": 1,
                   "bandwidth_gas_amount": 0,
                 }
               },
@@ -2604,7 +2603,7 @@ describe("DB operations", () => {
         const maxHeightTxBody = {
           operation: {
             type: 'SET_VALUE',
-            ref: '/apps/test/4/5/6/7/8/9/10/11/12/13/14/15/16/17/18/19/20',
+            ref: '/apps/test/4/5/6/7/8/9/10/11/12/13/14/15/16/17/18/19/20/21/22/23/24/25/26/27/28/29/30',
             value: 'some value',
           },
           gas_price: 0,
@@ -2625,7 +2624,7 @@ describe("DB operations", () => {
             },
             state: {
               app: {
-                test: 2956
+                test: 4596
               },
               service: 8
             }
@@ -2636,7 +2635,7 @@ describe("DB operations", () => {
         const overHeightTxBody = {
           operation: {
             type: 'SET_VALUE',
-            ref: '/apps/test/4/5/6/7/8/9/10/11/12/13/14/15/16/17/18/19/20/21',
+            ref: '/apps/test/4/5/6/7/8/9/10/11/12/13/14/15/16/17/18/19/20/21/22/23/24/25/26/27/28/29/30/31',
             value: 'some value',
           },
           gas_price: 0,
@@ -2646,7 +2645,7 @@ describe("DB operations", () => {
         const overHeightTx = Transaction.fromTxBody(overHeightTxBody, node.account.private_key);
         assert.deepEqual(node.db.executeTransaction(overHeightTx, false, true, node.bc.lastBlockNumber() + 1), {
           code: 23,
-          error_message: "Out of tree height limit (21 > 20)",
+          error_message: "Out of tree height limit (31 > 30)",
           gas_amount_charged: 0,
           bandwidth_gas_amount: 1,
           gas_cost_total: 0,
@@ -2674,7 +2673,7 @@ describe("DB operations", () => {
             result: {
               timestamp: 1568798344000,
               tx_hash: "0xb23fbdfb7b38dc4859872c565b1b0e4140ca4b7896397c817a290b2507e79708",
-              code: "SUCCESS"
+              code: 0
             }
           }
         }
@@ -2694,7 +2693,7 @@ describe("DB operations", () => {
             app: {},
           },
           state: {
-            service: 3550560
+            service: 3541560
           } 
         };
         const overSizeTxBody = {
@@ -2717,16 +2716,16 @@ describe("DB operations", () => {
         const overSizeTx = Transaction.fromTxBody(overSizeTxBody, node.account.private_key);
         const res = node.db.executeTransaction(overSizeTx, false, true, node.bc.lastBlockNumber() + 1);
         assert.deepEqual(res.code, 25);
-        assert.deepEqual(res.error_message, "Exceeded state budget limit for services (10791482 > 10000000)");
+        assert.deepEqual(res.error_message, "Exceeded state budget limit for services (10757870 > 10000000)");
         assert.deepEqual(res.gas_amount_total, expectedGasAmountTotal);
-        assert.deepEqual(res.gas_cost_total, 3.5550599999999997);
+        assert.deepEqual(res.gas_cost_total, 3.5460599999999998);
       });
 
       it("cannot exceed apps state budget", () => {
         const overSizeTree = {};
         for (let i = 0; i < 1000; i++) {
           overSizeTree[i] = {};
-          for (let j = 0; j < 100; j++) {
+          for (let j = 0; j < 75; j++) {
             overSizeTree[i][j] = 'a';
           }
         }
@@ -2743,10 +2742,10 @@ describe("DB operations", () => {
         const overSizeTx = Transaction.fromTxBody(overSizeTxBody, node.account.private_key);
         const res = node.db.executeTransaction(overSizeTx, false, true, node.bc.lastBlockNumber() + 1);
         assert.deepEqual(res.code, 26);
-        assert.deepEqual(res.error_message, "Exceeded state budget limit for apps (16769332 > 9000000)");
+        assert.deepEqual(res.error_message, "Exceeded state budget limit for apps (12621228 > 9000000)");
         assert.deepEqual(res.gas_amount_total, {
           bandwidth: { service: 0, app: { test: 1 } },
-          state: { service: 8, app: { test: 16746108 } }
+          state: { service: 8, app: { test: 12596108 } }
         });
         assert.deepEqual(res.gas_cost_total, 0);
       });
@@ -2862,7 +2861,6 @@ describe("DB operations", () => {
         "terminal_1c": "",
         "node_1a": {
           "node_2": {
-            "terminal_3": null,
             "node_3": "a value"
           }
         },
@@ -2954,7 +2952,6 @@ describe("DB operations", () => {
         "terminal_1c": "",
         "node_1a": {
           "node_2": {
-            "terminal_3": null,
             "node_3": "another value"
           }
         },
@@ -2968,6 +2965,8 @@ describe("DB operations", () => {
       expect(node.db.setValue(
           "/apps/test/empty_values/node_0/node_1a/node_2/node_3", null).code).to.equal(0);
       assert.deepEqual(node.db.getValue("/apps/test/empty_values/node_0"), {
+        "terminal_1a": null,
+        "terminal_1b": null,
         "terminal_1c": "",
         "node_1b": {
           "terminal_2": null,
@@ -3723,7 +3722,7 @@ describe("DB sharding config", () => {
     it("setValue with isGlobal = true", () => {
       expect(node.db.setValue(
           "/apps/afan/apps/test/test_sharding/some/path/to/value", newValue, { addr: '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1' },
-          null, { extra: { executed_at: 1234567890000 }}, { isGlobal: true }).code)
+          null, { extra: { executed_at: 1234567890000 }}, 1234567890000, { isGlobal: true }).code)
               .to.equal(0);
       expect(node.db.getValue("/apps/test/test_sharding/some/path/to/value")).to.equal(newValue);
     })
@@ -3731,7 +3730,7 @@ describe("DB sharding config", () => {
     it("setValue with isGlobal = true and non-existing path", () => {
       expect(node.db.setValue(
           "/apps/some/non-existing/path", newValue, { addr: '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1' },
-          null, { extra: { executed_at: 1234567890000 }}, { isGlobal: true }).code)
+          null, { extra: { executed_at: 1234567890000 }}, 1234567890000, { isGlobal: true }).code)
               .to.equal(0);
     })
 
@@ -3746,7 +3745,7 @@ describe("DB sharding config", () => {
     it("setValue with isGlobal = true and non-writable path with sharding", () => {
       expect(node.db.setValue(
           "/apps/afan/apps/test/test_sharding/shards/enabled_shard/path", 20, '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1', null, null,
-          { isGlobal: true }).code)
+          1234567890000, { isGlobal: true }).code)
               .to.equal(0);
       expect(node.db.getValue("/apps/afan/apps/test/test_sharding/shards/enabled_shard/path", { isShallow: false, isGlobal: true }))
           .to.equal(10);  // value unchanged
@@ -3761,7 +3760,7 @@ describe("DB sharding config", () => {
     it("setValue with isGlobal = true and writable path with sharding", () => {
       expect(node.db.setValue(
           "apps/afan/apps/test/test_sharding/shards/disabled_shard/path", 20, { addr: '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1' },
-          null, { extra: { executed_at: 1234567890000 }}, { isGlobal: true }).code)
+          null, { extra: { executed_at: 1234567890000 }}, 1234567890000, { isGlobal: true }).code)
               .to.equal(0);
       expect(node.db.getValue("apps/afan/apps/test/test_sharding/shards/disabled_shard/path", { isShallow: false, isGlobal: true }))
           .to.equal(20);  // value changed
@@ -3778,14 +3777,14 @@ describe("DB sharding config", () => {
     it("incValue with isGlobal = true", () => {
       expect(node.db.incValue(
           "/apps/afan/apps/test/test_sharding/some/path/to/number", incDelta, { addr: '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1' },
-          null, { extra: { executed_at: 1234567890000 }}, { isGlobal: true }).code)
+          null, { extra: { executed_at: 1234567890000 }}, 1234567890000, { isGlobal: true }).code)
               .to.equal(0);
       expect(node.db.getValue("/apps/test/test_sharding/some/path/to/number")).to.equal(10 + incDelta);
     })
 
     it("incValue with isGlobal = true and non-existing path", () => {
       expect(node.db.incValue(
-          "/apps/some/non-existing/path", incDelta, { addr: '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1' }, null, null, { isGlobal: true }).code)
+          "/apps/some/non-existing/path", incDelta, { addr: '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1' }, null, null, 1234567890000, { isGlobal: true }).code)
               .to.equal(0);
     })
 
@@ -3800,7 +3799,7 @@ describe("DB sharding config", () => {
     it("setValue with isGlobal = true and non-writable path with sharding", () => {
       expect(node.db.incValue(
           "/apps/afan/apps/test/test_sharding/shards/enabled_shard/path", 5, { addr: '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1' },
-          null, null, { isGlobal: true }).code)
+          null, null, 1234567890000, { isGlobal: true }).code)
               .to.equal(0);
       expect(node.db.getValue("apps/afan/apps/test/test_sharding/shards/enabled_shard/path", { isShallow: false, isGlobal: true }))
           .to.equal(10);  // value unchanged
@@ -3815,7 +3814,7 @@ describe("DB sharding config", () => {
     it("setValue with isGlobal = true and writable path with sharding", () => {
       expect(node.db.incValue(
           "/apps/afan/apps/test/test_sharding/shards/disabled_shard/path", 5, { addr: '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1' },
-          null, { extra: { executed_at: 1234567890000 }}, { isGlobal: true }).code)
+          null, { extra: { executed_at: 1234567890000 }}, 1234567890000, { isGlobal: true }).code)
               .to.equal(0);
       expect(node.db.getValue("/apps/afan/apps/test/test_sharding/shards/disabled_shard/path", { isShallow: false, isGlobal: true }))
           .to.equal(15);  // value changed
@@ -3832,14 +3831,14 @@ describe("DB sharding config", () => {
     it("decValue with isGlobal = true", () => {
       expect(node.db.decValue(
           "/apps/afan/apps/test/test_sharding/some/path/to/number", decDelta, { addr: '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1' },
-          null, { extra: { executed_at: 1234567890000 }}, { isGlobal: true }).code)
+          null, { extra: { executed_at: 1234567890000 }}, 1234567890000, { isGlobal: true }).code)
               .to.equal(0);
       expect(node.db.getValue("/apps/test/test_sharding/some/path/to/number")).to.equal(10 - decDelta);
     })
 
     it("decValue with isGlobal = true and non-existing path", () => {
       expect(node.db.decValue(
-          "/apps/some/non-existing/path", decDelta, { addr: '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1' }, null, null, { isGlobal: true }).code)
+          "/apps/some/non-existing/path", decDelta, { addr: '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1' }, null, null, 1234567890000, { isGlobal: true }).code)
               .to.equal(0);
     })
 
@@ -3854,7 +3853,7 @@ describe("DB sharding config", () => {
     it("setValue with isGlobal = true and non-writable path with sharding", () => {
       expect(node.db.decValue(
           "/apps/afan/apps/test/test_sharding/shards/enabled_shard/path", 5, { addr: '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1' },
-          null, null, { isGlobal: true }).code)
+          null, null, 1234567890000, { isGlobal: true }).code)
               .to.equal(0);
       expect(node.db.getValue(
           "/apps/afan/apps/test/test_sharding/shards/enabled_shard/path", { isShallow: false, isGlobal: true }))
@@ -3871,7 +3870,7 @@ describe("DB sharding config", () => {
     it("setValue with isGlobal = true and writable path with sharding", () => {
       expect(node.db.decValue(
           "/apps/afan/apps/test/test_sharding/shards/disabled_shard/path", 5, { addr: '0x09A0d53FDf1c36A131938eb379b98910e55EEfe1' },
-          null, { extra: { executed_at: 1234567890000 }}, { isGlobal: true }).code)
+          null, { extra: { executed_at: 1234567890000 }}, 1234567890000, { isGlobal: true }).code)
               .to.equal(0);
       expect(node.db.getValue("/apps/afan/apps/test/test_sharding/shards/disabled_shard/path", { isShallow: false, isGlobal: true }))
         .to.equal(5);  // value changed
@@ -4455,47 +4454,11 @@ describe("Proof hash", () => {
 
   describe("State proof (getStateProof)", () => {
     it("tests proof with a null case", () => {
-      const rootNode = node.db.stateRoot;
       assert.deepEqual(null, node.db.getStateProof('/apps/test/test'));
     });
 
     it("tests proof with owners, rules, values and functions", () => {
-      const rootNode = node.db.stateRoot;
-      const ownersNode = node.db.getRefForReading(['owners']);
-      const rulesNode = node.db.getRefForReading(['rules']);
-      const valuesNode = node.db.getRefForReading(['values']);
-      const functionNode = node.db.getRefForReading(['functions']);
-      const rootProof = { [ProofProperties.PROOF_HASH]: rootNode.getProofHash() };
-      const secondLevelProof = JSON.parse(JSON.stringify(rootProof));
-      rootNode.getChildLabels().forEach(label => {
-        Object.assign(secondLevelProof,
-          { [label]: { [ProofProperties.PROOF_HASH]: rootNode.getChild(label).getProofHash() } });
-      });
-      const ownersProof = JSON.parse(JSON.stringify(secondLevelProof));
-      ownersNode.getChildLabels().forEach(label => {
-        Object.assign(ownersProof.owners,
-          { [label]: { [ProofProperties.PROOF_HASH]: ownersNode.getChild(label).getProofHash() } });
-      });
-      const rulesProof = JSON.parse(JSON.stringify(secondLevelProof));
-      rulesNode.getChildLabels().forEach(label => {
-        Object.assign(rulesProof.rules,
-          { [label]: { [ProofProperties.PROOF_HASH]: rulesNode.getChild(label).getProofHash() } });
-      });
-      const valuesProof = JSON.parse(JSON.stringify(secondLevelProof));
-      valuesNode.getChildLabels().forEach(label => {
-        Object.assign(valuesProof.values,
-          { [label]: { [ProofProperties.PROOF_HASH]: valuesNode.getChild(label).getProofHash() } });
-      });
-      const functionsProof = JSON.parse(JSON.stringify(secondLevelProof));
-      functionNode.getChildLabels().forEach(label => {
-        Object.assign(functionsProof.functions,
-          { [label]: { [ProofProperties.PROOF_HASH]: functionNode.getChild(label).getProofHash() } });
-      });
-      assert.deepEqual(rootProof, node.db.getStateProof('/'));
-      assert.deepEqual(ownersProof, node.db.getStateProof('/owners/apps'));
-      assert.deepEqual(rulesProof, node.db.getStateProof('/rules/apps'));
-      assert.deepEqual(valuesProof, node.db.getStateProof('/values/apps'));
-      assert.deepEqual(functionsProof, node.db.getStateProof('/functions/apps'));
+      expect(node.db.getStateProof('/')['.proof_hash']).to.not.equal(null);
     });
   });
 });
@@ -4542,11 +4505,11 @@ describe("State info (getStateInfo)", () => {
 
       // Existing paths.
       assert.deepEqual(node.db.getStateInfo('/values/apps/test/label1'), {
-        "proof_hash": "0x213304021f1ea1e8f7954c815d49207c0a42ab4bdf09929263369fa5f4d77c8b",
+        "proof_hash": "0xe4fd1f81f45b74ccd16540efa905abde37b6660d3fe9fb18eb3bf6b3e7cd215a",
         "tree_bytes": 922,
         "tree_height": 2,
         "tree_size": 5,
-        "version": "NODE:0",
+        "version": "NODE:0"
       });
       assert.deepEqual(node.db.getStateInfo('/values/apps/test/label1/label11'), {
         "proof_hash": "0xa8681012b27ff56a45aa80f6f4d95c66c3349046cdd18cdc77028b6a634c9b0b",
@@ -4556,7 +4519,7 @@ describe("State info (getStateInfo)", () => {
         "version": "NODE:0",
       });
       assert.deepEqual(node.db.getStateInfo('/values/apps/test/label1/label12'), {
-        "proof_hash": "0xbc8b6e1e9e369b5af09e14fea3769c348d66e453b3a2fc6dbec0d00278e094e7",
+        "proof_hash": "0x19037329315c0182c0f965a786e6d0659bb374e907a3937f885f0da3984cfa6e",
         "tree_bytes": 560,
         "tree_height": 1,
         "tree_size": 3,
@@ -4577,7 +4540,7 @@ describe("State info (getStateInfo)", () => {
         "version": "NODE:0",
       });
       assert.deepEqual(node.db.getStateInfo('/values/apps/test/label2'), {
-        "proof_hash": "0x7b614d2449c2ce477ac040c52b78798e5ff36a20b83115b6af8688f5e88a813f",
+        "proof_hash": "0x0088bff9a36081510c230f5fd6b6581b81966b185414e625df7553693d6517e3",
         "tree_bytes": 536,
         "tree_height": 1,
         "tree_size": 3,
@@ -4609,11 +4572,11 @@ describe("State info (getStateInfo)", () => {
       assert.deepEqual(result.code, 0);
 
       assert.deepEqual(node.db.getStateInfo('/values/apps/test/label1'), {
-        "proof_hash": "0x1b8f144f5692c88c242776485c0cafc184d4724942578752d083c615d84a1caa",
+        "proof_hash": "0xe037f0083e30127f0e5088be69c2629a7e14e18518ee736fc31d86ec39b3c459",
         "tree_bytes": 348,
         "tree_height": 1,
         "tree_size": 2,
-        "version": "NODE:0",
+        "version": "NODE:0"
       });
       assert.deepEqual(node.db.getStateInfo('/values/apps/test/label1/label11'), {
         "proof_hash": "0xa8681012b27ff56a45aa80f6f4d95c66c3349046cdd18cdc77028b6a634c9b0b",
@@ -4624,7 +4587,7 @@ describe("State info (getStateInfo)", () => {
       });
       assert.deepEqual(node.db.getStateInfo('/values/apps/test/label1/label12'), null);
       assert.deepEqual(node.db.getStateInfo('/values/apps/test/label2'), {
-        "proof_hash": "0x7b614d2449c2ce477ac040c52b78798e5ff36a20b83115b6af8688f5e88a813f",
+        "proof_hash": "0x0088bff9a36081510c230f5fd6b6581b81966b185414e625df7553693d6517e3",
         "tree_bytes": 536,
         "tree_height": 1,
         "tree_size": 3,
@@ -4642,21 +4605,21 @@ describe("State info (getStateInfo)", () => {
       assert.deepEqual(result.code, 0);
 
       assert.deepEqual(node.db.getStateInfo('/values/apps/test/label1'), {
-        "proof_hash": "0x052b9dbac10fca45626652f264b9896216da0ce6f1b55d10934b7e9cb9141871",
+        "proof_hash": "0xc751739c3275e0b4c143835fcc0342b80af43a74cf338a8571c17e727643bbe7",
         "tree_bytes": 906,
         "tree_height": 2,
         "tree_size": 5,
-        "version": "NODE:0",
+        "version": "NODE:0"
       });
       assert.deepEqual(node.db.getStateInfo('/values/apps/test/label2'), {
-        "proof_hash": "0x7da207e739139a3fabbcb53c9a2b91f786441b903ffd1de445e69d921f9f30af",
+        "proof_hash": "0xdd1c06ba6d6ff93fea2f2a1a3a026692858cd3528424b2f86197e1761539b0e4",
         "tree_bytes": 906,
         "tree_height": 2,
         "tree_size": 5,
         "version": "NODE:0",
       });
       assert.deepEqual(node.db.getStateInfo('/values/apps/test/label2/label21'), {
-        "proof_hash": "0x805586e32d13b938808c5e283c027d0fa7f8b496bdb6fdc8cd5a57d0b12c72af",
+        "proof_hash": "0xdfe61d4a6c026b34261bc83f4c9d5d24deaed1671177fee24a889930588edd89",
         "tree_bytes": 544,
         "tree_height": 1,
         "tree_size": 3,
diff --git a/unittest/functions.test.js b/unittest/functions.test.js
index 77d778fb3..07ab5c4b2 100644
--- a/unittest/functions.test.js
+++ b/unittest/functions.test.js
@@ -146,7 +146,7 @@ describe("Functions", () => {
             null, null, null, transaction);
         assert.deepEqual(func_results, {
           "0x11111": {
-            "code": "SUCCESS",
+            "code": 0,
             "bandwidth_gas_amount": 10,
           }
         });
@@ -422,7 +422,7 @@ describe("Functions", () => {
                 }
               }
             },
-            "code": "SUCCESS",
+            "code": 0,
             "bandwidth_gas_amount": 1000
           }
         });
@@ -477,7 +477,7 @@ describe("Functions", () => {
                 }
               }
             },
-            "code": "SUCCESS",
+            "code": 0,
             "bandwidth_gas_amount": 0
           }
         });
@@ -512,7 +512,7 @@ describe("Functions", () => {
             null, null, null, transaction);
         assert.deepEqual(func_results, {
           "0x11111": {
-            "code": "SUCCESS",
+            "code": 0,
             "bandwidth_gas_amount": 10,
           }
         });
diff --git a/unittest/p2p-util.test.js b/unittest/p2p-util.test.js
index 6a99a621d..d88bed57a 100644
--- a/unittest/p2p-util.test.js
+++ b/unittest/p2p-util.test.js
@@ -5,7 +5,8 @@ const expect = chai.expect;
 const assert = chai.assert;
 const {
   CURRENT_PROTOCOL_VERSION,
-  DATA_PROTOCOL_VERSION
+  DATA_PROTOCOL_VERSION,
+  NETWORK_ID
 } = require('../common/constants');
 
 describe("P2P Util", () => {
@@ -107,6 +108,7 @@ describe("P2P Util", () => {
         data: mockDataObj,
         protoVer: CURRENT_PROTOCOL_VERSION,
         dataProtoVer: DATA_PROTOCOL_VERSION,
+        networkId: NETWORK_ID,
         timestamp: encapsulatedMessage.timestamp
       });
     });
diff --git a/unittest/radix-child-map.test.js b/unittest/radix-child-map.test.js
new file mode 100644
index 000000000..37b1f6d27
--- /dev/null
+++ b/unittest/radix-child-map.test.js
@@ -0,0 +1,191 @@
+const RadixChildMap = require('../db/radix-child-map');
+const chai = require('chai');
+const expect = chai.expect;
+const assert = chai.assert;
+
+describe("radix-child-map", () => {
+  describe("Static utils", () => {
+    it("_labelRadixToIndex", () => {
+      // valid input
+      expect(RadixChildMap._labelRadixToIndex('0')).to.equal(0);
+      expect(RadixChildMap._labelRadixToIndex('1')).to.equal(1);
+      expect(RadixChildMap._labelRadixToIndex('2')).to.equal(2);
+      expect(RadixChildMap._labelRadixToIndex('3')).to.equal(3);
+      expect(RadixChildMap._labelRadixToIndex('4')).to.equal(4);
+      expect(RadixChildMap._labelRadixToIndex('5')).to.equal(5);
+      expect(RadixChildMap._labelRadixToIndex('6')).to.equal(6);
+      expect(RadixChildMap._labelRadixToIndex('7')).to.equal(7);
+      expect(RadixChildMap._labelRadixToIndex('8')).to.equal(8);
+      expect(RadixChildMap._labelRadixToIndex('9')).to.equal(9);
+      expect(RadixChildMap._labelRadixToIndex('a')).to.equal(10);
+      expect(RadixChildMap._labelRadixToIndex('b')).to.equal(11);
+      expect(RadixChildMap._labelRadixToIndex('c')).to.equal(12);
+      expect(RadixChildMap._labelRadixToIndex('d')).to.equal(13);
+      expect(RadixChildMap._labelRadixToIndex('e')).to.equal(14);
+      expect(RadixChildMap._labelRadixToIndex('f')).to.equal(15);
+
+      // invalid input
+      expect(RadixChildMap._labelRadixToIndex('')).to.equal(-1);
+      expect(RadixChildMap._labelRadixToIndex(' ')).to.equal(-1);
+      expect(RadixChildMap._labelRadixToIndex('A')).to.equal(-1);
+      expect(RadixChildMap._labelRadixToIndex('B')).to.equal(-1);
+      expect(RadixChildMap._labelRadixToIndex('C')).to.equal(-1);
+      expect(RadixChildMap._labelRadixToIndex('D')).to.equal(-1);
+      expect(RadixChildMap._labelRadixToIndex('E')).to.equal(-1);
+      expect(RadixChildMap._labelRadixToIndex('F')).to.equal(-1);
+    });
+
+    it("_indexToLabelRadix", () => {
+      // valid input
+      expect(RadixChildMap._indexToLabelRadix(0)).to.equal('0');
+      expect(RadixChildMap._indexToLabelRadix(1)).to.equal('1');
+      expect(RadixChildMap._indexToLabelRadix(2)).to.equal('2');
+      expect(RadixChildMap._indexToLabelRadix(3)).to.equal('3');
+      expect(RadixChildMap._indexToLabelRadix(4)).to.equal('4');
+      expect(RadixChildMap._indexToLabelRadix(5)).to.equal('5');
+      expect(RadixChildMap._indexToLabelRadix(6)).to.equal('6');
+      expect(RadixChildMap._indexToLabelRadix(7)).to.equal('7');
+      expect(RadixChildMap._indexToLabelRadix(8)).to.equal('8');
+      expect(RadixChildMap._indexToLabelRadix(9)).to.equal('9');
+      expect(RadixChildMap._indexToLabelRadix(10)).to.equal('a');
+      expect(RadixChildMap._indexToLabelRadix(11)).to.equal('b');
+      expect(RadixChildMap._indexToLabelRadix(12)).to.equal('c');
+      expect(RadixChildMap._indexToLabelRadix(13)).to.equal('d');
+      expect(RadixChildMap._indexToLabelRadix(14)).to.equal('e');
+      expect(RadixChildMap._indexToLabelRadix(15)).to.equal('f');
+
+      // invalid input
+      expect(RadixChildMap._indexToLabelRadix(-1)).to.equal('');
+      expect(RadixChildMap._indexToLabelRadix(16)).to.equal('');
+      expect(RadixChildMap._indexToLabelRadix(17)).to.equal('');
+      expect(RadixChildMap._indexToLabelRadix(100)).to.equal('');
+      expect(RadixChildMap._indexToLabelRadix(0.1)).to.equal('');
+      expect(RadixChildMap._indexToLabelRadix(Infinity)).to.equal('');
+    });
+  });
+
+  describe("APIs", () => {
+    let map;
+
+    beforeEach(() => {
+      map = new RadixChildMap();
+    })
+
+    describe("Initialization", () => {
+      it("constructor", () => {
+        expect(map.size).to.equal(0);
+        expect(map.childArray.length).to.equal(16);
+        map.childArray.forEach((elem) => {
+          expect(elem).to.equal(null);
+        })
+      });
+    });
+
+    describe("get / set / has / delete / keys / values / size", () => {
+      it("simple operations with valid label radix", () => {
+        const labelRadix1 = '0';
+        const labelRadix2 = '1';
+        const child1 = { value: 'child1' };
+        const child2 = { value: 'child2' };
+
+        expect(map.has(labelRadix1)).to.equal(false);
+        expect(map.get(labelRadix1)).to.equal(null);
+        expect(map.has(labelRadix2)).to.equal(false);
+        expect(map.get(labelRadix2)).to.equal(null);
+        expect(map.size).to.equal(0);
+        assert.deepEqual(map.keys(), []);
+        assert.deepEqual(map.values(), []);
+
+        expect(map.set(labelRadix1, child1)).to.equal(true);
+        expect(map.has(labelRadix1)).to.equal(true);
+        expect(map.get(labelRadix1)).to.equal(child1);
+        expect(map.has(labelRadix2)).to.equal(false);
+        expect(map.get(labelRadix2)).to.equal(null);
+        expect(map.size).to.equal(1);
+        assert.deepEqual(map.keys(), [labelRadix1]);
+        assert.deepEqual(map.values(), [child1]);
+
+        expect(map.set(labelRadix2, child2)).to.equal(true);
+        expect(map.has(labelRadix1)).to.equal(true);
+        expect(map.get(labelRadix1)).to.equal(child1);
+        expect(map.has(labelRadix2)).to.equal(true);
+        expect(map.get(labelRadix2)).to.equal(child2);
+        expect(map.size).to.equal(2);
+        assert.deepEqual(map.keys(), [labelRadix1, labelRadix2]);
+        assert.deepEqual(map.values(), [child1, child2]);
+
+        expect(map.delete(labelRadix1)).to.equal(true);
+        expect(map.has(labelRadix1)).to.equal(false);
+        expect(map.get(labelRadix1)).to.equal(null);
+        expect(map.has(labelRadix2)).to.equal(true);
+        expect(map.get(labelRadix2)).to.equal(child2);
+        expect(map.size).to.equal(1);
+        assert.deepEqual(map.keys(), [labelRadix2]);
+        assert.deepEqual(map.values(), [child2]);
+
+        expect(map.delete(labelRadix2)).to.equal(true);
+        expect(map.has(labelRadix1)).to.equal(false);
+        expect(map.get(labelRadix1)).to.equal(null);
+        expect(map.has(labelRadix2)).to.equal(false);
+        expect(map.get(labelRadix2)).to.equal(null);
+        expect(map.size).to.equal(0);
+        assert.deepEqual(map.keys(), []);
+        assert.deepEqual(map.values(), []);
+      });
+
+      it("simple operations with invalid label radix", () => {
+        const child1 = { value: 'child1' };
+
+        expect(map.has(undefined)).to.equal(false);
+        expect(map.has(null)).to.equal(false);
+        expect(map.has(false)).to.equal(false);
+        expect(map.has(0)).to.equal(false);
+        expect(map.has('A')).to.equal(false);
+
+        expect(map.get(undefined)).to.equal(undefined);
+        expect(map.get(null)).to.equal(undefined);
+        expect(map.get(false)).to.equal(undefined);
+        expect(map.get(0)).to.equal(undefined);
+        expect(map.get('A')).to.equal(undefined);
+
+        expect(map.set(undefined, child1)).to.equal(false);
+        expect(map.set(null, child1)).to.equal(false);
+        expect(map.set(false, child1)).to.equal(false);
+        expect(map.set(0, child1)).to.equal(false);
+        expect(map.set('A', child1)).to.equal(false);
+
+        expect(map.delete(undefined)).to.equal(false);
+        expect(map.delete(null)).to.equal(false);
+        expect(map.delete(false)).to.equal(false);
+        expect(map.delete(0)).to.equal(false);
+        expect(map.delete('A')).to.equal(false);
+      });
+
+      it("overwrite", () => {
+        const labelRadix = '0';
+        const child1 = { value: 'child1' };
+        const child2 = { value: 'child2' };
+
+        expect(map.has(labelRadix)).to.equal(false);
+        expect(map.get(labelRadix)).to.equal(null);
+        expect(map.size).to.equal(0);
+        assert.deepEqual(map.keys(), []);
+        assert.deepEqual(map.values(), []);
+
+        expect(map.set(labelRadix, child1)).to.equal(true);
+        expect(map.has(labelRadix)).to.equal(true);
+        expect(map.get(labelRadix)).to.equal(child1);
+        expect(map.size).to.equal(1);
+        assert.deepEqual(map.keys(), [labelRadix]);
+        assert.deepEqual(map.values(), [child1]);
+
+        expect(map.set(labelRadix, child2)).to.equal(true);
+        expect(map.has(labelRadix)).to.equal(true);
+        expect(map.get(labelRadix)).to.equal(child2);
+        expect(map.size).to.equal(1);
+        assert.deepEqual(map.keys(), [labelRadix]);
+        assert.deepEqual(map.values(), [child2]);
+      });
+    });
+  });
+});
diff --git a/unittest/radix-node.test.js b/unittest/radix-node.test.js
new file mode 100644
index 000000000..f508683a3
--- /dev/null
+++ b/unittest/radix-node.test.js
@@ -0,0 +1,850 @@
+const RadixNode = require('../db/radix-node');
+const CommonUtil = require('../common/common-util');
+const StateNode = require('../db/state-node');
+const {
+  HASH_DELIMITER,
+} = require('../common/constants');
+const chai = require('chai');
+const expect = chai.expect;
+const assert = chai.assert;
+
+describe("radix-node", () => {
+  let node;
+
+  beforeEach(() => {
+    node = new RadixNode();
+  })
+
+  describe("Initialization", () => {
+    it("constructor", () => {
+      expect(node.stateNode).to.equal(null);
+      expect(node.labelRadix).to.equal('');
+      expect(node.labelSuffix).to.equal('');
+      expect(node.parent).to.equal(null);
+      expect(node.radixChildMap.size).to.equal(0);
+      expect(node.proofHash).to.equal(null);
+    });
+  });
+
+  describe("stateNode", () => {
+    it("get / set / has / reset", () => {
+      const stateNode = new StateNode();
+      expect(node.getStateNode()).to.equal(null);
+      expect(node.hasStateNode()).to.equal(false);
+      expect(node.setStateNode(stateNode)).to.equal(true);
+      expect(node.getStateNode()).to.equal(stateNode);
+      expect(node.hasStateNode()).to.equal(true);
+      node.resetStateNode();
+      expect(node.getStateNode()).to.equal(null);
+      expect(node.hasStateNode()).to.equal(false);
+    });
+
+    it("set with invalid state node", () => {
+      const invalidStateNode = new RadixNode();
+      expect(node.setStateNode(invalidStateNode)).to.equal(false);
+      expect(node.setStateNode('')).to.equal(false);
+      expect(node.setStateNode(true)).to.equal(false);
+      expect(node.setStateNode(null)).to.equal(false);
+      expect(node.setStateNode(undefined)).to.equal(false);
+    });
+  });
+
+  describe("labelRadix", () => {
+    it("get / set / has / reset", () => {
+      const labelRadix = '0';
+      expect(node.getLabelRadix()).to.equal('');
+      node.setLabelRadix(labelRadix);
+      expect(node.getLabelRadix()).to.equal(labelRadix);
+      node.resetLabelRadix();
+      expect(node.getLabelRadix()).to.equal('');
+    });
+  });
+
+  describe("labelSuffix", () => {
+    it("get / set / has / reset", () => {
+      const labelSuffix = 'ffff';
+      expect(node.getLabelSuffix()).to.equal('');
+      expect(node.getLabelSuffix()).to.equal('');
+      node.setLabelSuffix(labelSuffix);
+      expect(node.getLabelSuffix()).to.equal(labelSuffix);
+      node.resetLabelSuffix();
+      expect(node.getLabelSuffix()).to.equal('');
+    });
+  });
+
+  describe("label", () => {
+    it("get", () => {
+      const labelRadix = '0';
+      const labelSuffix = 'ffff';
+      expect(node.getLabel()).to.equal('');
+      node.setLabelRadix(labelRadix);
+      expect(node.getLabel()).to.equal(labelRadix);
+      node.setLabelSuffix(labelSuffix);
+      expect(node.getLabel()).to.equal(labelRadix + labelSuffix);
+      node.resetLabelSuffix();
+      expect(node.getLabel()).to.equal(labelRadix);
+      node.resetLabelRadix();
+      expect(node.getLabel()).to.equal('');
+    });
+  });
+
+  describe("parent", () => {
+    it("get / set / has / reset", () => {
+      const parent = new RadixNode();
+      expect(node.getParent()).to.equal(null);
+      expect(node.hasParent()).to.equal(false);
+      node.setParent(parent);
+      expect(node.getParent()).to.equal(parent);
+      expect(node.hasParent()).to.equal(true);
+      node.resetParent();
+      expect(node.getParent()).to.equal(null);
+      expect(node.hasParent()).to.equal(false);
+    });
+  });
+
+  describe("child", () => {
+    it("set / delete with a child with invalid labels", () => {
+      const labelRadix = '0';
+      const labelSuffix = 'ffff';
+      const child = new RadixNode();
+
+      // setChild() with invalid label radix
+      expect(node.setChild(undefined, labelSuffix, child)).to.equal(false);
+      expect(node.setChild(null, labelSuffix, child)).to.equal(false);
+      expect(node.setChild(true, labelSuffix, child)).to.equal(false);
+      expect(node.setChild(1, labelSuffix, child)).to.equal(false);
+      expect(node.setChild('', labelSuffix, child)).to.equal(false);
+      expect(node.setChild('00', labelSuffix, child)).to.equal(false);
+
+      // setChild() with invalid label suffix
+      expect(node.setChild(labelRadix, undefined, child)).to.equal(false);
+      expect(node.setChild(labelRadix, null, child)).to.equal(false);
+      expect(node.setChild(labelRadix, true, child)).to.equal(false);
+      expect(node.setChild(labelRadix, 1, child)).to.equal(false);
+
+      // deleteChild() with invalid label radix
+      expect(node.deleteChild(undefined)).to.equal(false);
+      expect(node.deleteChild(null)).to.equal(false);
+      expect(node.deleteChild(true)).to.equal(false);
+      expect(node.deleteChild(1)).to.equal(false);
+    });
+
+    it("get / set / has / delete with a child with valid labels", () => {
+      const labelRadix = '0';
+      const labelSuffix = 'ffff';
+      const child = new RadixNode();
+
+      expect(node.hasStateNode()).to.equal(false);
+      expect(node.getLabelRadix()).to.equal('');
+      expect(node.getLabelSuffix()).to.equal('');
+      expect(node.hasParent()).to.equal(false);
+      expect(node.hasChild()).to.equal(false);
+      expect(node.getChild(labelRadix)).to.equal(null);
+      assert.deepEqual(node.getChildLabelRadices(), []);
+      assert.deepEqual(node.getChildNodes(), []);
+      expect(node.numChildren()).to.equal(0);
+
+      expect(child.hasStateNode()).to.equal(false);
+      expect(child.getLabelRadix()).to.equal('');
+      expect(child.getLabelSuffix()).to.equal('');
+      expect(child.hasParent()).to.equal(false);
+      expect(child.hasChild()).to.equal(false);
+      assert.deepEqual(child.getChildLabelRadices(), []);
+      assert.deepEqual(child.getChildNodes(), []);
+      expect(child.numChildren()).to.equal(0);
+
+      // setChild()
+      node.setChild(labelRadix, labelSuffix, child);
+
+      expect(node.hasStateNode()).to.equal(false);
+      expect(node.getLabelRadix()).to.equal('');
+      expect(node.getLabelSuffix()).to.equal('');
+      expect(node.hasParent()).to.equal(false);
+      expect(node.hasChild()).to.equal(true);
+      expect(node.getChild(labelRadix)).to.equal(child);
+      assert.deepEqual(node.getChildLabelRadices(), [labelRadix]);
+      assert.deepEqual(node.getChildNodes(), [child]);
+      expect(node.numChildren()).to.equal(1);
+
+      expect(child.hasStateNode()).to.equal(false);
+      expect(child.getLabelRadix()).to.equal(labelRadix);
+      expect(child.getLabelSuffix()).to.equal(labelSuffix);
+      expect(child.hasParent()).to.equal(true);
+      expect(child.getParent()).to.equal(node);
+      expect(child.hasChild()).to.equal(false);
+      assert.deepEqual(child.getChildLabelRadices(), []);
+      assert.deepEqual(child.getChildNodes(), []);
+      expect(child.numChildren()).to.equal(0);
+
+      // deleteChild()
+      node.deleteChild(labelRadix);
+
+      expect(node.hasStateNode()).to.equal(false);
+      expect(node.getLabelRadix()).to.equal('');
+      expect(node.getLabelSuffix()).to.equal('');
+      expect(node.hasParent()).to.equal(false);
+      expect(node.hasChild()).to.equal(false);
+      expect(node.getChild(labelRadix)).to.equal(null);
+      assert.deepEqual(node.getChildLabelRadices(), []);
+      assert.deepEqual(node.getChildNodes(), []);
+      expect(node.numChildren()).to.equal(0);
+
+      expect(child.hasStateNode()).to.equal(false);
+      expect(child.getLabelRadix()).to.equal('');
+      expect(child.getLabelSuffix()).to.equal('');
+      expect(child.hasParent()).to.equal(false);
+      expect(child.hasChild()).to.equal(false);
+      assert.deepEqual(child.getChildLabelRadices(), []);
+      assert.deepEqual(child.getChildNodes(), []);
+      expect(child.numChildren()).to.equal(0);
+    });
+
+    it("get / set / has / delete with children with valid labels", () => {
+      const labelRadix1 = '0';
+      const labelSuffix1 = '0000';
+      const child1 = new RadixNode();
+
+      const labelRadix2 = '1';
+      const labelSuffix2 = '1111';
+      const child2 = new RadixNode();
+
+      // setChild() with child1
+      node.setChild(labelRadix1, labelSuffix1, child1);
+      expect(node.hasStateNode()).to.equal(false);
+      expect(node.getLabelRadix()).to.equal('');
+      expect(node.getLabelSuffix()).to.equal('');
+      expect(node.hasParent()).to.equal(false);
+      expect(node.hasChild()).to.equal(true);
+      expect(node.getChild(labelRadix1)).to.equal(child1);
+      expect(node.getChild(labelRadix2)).to.equal(null);
+      assert.deepEqual(node.getChildLabelRadices(), [labelRadix1]);
+      assert.deepEqual(node.getChildNodes(), [child1]);
+      expect(node.numChildren()).to.equal(1);
+
+      expect(child1.hasStateNode()).to.equal(false);
+      expect(child1.getLabelRadix()).to.equal(labelRadix1);
+      expect(child1.getLabelSuffix()).to.equal(labelSuffix1);
+      expect(child1.hasParent()).to.equal(true);
+      expect(child1.getParent()).to.equal(node);
+      expect(child1.hasChild()).to.equal(false);
+      assert.deepEqual(child1.getChildLabelRadices(), []);
+      assert.deepEqual(child1.getChildNodes(), []);
+      expect(child1.numChildren()).to.equal(0);
+
+      // setChild() with child2
+      node.setChild(labelRadix2, labelSuffix2, child2);
+
+      expect(node.hasStateNode()).to.equal(false);
+      expect(node.getLabelRadix()).to.equal('');
+      expect(node.getLabelSuffix()).to.equal('');
+      expect(node.hasParent()).to.equal(false);
+      expect(node.hasChild()).to.equal(true);
+      expect(node.getChild(labelRadix1)).to.equal(child1);
+      expect(node.getChild(labelRadix2)).to.equal(child2);
+      assert.deepEqual(node.getChildLabelRadices(), [labelRadix1, labelRadix2]);
+      assert.deepEqual(node.getChildNodes(), [child1, child2]);
+      expect(node.numChildren()).to.equal(2);
+
+      expect(child1.hasStateNode()).to.equal(false);
+      expect(child1.getLabelRadix()).to.equal(labelRadix1);
+      expect(child1.getLabelSuffix()).to.equal(labelSuffix1);
+      expect(child1.hasParent()).to.equal(true);
+      expect(child1.getParent()).to.equal(node);
+      expect(child1.hasChild()).to.equal(false);
+      assert.deepEqual(child1.getChildLabelRadices(), []);
+      assert.deepEqual(child1.getChildNodes(), []);
+      expect(child1.numChildren()).to.equal(0);
+
+      expect(child2.hasStateNode()).to.equal(false);
+      expect(child1.getLabelRadix()).to.equal(labelRadix1);
+      expect(child1.getLabelSuffix()).to.equal(labelSuffix1);
+      expect(child2.hasParent()).to.equal(true);
+      expect(child2.getParent()).to.equal(node);
+      expect(child2.hasChild()).to.equal(false);
+      assert.deepEqual(child2.getChildLabelRadices(), []);
+      assert.deepEqual(child2.getChildNodes(), []);
+      expect(child2.numChildren()).to.equal(0);
+
+      // deleteChild() with child1
+      node.deleteChild(labelRadix1);
+
+      expect(node.hasStateNode()).to.equal(false);
+      expect(node.getLabelRadix()).to.equal('');
+      expect(node.getLabelSuffix()).to.equal('');
+      expect(node.hasParent()).to.equal(false);
+      expect(node.getChild(labelRadix1)).to.equal(null);
+      expect(node.getChild(labelRadix2)).to.equal(child2);
+      expect(node.hasChild()).to.equal(true);
+      assert.deepEqual(node.getChildLabelRadices(), [labelRadix2]);
+      assert.deepEqual(node.getChildNodes(), [child2]);
+      expect(node.numChildren()).to.equal(1);
+
+      expect(child1.hasStateNode()).to.equal(false);
+      expect(child1.getLabelRadix()).to.equal('');
+      expect(child1.getLabelSuffix()).to.equal('');
+      expect(child1.hasParent()).to.equal(false);
+      expect(child1.hasChild()).to.equal(false);
+      assert.deepEqual(child1.getChildLabelRadices(), []);
+      assert.deepEqual(child1.getChildNodes(), []);
+      expect(child1.numChildren()).to.equal(0);
+
+      expect(child2.hasStateNode()).to.equal(false);
+      expect(child2.getLabelRadix()).to.equal(labelRadix2);
+      expect(child2.getLabelSuffix()).to.equal(labelSuffix2);
+      expect(child2.hasParent()).to.equal(true);
+      expect(child2.getParent()).to.equal(node);
+      expect(child2.hasChild()).to.equal(false);
+      assert.deepEqual(child2.getChildLabelRadices(), []);
+      assert.deepEqual(child2.getChildNodes(), []);
+      expect(child2.numChildren()).to.equal(0);
+    });
+  });
+
+  describe("proofHash", () => {
+    const labelRadix1 = '1';
+    const labelSuffix1 = '100';
+    let child1;
+
+    const labelRadix2 = '2';
+    const labelSuffix2 = '200';
+    let child2;
+
+    const labelRadix11 = '1';
+    const labelSuffix11 = '110';
+    let child11;
+
+    const labelRadix12 = '2';
+    const labelSuffix12 = '120';
+    let child12;
+
+    const labelRadix21 = '1';
+    const labelSuffix21 = '210';
+    let child21;
+
+    const labelRadix22 = '2';
+    const labelSuffix22 = '220';
+    let child22;
+
+    let stateNode;
+    const stateNodePH = 'stateNodePH';
+
+    let stateNode1;
+    const stateNodePH1 = 'stateNodePH1';
+
+    let stateNode2;
+    const stateNodePH2 = 'stateNodePH2';
+
+    let stateNode11;
+    const stateNodePH11 = 'stateNodePH11';
+
+    let stateNode12;
+    const stateNodePH12 = 'stateNodePH12';
+
+    let stateNode21;
+    const stateNodePH21 = 'stateNodePH21';
+
+    let stateNode22;
+    const stateNodePH22 = 'stateNodePH22';
+
+    beforeEach(() => {
+      child1 = new RadixNode();
+      child2 = new RadixNode();
+      child11 = new RadixNode();
+      child12 = new RadixNode();
+      child21 = new RadixNode();
+      child22 = new RadixNode();
+
+      stateNode = new StateNode();
+      stateNode.setProofHash(stateNodePH);
+      node.setStateNode(stateNode);
+
+      stateNode1 = new StateNode();
+      stateNode1.setProofHash(stateNodePH1);
+      child1.setStateNode(stateNode1);
+
+      stateNode11 = new StateNode();
+      stateNode11.setProofHash(stateNodePH11);
+      child11.setStateNode(stateNode11);
+
+      stateNode12 = new StateNode();
+      stateNode12.setProofHash(stateNodePH12);
+      child12.setStateNode(stateNode12);
+
+      stateNode21 = new StateNode();
+      stateNode21.setProofHash(stateNodePH21);
+      child21.setStateNode(stateNode21);
+
+      stateNode22 = new StateNode();
+      stateNode22.setProofHash(stateNodePH22);
+      child22.setStateNode(stateNode22);
+    })
+
+    it("get / set / has / reset", () => {
+      const proofHash = 'proofHash';
+
+      expect(node.getProofHash()).to.equal(null);
+      node.setProofHash(proofHash);
+      expect(node.getProofHash()).to.equal(proofHash);
+      node.resetProofHash();
+      expect(node.getProofHash()).to.equal(null);
+    });
+
+    it("build", () => {
+      const childPH1 = 'childPH1';
+      const childPH2 = 'childPH2';
+
+      child1.setProofHash(childPH1);
+      child2.setProofHash(childPH2);
+
+      node.setChild(labelRadix1, labelSuffix1, child1);
+      node.setChild(labelRadix2, labelSuffix2, child2);
+
+      assert.deepEqual(node.toJsObject(true), {
+        "1100": {
+          ".label": null,
+          ".proof_hash": "stateNodePH1",
+          ".radix_ph": "childPH1"
+        },
+        "2200": {
+          ".radix_ph": "childPH2"
+        },
+        ".label": null,
+        ".proof_hash": "stateNodePH",
+        ".radix_ph": null
+      });
+
+      // With stateNode
+      node.setStateNode(stateNode);
+      const preimage2 = `${stateNodePH}${HASH_DELIMITER}${HASH_DELIMITER}` +
+          `${labelRadix1}${labelSuffix1}${HASH_DELIMITER}${childPH1}` +
+          `${HASH_DELIMITER}${labelRadix2}${labelSuffix2}${HASH_DELIMITER}${childPH2}`;
+      const proofHash2 = CommonUtil.hashString(preimage2);
+      expect(node._buildProofHash()).to.equal(proofHash2)
+
+      // Without stateNode
+      node.resetStateNode();
+      const preimage1 = `${HASH_DELIMITER}${HASH_DELIMITER}` +
+          `${labelRadix1}${labelSuffix1}${HASH_DELIMITER}${childPH1}` +
+          `${HASH_DELIMITER}${labelRadix2}${labelSuffix2}${HASH_DELIMITER}${childPH2}`;
+      const proofHash1 = CommonUtil.hashString(preimage1);
+      expect(node._buildProofHash()).to.equal(proofHash1)
+    });
+
+    it("update / verify", () => {
+      const childPH1 = 'childPH1';
+      const childPH2 = 'childPH2';
+
+      child1.setProofHash(childPH1);
+      child2.setProofHash(childPH2);
+
+      node.setChild(labelRadix1, labelSuffix1, child1);
+      node.setChild(labelRadix2, labelSuffix2, child2);
+
+      assert.deepEqual(node.toJsObject(true), {
+        "1100": {
+          ".label": null,
+          ".proof_hash": "stateNodePH1",
+          ".radix_ph": "childPH1"
+        },
+        "2200": {
+          ".radix_ph": "childPH2"
+        },
+        ".label": null,
+        ".proof_hash": "stateNodePH",
+        ".radix_ph": null
+      });
+
+      node.resetProofHash();
+      expect(node.verifyProofHash()).to.equal(false);
+      node.updateProofHash();
+      expect(node.verifyProofHash()).to.equal(true);
+      expect(node.getProofHash()).to.equal(node._buildProofHash());
+    });
+
+    it("updateProofHashForRadixSubtree", () => {
+      node.setStateNode(stateNode);
+      node.setChild(labelRadix1, labelSuffix1, child1);
+      node.setChild(labelRadix2, labelSuffix2, child2);
+      child1.setChild(labelRadix11, labelSuffix11, child11);
+      child1.setChild(labelRadix12, labelSuffix12, child12);
+      child2.setChild(labelRadix21, labelSuffix21, child21);
+      child2.setChild(labelRadix22, labelSuffix22, child22);
+
+      assert.deepEqual(node.toJsObject(true), {
+        "1100": {
+          "1110": {
+            ".label": null,
+            ".proof_hash": "stateNodePH11",
+            ".radix_ph": null
+          },
+          "2120": {
+            ".label": null,
+            ".proof_hash": "stateNodePH12",
+            ".radix_ph": null
+          },
+          ".label": null,
+          ".proof_hash": "stateNodePH1",
+          ".radix_ph": null
+        },
+        "2200": {
+          "1210": {
+            ".label": null,
+            ".proof_hash": "stateNodePH21",
+            ".radix_ph": null
+          },
+          "2220": {
+            ".label": null,
+            ".proof_hash": "stateNodePH22",
+            ".radix_ph": null
+          },
+          ".radix_ph": null
+        },
+        ".label": null,
+        ".proof_hash": "stateNodePH",
+        ".radix_ph": null
+      });
+
+      // initial status
+      expect(node.verifyProofHash()).to.equal(false);
+      expect(child1.verifyProofHash()).to.equal(false);
+      expect(child2.verifyProofHash()).to.equal(false);
+      expect(child11.verifyProofHash()).to.equal(false);
+      expect(child12.verifyProofHash()).to.equal(false);
+      expect(child21.verifyProofHash()).to.equal(false);
+      expect(child22.verifyProofHash()).to.equal(false);
+
+      // set
+      expect(node.updateProofHashForRadixSubtree()).to.equal(7);
+      expect(node.verifyProofHash()).to.equal(true);
+      expect(child1.verifyProofHash()).to.equal(true);
+      expect(child2.verifyProofHash()).to.equal(true);
+      expect(child11.verifyProofHash()).to.equal(true);
+      expect(child12.verifyProofHash()).to.equal(true);
+      expect(child21.verifyProofHash()).to.equal(true);
+      expect(child22.verifyProofHash()).to.equal(true);
+
+      // change of a state node's proof hash
+      stateNode12.setProofHash('another PH');
+      expect(node.verifyProofHash()).to.equal(true);
+      expect(child1.verifyProofHash()).to.equal(true);
+      expect(child2.verifyProofHash()).to.equal(true);
+      expect(child11.verifyProofHash()).to.equal(true);
+      expect(child12.verifyProofHash()).to.equal(false);
+      expect(child21.verifyProofHash()).to.equal(true);
+      expect(child22.verifyProofHash()).to.equal(true);
+    });
+
+    it("updateProofHashForRadixPath", () => {
+      node.setStateNode(stateNode);
+      node.setChild(labelRadix1, labelSuffix1, child1);
+      node.setChild(labelRadix2, labelSuffix2, child2);
+      child1.setChild(labelRadix11, labelSuffix11, child11);
+      child1.setChild(labelRadix12, labelSuffix12, child12);
+      child2.setChild(labelRadix21, labelSuffix21, child21);
+      child2.setChild(labelRadix22, labelSuffix22, child22);
+
+      assert.deepEqual(node.toJsObject(true), {
+        "1100": {
+          "1110": {
+            ".label": null,
+            ".proof_hash": "stateNodePH11",
+            ".radix_ph": null
+          },
+          "2120": {
+            ".label": null,
+            ".proof_hash": "stateNodePH12",
+            ".radix_ph": null
+          },
+          ".label": null,
+          ".proof_hash": "stateNodePH1",
+          ".radix_ph": null
+        },
+        "2200": {
+          "1210": {
+            ".label": null,
+            ".proof_hash": "stateNodePH21",
+            ".radix_ph": null
+          },
+          "2220": {
+            ".label": null,
+            ".proof_hash": "stateNodePH22",
+            ".radix_ph": null
+          },
+          ".radix_ph": null
+        },
+        ".label": null,
+        ".proof_hash": "stateNodePH",
+        ".radix_ph": null
+      });
+
+      // initial status
+      expect(node.verifyProofHash()).to.equal(false);
+      expect(child1.verifyProofHash()).to.equal(false);
+      expect(child2.verifyProofHash()).to.equal(false);
+      expect(child11.verifyProofHash()).to.equal(false);
+      expect(child12.verifyProofHash()).to.equal(false);
+      expect(child21.verifyProofHash()).to.equal(false);
+      expect(child22.verifyProofHash()).to.equal(false);
+
+      // update
+      expect(child21.updateProofHashForRadixPath()).to.equal(3);
+      expect(node.verifyProofHash()).to.equal(true);
+      expect(child1.verifyProofHash()).to.equal(false);
+      expect(child2.verifyProofHash()).to.equal(true);
+      expect(child11.verifyProofHash()).to.equal(false);
+      expect(child12.verifyProofHash()).to.equal(false);
+      expect(child21.verifyProofHash()).to.equal(true);
+      expect(child22.verifyProofHash()).to.equal(false);
+    });
+
+    it("verifyProofHashForRadixSubtree", () => {
+      node.setStateNode(stateNode);
+      node.setChild(labelRadix1, labelSuffix1, child1);
+      node.setChild(labelRadix2, labelSuffix2, child2);
+      child1.setChild(labelRadix11, labelSuffix11, child11);
+      child1.setChild(labelRadix12, labelSuffix12, child12);
+      child2.setChild(labelRadix21, labelSuffix21, child21);
+      child2.setChild(labelRadix22, labelSuffix22, child22);
+
+      assert.deepEqual(node.toJsObject(true), {
+        "1100": {
+          "1110": {
+            ".label": null,
+            ".proof_hash": "stateNodePH11",
+            ".radix_ph": null
+          },
+          "2120": {
+            ".label": null,
+            ".proof_hash": "stateNodePH12",
+            ".radix_ph": null
+          },
+          ".label": null,
+          ".proof_hash": "stateNodePH1",
+          ".radix_ph": null
+        },
+        "2200": {
+          "1210": {
+            ".label": null,
+            ".proof_hash": "stateNodePH21",
+            ".radix_ph": null
+          },
+          "2220": {
+            ".label": null,
+            ".proof_hash": "stateNodePH22",
+            ".radix_ph": null
+          },
+          ".radix_ph": null
+        },
+        ".label": null,
+        ".proof_hash": "stateNodePH",
+        ".radix_ph": null
+      });
+
+      // initial status
+      expect(node.verifyProofHashForRadixSubtree()).to.equal(false);
+
+      // set
+      expect(node.updateProofHashForRadixSubtree()).to.equal(7);
+      expect(node.verifyProofHashForRadixSubtree()).to.equal(true);
+
+      // change of a state node's proof hash
+      stateNode21.setProofHash('another PH');
+      expect(node.verifyProofHashForRadixSubtree()).to.equal(false);
+
+      // update
+      expect(child21.updateProofHashForRadixPath()).to.equal(3);
+      expect(node.verifyProofHashForRadixSubtree()).to.equal(true);
+    });
+
+    it("getProofOfRadixNode", () => {
+      node.setStateNode(stateNode);
+      node.setChild(labelRadix1, labelSuffix1, child1);
+      node.setChild(labelRadix2, labelSuffix2, child2);
+      child1.setChild(labelRadix11, labelSuffix11, child11);
+      child1.setChild(labelRadix12, labelSuffix12, child12);
+      child2.setChild(labelRadix21, labelSuffix21, child21);
+      child2.setChild(labelRadix22, labelSuffix22, child22);
+
+      expect(node.updateProofHashForRadixSubtree()).to.equal(7);
+
+      assert.deepEqual(node.toJsObject(true), {
+        "1100": {
+          "1110": {
+            ".label": null,
+            ".proof_hash": "stateNodePH11",
+            ".radix_ph": "0xac8e0ca829cea8d80a79260078fb8e1b38a05b6d087c72a1c92f63849a47b96b"
+          },
+          "2120": {
+            ".label": null,
+            ".proof_hash": "stateNodePH12",
+            ".radix_ph": "0x7fc53637a6ff6b7efa8cf7c9ba95552ed7479262ad8c07a61b4d2b1e8002d360"
+          },
+          ".label": null,
+          ".proof_hash": "stateNodePH1",
+          ".radix_ph": "0x58b89a07baf039f5a5420aeafed213b7abe18c3f1537e9626628719f56ab5434"
+        },
+        "2200": {
+          "1210": {
+            ".label": null,
+            ".proof_hash": "stateNodePH21",
+            ".radix_ph": "0xa8c806fde336879bd0cb320c809ad8a1f6e1e526711ed239eb216f83e4fb19d7"
+          },
+          "2220": {
+            ".label": null,
+            ".proof_hash": "stateNodePH22",
+            ".radix_ph": "0x0dd8afcb4c2839ff30e6872c7268f9ed687fd53c52ce78f0330de82d5b33a0a2"
+          },
+          ".radix_ph": "0xb822c6a20a4128f025019f9f03cb802f86998f48073118b132fd40fbd1620fed"
+        },
+        ".label": null,
+        ".proof_hash": "stateNodePH",
+        ".radix_ph": "0xf29196bc2c6609216445dc878baf97143463a00c9e03c6af0ba6d38a2817b3b3"
+      });
+
+      const label11 = labelRadix11 + labelSuffix11;
+      const label21 = labelRadix21 + labelSuffix21;
+
+      // on a node with state node value with child label and child proof
+      assert.deepEqual(child1.getProofOfRadixNode(label11, 'childProof1'), {
+        "1110": "childProof1",
+        "2120": {
+          ".radix_ph": "0x7fc53637a6ff6b7efa8cf7c9ba95552ed7479262ad8c07a61b4d2b1e8002d360"
+        },
+        ".label": null,
+        ".proof_hash": "stateNodePH1",
+        ".radix_ph": "0x58b89a07baf039f5a5420aeafed213b7abe18c3f1537e9626628719f56ab5434"
+      });
+
+      // on a node without state node value with child label and child proof
+      assert.deepEqual(child2.getProofOfRadixNode(label21, 'childProof2'), {
+        "1210": "childProof2",
+        "2220": {
+          ".radix_ph": "0x0dd8afcb4c2839ff30e6872c7268f9ed687fd53c52ce78f0330de82d5b33a0a2"
+        },
+        ".radix_ph": "0xb822c6a20a4128f025019f9f03cb802f86998f48073118b132fd40fbd1620fed"
+      });
+
+      // on a node with state node value with state label/proof
+      assert.deepEqual(child1.getProofOfRadixNode(null, null, 'stateLabel1', 'stateProof1'), {
+        ".label": "stateLabel1",
+        ".proof_hash": "stateProof1",
+        ".radix_ph": "0x58b89a07baf039f5a5420aeafed213b7abe18c3f1537e9626628719f56ab5434"
+      });
+
+      // on a node without state node value with state label/proof
+      assert.deepEqual(child2.getProofOfRadixNode(null, null, 'stateLabel1', 'stateProof2'), {
+        ".radix_ph": "0xb822c6a20a4128f025019f9f03cb802f86998f48073118b132fd40fbd1620fed"
+      });
+    });
+  });
+
+  describe("utils", () => {
+    let stateNode1;
+    let stateNode2;
+    let stateNode21;
+    let stateNode22;
+    let child1;
+    let child2;
+    let child21;
+    let child22;
+
+    beforeEach(() => {
+      stateNode1 = new StateNode();
+      stateNode1.setProofHash('stateNodePH1');
+      stateNode2 = new StateNode();
+      stateNode2.setProofHash('stateNodePH2');
+      stateNode21 = new StateNode();
+      stateNode21.setProofHash('stateNodePH21');
+      stateNode22 = new StateNode();
+      stateNode22.setProofHash('stateNodePH22');
+
+      child1 = new RadixNode();
+      child1.setProofHash('childPH1');
+      child1.setStateNode(stateNode1);
+
+      child2 = new RadixNode();
+      child2.setProofHash('childPH2');
+      child2.setStateNode(stateNode2);
+
+      child21 = new RadixNode();
+      child21.setProofHash('childPH21');
+      child21.setStateNode(stateNode21);
+
+      child22 = new RadixNode();
+      child22.setProofHash('childPH22');
+      child22.setStateNode(stateNode22);
+
+      node.setChild('0', '001', child1);
+      node.setChild('1', '002', child2);
+      child2.setChild('2', '021', child21);
+      child2.setChild('3', '022', child22);
+    });
+
+    it("copyFrom", () => {
+      const newNode = new RadixNode();
+      newNode.copyFrom(node);
+      assert.deepEqual(newNode.toJsObject(), {
+        "1002": {
+          "2021": {
+            ".label": null,
+            ".proof_hash": "stateNodePH21"
+          },
+          "3022": {
+            ".label": null,
+            ".proof_hash": "stateNodePH22"
+          },
+          ".label": null,
+          ".proof_hash": "stateNodePH2"
+        },
+        "0001": {
+          ".label": null,
+          ".proof_hash": "stateNodePH1"
+        }
+      });
+    });
+
+    it("toJsObject", () => {
+      assert.deepEqual(node.toJsObject(), {
+        "1002": {
+          "2021": {
+            ".label": null,
+            ".proof_hash": "stateNodePH21"
+          },
+          "3022": {
+            ".label": null,
+            ".proof_hash": "stateNodePH22"
+          },
+          ".label": null,
+          ".proof_hash": "stateNodePH2"
+        },
+        "0001": {
+          ".label": null,
+          ".proof_hash": "stateNodePH1"
+        }
+      });
+      assert.deepEqual(node.toJsObject(true, true), {
+        "1002": {
+          "2021": {
+            ".label": null,
+            ".proof_hash": "stateNodePH21",
+            ".radix_ph": "childPH21"
+          },
+          "3022": {
+            ".label": null,
+            ".proof_hash": "stateNodePH22",
+            ".radix_ph": "childPH22"
+          },
+          ".label": null,
+          ".proof_hash": "stateNodePH2",
+          ".radix_ph": "childPH2"
+        },
+        ".radix_ph": null,
+        "0001": {
+          ".label": null,
+          ".proof_hash": "stateNodePH1",
+          ".radix_ph": "childPH1"
+        }
+      });
+    });
+  });
+});
diff --git a/unittest/radix-tree.test.js b/unittest/radix-tree.test.js
new file mode 100644
index 000000000..f0e70334b
--- /dev/null
+++ b/unittest/radix-tree.test.js
@@ -0,0 +1,1814 @@
+const RadixTree = require('../db/radix-tree');
+const RadixNode = require('../db/radix-node');
+const StateNode = require('../db/state-node');
+const chai = require('chai');
+const expect = chai.expect;
+const assert = chai.assert;
+
+describe("radix-tree", () => {
+  describe("Utils", () => {
+    it("_toHexLabel", () => {
+      const tree = new RadixTree();
+      expect(tree._toHexLabel('0x1234567890abcdef')).to.equal('1234567890abcdef');
+      expect(tree._toHexLabel('aAzZ')).to.equal('61417a5a');
+    });
+
+    it("_matchLabelSuffix with empty label suffix", () => {
+      const hexLabel = '1234abcd';
+      const radixNode = new RadixNode();
+      radixNode.setLabelSuffix('');
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 0)).to.equal(true);
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 1)).to.equal(true);
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 2)).to.equal(true);
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 3)).to.equal(true);
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 4)).to.equal(true);
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 5)).to.equal(true);
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 6)).to.equal(true);
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 7)).to.equal(true);
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 8)).to.equal(true);
+      expect(RadixTree._matchLabelSuffix(radixNode, '', 0)).to.equal(true);
+    });
+
+    it("_matchLabelSuffix with non-empty label suffix", () => {
+      const hexLabel = '1234abcd';
+      const radixNode = new RadixNode();
+      // a shorter length
+      radixNode.setLabelSuffix('ab');
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 3)).to.equal(false);
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 4)).to.equal(true);
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 5)).to.equal(false);
+
+      // the same length
+      radixNode.setLabelSuffix('abcd');
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 3)).to.equal(false);
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 4)).to.equal(true);
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 5)).to.equal(false);
+
+      // a longer length
+      radixNode.setLabelSuffix('abcd123');
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 3)).to.equal(false);
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 4)).to.equal(false);
+      expect(RadixTree._matchLabelSuffix(radixNode, hexLabel, 5)).to.equal(false);
+    });
+
+    it("_getCommonPrefix", () => {
+      expect(RadixTree._getCommonPrefix('1234567890abcdef', '1234567890abcdef'))
+          .to.equal('1234567890abcdef');
+      expect(RadixTree._getCommonPrefix('1234567890000000', '1234567890abcdef'))
+          .to.equal('1234567890');
+      expect(RadixTree._getCommonPrefix('1234567890abcdef', '1234567890000000'))
+          .to.equal('1234567890');
+      expect(RadixTree._getCommonPrefix('1234567890', '1234567890abcdef'))
+          .to.equal('1234567890');
+      expect(RadixTree._getCommonPrefix('1234567890abcdef', '1234567890'))
+          .to.equal('1234567890');
+      expect(RadixTree._getCommonPrefix('1234567890abcdef', '01234567890abcdef'))
+          .to.equal('');
+    });
+
+    it("_setChildWithLabel with empty label suffix", () => {
+      const node = new RadixNode();
+      const child = new RadixNode();
+
+      expect(RadixTree._setChildWithLabel(node, '1', child)).to.equal(true);
+      assert.deepEqual(node.getChild('1'), child);
+      expect(child.getLabelRadix()).to.equal('1');
+      expect(child.getLabelSuffix()).to.equal('');
+    });
+
+    it("_setChildWithLabel with non-empty label suffix", () => {
+      const node = new RadixNode();
+      const child = new RadixNode();
+
+      expect(RadixTree._setChildWithLabel(node, '1234567890abcdef', child)).to.equal(true);
+      expect(node.hasChild('1')).to.equal(true);
+      assert.deepEqual(node.getChild('1'), child);
+      expect(child.getLabelRadix()).to.equal('1');
+      expect(child.getLabelSuffix()).to.equal('234567890abcdef');
+    });
+  });
+
+  describe("Map APIs", () => {
+    let tree;
+
+    beforeEach(() => {
+      tree = new RadixTree();
+    })
+
+    describe("_setInMap / _deleteFromMap / _hasInMap / _getFromMap / labels / stateNodes / size", () => {
+      const stateNode1 = new StateNode();
+      const stateNode2 = new StateNode();
+
+      it("with non-empty label suffices", () => {
+        const label1 = '0x000111aaa';
+        const label2 = '0x000111bbb';
+
+        expect(tree._getFromMap(label1)).to.equal(null);
+        expect(tree._getFromMap(label2)).to.equal(null);
+        expect(tree._hasInMap(label1)).to.equal(false);
+        expect(tree._hasInMap(label2)).to.equal(false);
+        assert.deepEqual(tree.labels(), []);
+        assert.deepEqual(tree.stateNodes(), []);
+        assert.deepEqual(tree.size(), 0);
+
+        // set first node
+        tree._setInMap(label1, stateNode1);
+
+        expect(tree._getFromMap(label1)).to.equal(stateNode1);
+        expect(tree._getFromMap(label2)).to.equal(null);
+        expect(tree._hasInMap(label1)).to.equal(true);
+        expect(tree._hasInMap(label2)).to.equal(false);
+        assert.deepEqual(tree.labels(), [label1]);
+        assert.deepEqual(tree.stateNodes(), [stateNode1]);
+        assert.deepEqual(tree.size(), 1);
+
+        // set second node
+        tree._setInMap(label2, stateNode2);
+
+        expect(tree._getFromMap(label1)).to.equal(stateNode1);
+        expect(tree._getFromMap(label2)).to.equal(stateNode2);
+        expect(tree._hasInMap(label1)).to.equal(true);
+        expect(tree._hasInMap(label2)).to.equal(true);
+        assert.deepEqual(tree.labels(), [label1, label2]);
+        assert.deepEqual(tree.stateNodes(), [stateNode1, stateNode2]);
+        assert.deepEqual(tree.size(), 2);
+
+        // delete first node
+        tree._deleteFromMap(label1);
+
+        expect(tree._getFromMap(label1)).to.equal(null);
+        expect(tree._getFromMap(label2)).to.equal(stateNode2);
+        expect(tree._hasInMap(label1)).to.equal(false);
+        expect(tree._hasInMap(label2)).to.equal(true);
+        assert.deepEqual(tree.labels(), [label2]);
+        assert.deepEqual(tree.stateNodes(), [stateNode2]);
+        assert.deepEqual(tree.size(), 1);
+
+        // delete second node
+        tree._deleteFromMap(label2);
+
+        expect(tree._getFromMap(label1)).to.equal(null);
+        expect(tree._getFromMap(label2)).to.equal(null);
+        expect(tree._hasInMap(label1)).to.equal(false);
+        expect(tree._hasInMap(label2)).to.equal(false);
+        assert.deepEqual(tree.labels(), []);
+        assert.deepEqual(tree.stateNodes(), []);
+        assert.deepEqual(tree.size(), 0);
+      });
+    });
+
+    describe("_copyMapFrom", () => {
+      const stateNode1 = new StateNode();
+      const stateNode2 = new StateNode();
+
+      it("copy with non-empty label suffices", () => {
+        const label1 = '0x000111aaa';
+        const label2 = '0x000111bbb';
+
+        // set state nodes
+        tree._setInMap(label1, stateNode1);
+        tree._setInMap(label2, stateNode2);
+
+        const newTree = new RadixTree();
+        newTree._copyMapFrom(tree);
+        assert.deepEqual(newTree.labels(), [label1, label2]);
+        assert.deepEqual(newTree.stateNodes(), [stateNode1, stateNode2]);
+        assert.deepEqual(newTree.size(), 2);
+      });
+    });
+  });
+
+  describe("Tree APIs", () => {
+    let tree;
+
+    beforeEach(() => {
+      tree = new RadixTree();
+    })
+
+    describe("_setInTree / _deleteFromTree / _hasInTree / _getFromTree", () => {
+      let stateNode1;
+      let stateNode2;
+      let stateNode21;
+      let stateNode22;
+      let stateNodeInternal;
+
+      beforeEach(() => {
+        stateNode1 = new StateNode();
+        stateNode2 = new StateNode();
+        stateNode21 = new StateNode();
+        stateNode22 = new StateNode();
+        stateNodeInternal = new StateNode();
+      })
+
+      it("set with invalid state node", () => {
+        const invalidStateNode = new RadixNode();
+        const label = '0x000aaa';
+
+        expect(tree._setInTree(label, invalidStateNode)).to.equal(false);
+        expect(tree._setInTree(label, '')).to.equal(false);
+        expect(tree._setInTree(label, true)).to.equal(false);
+        expect(tree._setInTree(label, null)).to.equal(false);
+        expect(tree._setInTree(label, undefined)).to.equal(false);
+      });
+
+      it("set / delete without common label prefix - without label suffices", () => {
+        const label1 = '0xa';
+        const label2 = '0xb';
+
+        stateNode1._setLabel(label1);
+        stateNode2._setLabel(label2);
+
+        expect(tree._hasInTree(label1)).to.equal(false);
+        expect(tree._hasInTree(label2)).to.equal(false);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null
+        });
+
+        // set first node
+        tree._setInTree(label1, stateNode1);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(false);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "a": {
+            ".label": "0xa",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // set second node
+        tree._setInTree(label2, stateNode2);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "a": {
+            ".label": "0xa",
+            ".proof_hash": null,
+            ".radix_ph": null
+          },
+          "b": {
+            ".label": "0xb",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // delete first node
+        tree._deleteFromTree(label1);
+
+        expect(tree._hasInTree(label1)).to.equal(false);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "b": {
+            ".label": "0xb",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // delete second node
+        tree._deleteFromTree(label2);
+
+        expect(tree._hasInTree(label1)).to.equal(false);
+        expect(tree._hasInTree(label2)).to.equal(false);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null
+        });
+      });
+
+      it("set / delete without common label prefix - with label suffices", () => {
+        const label1 = '0xaaa';
+        const label2 = '0xbbb';
+
+        stateNode1._setLabel(label1);
+        stateNode2._setLabel(label2);
+
+        expect(tree._hasInTree(label1)).to.equal(false);
+        expect(tree._hasInTree(label2)).to.equal(false);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null
+        });
+
+        // set first node
+        tree._setInTree(label1, stateNode1);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(false);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "aaa": {
+            ".label": "0xaaa",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // set second node
+        tree._setInTree(label2, stateNode2);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "aaa": {
+            ".label": "0xaaa",
+            ".proof_hash": null,
+            ".radix_ph": null
+          },
+          "bbb": {
+            ".label": "0xbbb",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // delete first node
+        tree._deleteFromTree(label1);
+
+        expect(tree._hasInTree(label1)).to.equal(false);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "bbb": {
+            ".label": "0xbbb",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // delete second node
+        tree._deleteFromTree(label2);
+
+        expect(tree._hasInTree(label1)).to.equal(false);
+        expect(tree._hasInTree(label2)).to.equal(false);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null
+        });
+      });
+
+      it("set / delete without common label prefix - set with substring label suffix", () => {
+        const label1 = '0xaabb';
+        const label2 = '0xaa';
+
+        stateNode1._setLabel(label1);
+        stateNode2._setLabel(label2);
+
+        tree._setInTree(label1, stateNode1);
+        tree._setInTree(label2, stateNode2);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "aa": {
+            ".label": "0xaa",
+            ".proof_hash": null,
+            ".radix_ph": null,
+            "bb": {
+              ".label": "0xaabb",
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+      });
+
+      it("set / delete without common label prefix - set with superstring label suffix", () => {
+        const label1 = '0xaa';
+        const label2 = '0xaabb';
+
+        stateNode1._setLabel(label1);
+        stateNode2._setLabel(label2);
+
+        tree._setInTree(label1, stateNode1);
+        tree._setInTree(label2, stateNode2);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "aa": {
+            ".label": "0xaa",
+            ".proof_hash": null,
+            ".radix_ph": null,
+            "bb": {
+              ".label": "0xaabb",
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+      });
+
+      it("set / delete without common label prefix - set with exact-matched label suffix", () => {
+        const label = '0xaa';
+
+        stateNode1._setLabel(label);
+        stateNode2._setLabel(label + '_');  // tweak in order to distinguish
+
+        tree._setInTree(label, stateNode1);
+        tree._setInTree(label, stateNode2);
+
+        expect(tree._hasInTree(label)).to.equal(true);
+        expect(tree._getFromTree(label)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "aa": {
+            ".label": "0xaa_",
+            ".proof_hash": null,
+            ".radix_ph": null,
+          }
+        });
+      });
+
+      it("set / delete without common label prefix - set / delete with children", () => {
+        const label1 = '0xaaa';
+        const label2 = '0xbbb';
+        const label21 = '0xbbb111';
+        const label22 = '0xbbb222';
+
+        stateNode1._setLabel(label1);
+        stateNode2._setLabel(label2);
+        stateNode21._setLabel(label21);
+        stateNode22._setLabel(label22);
+
+        // set first node
+        tree._setInTree(label1, stateNode1);
+        // set second node
+        tree._setInTree(label2, stateNode2);
+        // set children
+        tree._setInTree(label21, stateNode21);
+        tree._setInTree(label22, stateNode22);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        expect(tree._hasInTree(label21)).to.equal(true);
+        expect(tree._getFromTree(label21)).to.equal(stateNode21);
+        expect(tree._hasInTree(label22)).to.equal(true);
+        expect(tree._getFromTree(label22)).to.equal(stateNode22);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "aaa": {
+            ".label": "0xaaa",
+            ".proof_hash": null,
+            ".radix_ph": null
+          },
+          "bbb": {
+            "111": {
+              ".label": "0xbbb111",
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "222": {
+              ".label": "0xbbb222",
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            ".label": "0xbbb",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // delete first node
+        tree._deleteFromTree(label1);
+
+        expect(tree._hasInTree(label1)).to.equal(false);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        expect(tree._hasInTree(label21)).to.equal(true);
+        expect(tree._getFromTree(label21)).to.equal(stateNode21);
+        expect(tree._hasInTree(label22)).to.equal(true);
+        expect(tree._getFromTree(label22)).to.equal(stateNode22);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "bbb": {
+            "111": {
+              ".label": "0xbbb111",
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "222": {
+              ".label": "0xbbb222",
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            ".label": "0xbbb",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+      });
+
+      it("set / delete without common label prefix - delete with only one child", () => {
+        const label2 = '0xbbb';
+        const label21 = '0xbbb111';
+
+        stateNode2._setLabel(label2);
+        stateNode21._setLabel(label21);
+
+        // set a node
+        tree._setInTree(label2, stateNode2);
+        // set a child
+        tree._setInTree(label21, stateNode21);
+
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        expect(tree._hasInTree(label21)).to.equal(true);
+        expect(tree._getFromTree(label21)).to.equal(stateNode21);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "bbb": {
+            "111": {
+              ".label": "0xbbb111",
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            ".label": "0xbbb",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // delete the node
+        tree._deleteFromTree(label2);
+
+        expect(tree._hasInTree(label2)).to.equal(false);
+        expect(tree._hasInTree(label21)).to.equal(true);
+        expect(tree._getFromTree(label21)).to.equal(stateNode21);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "bbb111": {
+            ".label": "0xbbb111",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+      });
+
+      it("set / delete with common label prefix - without label suffices", () => {
+        const label1 = '0x000a';
+        const label2 = '0x000b';
+
+        stateNode1._setLabel(label1);
+        stateNode2._setLabel(label2);
+
+        expect(tree._hasInTree(label1)).to.equal(false);
+        expect(tree._hasInTree(label2)).to.equal(false);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null
+        });
+
+        // set first node
+        tree._setInTree(label1, stateNode1);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(false);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000a": {
+            ".label": "0x000a",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // set second node
+        tree._setInTree(label2, stateNode2);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000": {
+            ".radix_ph": null,
+            "a": {
+              ".label": "0x000a",
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "b": {
+              ".label": "0x000b",
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+
+        // delete first node
+        tree._deleteFromTree(label1);
+
+        expect(tree._hasInTree(label1)).to.equal(false);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000b": {
+            ".label": "0x000b",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // delete second node
+        tree._deleteFromTree(label2);
+
+        expect(tree._hasInTree(label1)).to.equal(false);
+        expect(tree._hasInTree(label2)).to.equal(false);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null
+        });
+      });
+
+      it("set / delete with common label prefix - with label suffices", () => {
+        const label1 = '0x000aaa';
+        const label2 = '0x000bbb';
+
+        stateNode1._setLabel(label1);
+        stateNode2._setLabel(label2);
+
+        expect(tree._hasInTree(label1)).to.equal(false);
+        expect(tree._hasInTree(label2)).to.equal(false);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null
+        });
+
+        // set first node
+        tree._setInTree(label1, stateNode1);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(false);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000aaa": {
+            ".label": "0x000aaa",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // set second node
+        tree._setInTree(label2, stateNode2);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000": {
+            ".radix_ph": null,
+            "aaa": {
+              ".label": "0x000aaa",
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "bbb": {
+              ".label": "0x000bbb",
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+
+        // delete first node
+        tree._deleteFromTree(label1);
+
+        expect(tree._hasInTree(label1)).to.equal(false);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000bbb": {
+            ".label": "0x000bbb",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // delete second node
+        tree._deleteFromTree(label2);
+
+        expect(tree._hasInTree(label1)).to.equal(false);
+        expect(tree._hasInTree(label2)).to.equal(false);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null
+        });
+      });
+
+      it("set / delete with common label prefix - set on an internal node", () => {
+        const label1 = '0x000aaa';
+        const label2 = '0x000bbb';
+        const labelInternal = '0x000';
+
+        stateNode1._setLabel(label1);
+        stateNode2._setLabel(label2);
+        stateNodeInternal._setLabel(labelInternal);
+
+        // add terminal nodes
+        tree._setInTree(label1, stateNode1);
+        tree._setInTree(label2, stateNode2);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000": {
+            ".radix_ph": null,
+            "aaa": {
+              ".label": "0x000aaa",
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "bbb": {
+              ".label": "0x000bbb",
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+
+        // set on the internal node
+        tree._setInTree(labelInternal, stateNodeInternal);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        expect(tree._hasInTree(labelInternal)).to.equal(true);
+        expect(tree._getFromTree(labelInternal)).to.equal(stateNodeInternal);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000": {
+            ".label": "0x000",
+            ".proof_hash": null,
+            ".radix_ph": null,
+            "aaa": {
+              ".label": "0x000aaa",
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "bbb": {
+              ".label": "0x000bbb",
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+      });
+
+      it("set / delete with common label prefix - set with substring label suffix", () => {
+        const label1 = '0x000aabb';
+        const label2 = '0x000aa';
+
+        stateNode1._setLabel(label1);
+        stateNode2._setLabel(label2);
+
+        tree._setInTree(label1, stateNode1);
+        tree._setInTree(label2, stateNode2);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000aa": {
+            ".label": "0x000aa",
+            ".proof_hash": null,
+            ".radix_ph": null,
+            "bb": {
+              ".label": "0x000aabb",
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+      });
+
+      it("set / delete with common label prefix - set with superstring label suffix", () => {
+        const label1 = '0x000aa';
+        const label2 = '0x000aabb';
+
+        stateNode1._setLabel(label1);
+        stateNode2._setLabel(label2);
+
+        tree._setInTree(label1, stateNode1);
+        tree._setInTree(label2, stateNode2);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000aa": {
+            ".label": "0x000aa",
+            ".proof_hash": null,
+            ".radix_ph": null,
+            "bb": {
+              ".label": "0x000aabb",
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+      });
+
+      it("set / delete with common label prefix - set with exact-matched label suffix", () => {
+        const label = '0x000aa';
+
+        stateNode1._setLabel(label);
+        stateNode2._setLabel(label + '_');  // tweak in order to distinguish
+
+        tree._setInTree(label, stateNode1);
+        tree._setInTree(label, stateNode2);
+
+        expect(tree._hasInTree(label)).to.equal(true);
+        expect(tree._getFromTree(label)).to.equal(stateNode2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000aa": {
+            ".label": "0x000aa_",
+            ".proof_hash": null,
+            ".radix_ph": null,
+          }
+        });
+      });
+
+      it("set / delete with common label prefix - set / delete with children", () => {
+        const label1 = '0x000aaa';
+        const label2 = '0x000bbb';
+        const label21 = '0x000bbb111';
+        const label22 = '0x000bbb222';
+
+        stateNode1._setLabel(label1);
+        stateNode2._setLabel(label2);
+        stateNode21._setLabel(label21);
+        stateNode22._setLabel(label22);
+
+        // set first node
+        tree._setInTree(label1, stateNode1);
+        // set second node
+        tree._setInTree(label2, stateNode2);
+        // set children
+        tree._setInTree(label21, stateNode21);
+        tree._setInTree(label22, stateNode22);
+
+        expect(tree._hasInTree(label1)).to.equal(true);
+        expect(tree._getFromTree(label1)).to.equal(stateNode1);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        expect(tree._hasInTree(label21)).to.equal(true);
+        expect(tree._getFromTree(label21)).to.equal(stateNode21);
+        expect(tree._hasInTree(label22)).to.equal(true);
+        expect(tree._getFromTree(label22)).to.equal(stateNode22);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000": {
+            ".radix_ph": null,
+            "aaa": {
+              ".label": "0x000aaa",
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "bbb": {
+              "111": {
+                ".label": "0x000bbb111",
+                ".proof_hash": null,
+                ".radix_ph": null
+              },
+              "222": {
+                ".label": "0x000bbb222",
+                ".proof_hash": null,
+                ".radix_ph": null
+              },
+              ".label": "0x000bbb",
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+
+        // delete first node
+        tree._deleteFromTree(label1);
+
+        expect(tree._hasInTree(label1)).to.equal(false);
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        expect(tree._hasInTree(label21)).to.equal(true);
+        expect(tree._getFromTree(label21)).to.equal(stateNode21);
+        expect(tree._hasInTree(label22)).to.equal(true);
+        expect(tree._getFromTree(label22)).to.equal(stateNode22);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000bbb": {
+            "111": {
+              ".label": "0x000bbb111",
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "222": {
+              ".label": "0x000bbb222",
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            ".label": "0x000bbb",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+      });
+
+      it("set / delete with common label prefix - delete with only one child", () => {
+        const label2 = '0x000bbb';
+        const label21 = '0x000bbb111';
+
+        stateNode2._setLabel(label2);
+        stateNode21._setLabel(label21);
+
+        // set a node
+        tree._setInTree(label2, stateNode2);
+        // set a child
+        tree._setInTree(label21, stateNode21);
+
+        expect(tree._hasInTree(label2)).to.equal(true);
+        expect(tree._getFromTree(label2)).to.equal(stateNode2);
+        expect(tree._hasInTree(label21)).to.equal(true);
+        expect(tree._getFromTree(label21)).to.equal(stateNode21);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000bbb": {
+            "111": {
+              ".label": "0x000bbb111",
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            ".label": "0x000bbb",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // delete the node
+        tree._deleteFromTree(label2);
+
+        expect(tree._hasInTree(label2)).to.equal(false);
+        expect(tree._hasInTree(label21)).to.equal(true);
+        expect(tree._getFromTree(label21)).to.equal(stateNode21);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000bbb111": {
+            ".label": "0x000bbb111",
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+      });
+    });
+
+    describe("_copyTreeFrom", () => {
+      const stateNode1 = new StateNode();
+      const stateNode2 = new StateNode();
+      const stateNode21 = new StateNode();
+      const stateNode22 = new StateNode();
+
+      it("copy with children", () => {
+        const label1 = '0x000aaa';
+        const label2 = '0x000bbb';
+        const label21 = '0x000bbb111';
+        const label22 = '0x000bbb222';
+
+        stateNode1._setLabel(label1);
+        stateNode2._setLabel(label2);
+        stateNode21._setLabel(label21);
+        stateNode22._setLabel(label22);
+
+        // set state nodes
+        tree._setInTree(label1, stateNode1);
+        tree._setInTree(label2, stateNode2);
+        tree._setInTree(label21, stateNode21);
+        tree._setInTree(label22, stateNode22);
+
+        const newTree = new RadixTree();
+        newTree._copyTreeFrom(tree);
+        expect(newTree._hasInTree(label1)).to.equal(true);
+        expect(newTree._getFromTree(label1)).to.equal(stateNode1);
+        expect(newTree._hasInTree(label2)).to.equal(true);
+        expect(newTree._getFromTree(label2)).to.equal(stateNode2);
+        expect(newTree._hasInTree(label21)).to.equal(true);
+        expect(newTree._getFromTree(label21)).to.equal(stateNode21);
+        expect(newTree._hasInTree(label22)).to.equal(true);
+        expect(newTree._getFromTree(label22)).to.equal(stateNode22);
+        assert.deepEqual(newTree.toJsObject(true), {
+          ".radix_ph": null,
+          "000": {
+            ".radix_ph": null,
+            "aaa": {
+              ".label": "0x000aaa",
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "bbb": {
+              "111": {
+                ".label": "0x000bbb111",
+                ".proof_hash": null,
+                ".radix_ph": null
+              },
+              "222": {
+                ".label": "0x000bbb222",
+                ".proof_hash": null,
+                ".radix_ph": null
+              },
+              ".label": "0x000bbb",
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+      });
+    });
+  });
+
+  describe("Common APIs", () => {
+    let tree;
+
+    beforeEach(() => {
+      tree = new RadixTree();
+    })
+
+    describe("set / deletep / has / get / labels / stateNodes / size", () => {
+      const stateNode1 = new StateNode();
+      const stateNode2 = new StateNode();
+      const stateNode21 = new StateNode();
+      const stateNode22 = new StateNode();
+      const stateNodeInternal = new StateNode();
+
+      it("set with invalid state node", () => {
+        const invalidStateNode = new RadixNode();
+        const label = '0x000aaa';
+
+        expect(tree.set(label, invalidStateNode)).to.equal(false);
+        expect(tree.set(label, '')).to.equal(false);
+        expect(tree.set(label, true)).to.equal(false);
+        expect(tree.set(label, null)).to.equal(false);
+        expect(tree.set(label, undefined)).to.equal(false);
+      });
+
+      it("set / delete without common label prefix", () => {
+        const label1 = '0xa';
+        const label2 = '0xb';
+
+        expect(tree.has(label1)).to.equal(false);
+        expect(tree.has(label2)).to.equal(false);
+        assert.deepEqual(tree.labels(), []);
+        assert.deepEqual(tree.stateNodes(), []);
+        assert.deepEqual(tree.size(), 0);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null
+        });
+
+        // set first node
+        tree.set(label1, stateNode1);
+
+        expect(tree.has(label1)).to.equal(true);
+        expect(tree.get(label1)).to.equal(stateNode1);
+        expect(tree.has(label2)).to.equal(false);
+        assert.deepEqual(tree.labels(), [label1]);
+        assert.deepEqual(tree.stateNodes(), [stateNode1]);
+        assert.deepEqual(tree.size(), 1);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "a": {
+            ".label": null,
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // set second node
+        tree.set(label2, stateNode2);
+
+        expect(tree.has(label1)).to.equal(true);
+        expect(tree.get(label1)).to.equal(stateNode1);
+        expect(tree.has(label2)).to.equal(true);
+        expect(tree.get(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.labels(), [label1, label2]);
+        assert.deepEqual(tree.stateNodes(), [stateNode1, stateNode2]);
+        assert.deepEqual(tree.size(), 2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "a": {
+            ".label": null,
+            ".proof_hash": null,
+            ".radix_ph": null
+          },
+          "b": {
+            ".label": null,
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // delete first node
+        tree.delete(label1);
+
+        expect(tree.has(label1)).to.equal(false);
+        expect(tree.has(label2)).to.equal(true);
+        expect(tree.get(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.labels(), [label2]);
+        assert.deepEqual(tree.stateNodes(), [stateNode2]);
+        assert.deepEqual(tree.size(), 1);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "b": {
+            ".label": null,
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // delete second node
+        tree.delete(label2);
+
+        expect(tree.has(label1)).to.equal(false);
+        expect(tree.has(label2)).to.equal(false);
+        assert.deepEqual(tree.labels(), []);
+        assert.deepEqual(tree.stateNodes(), []);
+        assert.deepEqual(tree.size(), 0);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null
+        });
+      });
+
+      it("set / delete with common label prefix", () => {
+        const label1 = '0x000a';
+        const label2 = '0x000b';
+
+        expect(tree.has(label1)).to.equal(false);
+        expect(tree.has(label2)).to.equal(false);
+        assert.deepEqual(tree.labels(), []);
+        assert.deepEqual(tree.stateNodes(), []);
+        assert.deepEqual(tree.size(), 0);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null
+        });
+
+        // set first node
+        tree.set(label1, stateNode1);
+
+        expect(tree.has(label1)).to.equal(true);
+        expect(tree.get(label1)).to.equal(stateNode1);
+        expect(tree.has(label2)).to.equal(false);
+        assert.deepEqual(tree.labels(), [label1]);
+        assert.deepEqual(tree.stateNodes(), [stateNode1]);
+        assert.deepEqual(tree.size(), 1);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000a": {
+            ".label": null,
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // set second node
+        tree.set(label2, stateNode2);
+
+        expect(tree.has(label1)).to.equal(true);
+        expect(tree.get(label1)).to.equal(stateNode1);
+        expect(tree.has(label2)).to.equal(true);
+        expect(tree.get(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.labels(), [label1, label2]);
+        assert.deepEqual(tree.stateNodes(), [stateNode1, stateNode2]);
+        assert.deepEqual(tree.size(), 2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000": {
+            ".radix_ph": null,
+            "a": {
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "b": {
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+
+        // delete first node
+        tree.delete(label1);
+
+        expect(tree.has(label1)).to.equal(false);
+        expect(tree.has(label2)).to.equal(true);
+        expect(tree.get(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.labels(), [label2]);
+        assert.deepEqual(tree.stateNodes(), [stateNode2]);
+        assert.deepEqual(tree.size(), 1);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000b": {
+            ".label": null,
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // delete second node
+        tree.delete(label2);
+
+        expect(tree.has(label1)).to.equal(false);
+        expect(tree.has(label2)).to.equal(false);
+        assert.deepEqual(tree.labels(), []);
+        assert.deepEqual(tree.stateNodes(), []);
+        assert.deepEqual(tree.size(), 0);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null
+        });
+      });
+
+      it("set on an internal node", () => {
+        const label1 = '0x000a';
+        const label2 = '0x000b';
+        const labelInternal = '0x000';
+
+        // add terminal nodes
+        tree.set(label1, stateNode1);
+        tree.set(label2, stateNode2);
+
+        expect(tree.has(label1)).to.equal(true);
+        expect(tree.get(label1)).to.equal(stateNode1);
+        expect(tree.has(label2)).to.equal(true);
+        expect(tree.get(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.labels(), [label1, label2]);
+        assert.deepEqual(tree.stateNodes(), [stateNode1, stateNode2]);
+        assert.deepEqual(tree.size(), 2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000": {
+            ".radix_ph": null,
+            "a": {
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "b": {
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+
+        // set on the internal node
+        tree.set(labelInternal, stateNodeInternal);
+
+        expect(tree.has(label1)).to.equal(true);
+        expect(tree.get(label1)).to.equal(stateNode1);
+        expect(tree.has(label2)).to.equal(true);
+        expect(tree.get(label2)).to.equal(stateNode2);
+        expect(tree.has(labelInternal)).to.equal(true);
+        expect(tree.get(labelInternal)).to.equal(stateNodeInternal);
+        assert.deepEqual(tree.labels(), [label1, label2, labelInternal]);
+        assert.deepEqual(tree.stateNodes(), [stateNode1, stateNode2, stateNodeInternal]);
+        assert.deepEqual(tree.size(), 3);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000": {
+            ".label": null,
+            ".proof_hash": null,
+            ".radix_ph": null,
+            "a": {
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "b": {
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+      });
+
+      it("set / delete with non-empty label suffices", () => {
+        const label1 = '0x000aaa';
+        const label2 = '0x000bbb';
+
+        expect(tree.has(label1)).to.equal(false);
+        expect(tree.has(label2)).to.equal(false);
+        assert.deepEqual(tree.labels(), []);
+        assert.deepEqual(tree.stateNodes(), []);
+        assert.deepEqual(tree.size(), 0);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null
+        });
+
+        // set first node
+        tree.set(label1, stateNode1);
+
+        expect(tree.has(label1)).to.equal(true);
+        expect(tree.get(label1)).to.equal(stateNode1);
+        expect(tree.has(label2)).to.equal(false);
+        assert.deepEqual(tree.labels(), [label1]);
+        assert.deepEqual(tree.stateNodes(), [stateNode1]);
+        assert.deepEqual(tree.size(), 1);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000aaa": {
+            ".label": null,
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // set second node
+        tree.set(label2, stateNode2);
+
+        expect(tree.has(label1)).to.equal(true);
+        expect(tree.get(label1)).to.equal(stateNode1);
+        expect(tree.has(label2)).to.equal(true);
+        expect(tree.get(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.labels(), [label1, label2]);
+        assert.deepEqual(tree.stateNodes(), [stateNode1, stateNode2]);
+        assert.deepEqual(tree.size(), 2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000": {
+            ".radix_ph": null,
+            "aaa": {
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "bbb": {
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+
+        // delete first node
+        tree.delete(label1);
+
+        expect(tree.has(label1)).to.equal(false);
+        expect(tree.has(label2)).to.equal(true);
+        expect(tree.get(label2)).to.equal(stateNode2);
+        assert.deepEqual(tree.labels(), [label2]);
+        assert.deepEqual(tree.stateNodes(), [stateNode2]);
+        assert.deepEqual(tree.size(), 1);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000bbb": {
+            ".label": null,
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // delete second node
+        tree.delete(label2);
+
+        expect(tree.has(label1)).to.equal(false);
+        expect(tree.has(label2)).to.equal(false);
+        assert.deepEqual(tree.labels(), []);
+        assert.deepEqual(tree.stateNodes(), []);
+        assert.deepEqual(tree.size(), 0);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null
+        });
+      });
+
+      it("set / delete with children", () => {
+        const label1 = '0x000aaa';
+        const label2 = '0x000bbb';
+        const label21 = '0x000bbb111';
+        const label22 = '0x000bbb222';
+
+        // set first node
+        tree.set(label1, stateNode1);
+        // set second node
+        tree.set(label2, stateNode2);
+        // set children
+        tree.set(label21, stateNode21);
+        tree.set(label22, stateNode22);
+
+        expect(tree.has(label1)).to.equal(true);
+        expect(tree.get(label1)).to.equal(stateNode1);
+        expect(tree.has(label2)).to.equal(true);
+        expect(tree.get(label2)).to.equal(stateNode2);
+        expect(tree.has(label21)).to.equal(true);
+        expect(tree.get(label21)).to.equal(stateNode21);
+        expect(tree.has(label22)).to.equal(true);
+        expect(tree.get(label22)).to.equal(stateNode22);
+        assert.deepEqual(tree.labels(), [label1, label2, label21, label22]);
+        assert.deepEqual(tree.stateNodes(), [stateNode1, stateNode2, stateNode21, stateNode22]);
+        assert.deepEqual(tree.size(), 4);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000": {
+            ".radix_ph": null,
+            "aaa": {
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "bbb": {
+              "111": {
+                ".label": null,
+                ".proof_hash": null,
+                ".radix_ph": null
+              },
+              "222": {
+                ".label": null,
+                ".proof_hash": null,
+                ".radix_ph": null
+              },
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+
+        // delete first node
+        tree.delete(label1);
+
+        expect(tree.has(label1)).to.equal(false);
+        expect(tree.has(label2)).to.equal(true);
+        expect(tree.get(label2)).to.equal(stateNode2);
+        expect(tree.has(label21)).to.equal(true);
+        expect(tree.get(label21)).to.equal(stateNode21);
+        expect(tree.has(label22)).to.equal(true);
+        expect(tree.get(label22)).to.equal(stateNode22);
+        assert.deepEqual(tree.labels(), [label2, label21, label22]);
+        assert.deepEqual(tree.stateNodes(), [stateNode2, stateNode21, stateNode22]);
+        assert.deepEqual(tree.size(), 3);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000bbb": {
+            "111": {
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "222": {
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            ".label": null,
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+      });
+
+      it("delete with only one child", () => {
+        const label2 = '0x000bbb';
+        const label21 = '0x000bbb111';
+
+        // set a node
+        tree.set(label2, stateNode2);
+        // set a child
+        tree.set(label21, stateNode21);
+
+        expect(tree.has(label2)).to.equal(true);
+        expect(tree.get(label2)).to.equal(stateNode2);
+        expect(tree.has(label21)).to.equal(true);
+        expect(tree.get(label21)).to.equal(stateNode21);
+        assert.deepEqual(tree.labels(), [label2, label21]);
+        assert.deepEqual(tree.stateNodes(), [stateNode2, stateNode21]);
+        assert.deepEqual(tree.size(), 2);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000bbb": {
+            "111": {
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            ".label": null,
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+
+        // delete the node
+        tree.delete(label2);
+
+        expect(tree.has(label2)).to.equal(false);
+        expect(tree.has(label21)).to.equal(true);
+        expect(tree.get(label21)).to.equal(stateNode21);
+        assert.deepEqual(tree.labels(), [label21]);
+        assert.deepEqual(tree.stateNodes(), [stateNode21]);
+        assert.deepEqual(tree.size(), 1);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000bbb111": {
+            ".label": null,
+            ".proof_hash": null,
+            ".radix_ph": null
+          }
+        });
+      });
+
+      it("get / has / set / update / verify proof hash", () => {
+        const label1 = '0x000aaa';
+        const stateNode1 = new StateNode();
+        const stateNodePH1 = 'childStateNodePH1';
+        stateNode1.setProofHash(stateNodePH1);
+
+        const label11 = '0x000aaa111';
+        const stateNodePH11 = 'childStateNodePH11';
+        const stateNode11 = new StateNode();
+        stateNode11.setProofHash(stateNodePH11);
+
+        const label12 = '0x000aaa212';
+        const stateNodePH12 = 'childStateNodePH12';
+        const stateNode12 = new StateNode();
+        stateNode12.setProofHash(stateNodePH12);
+
+        const label21 = '0x000bbb121';
+        const stateNodePH21 = 'childStateNodePH21';
+        const stateNode21 = new StateNode();
+        stateNode21.setProofHash(stateNodePH21);
+
+        const label22 = '0x000bbb222';
+        const stateNodePH22 = 'childStateNodePH22';
+        const stateNode22 = new StateNode();
+        stateNode22.setProofHash(stateNodePH22);
+
+        const label3 = '0x111ccc';
+        const stateNode3 = new StateNode();
+        const stateNodePH3 = 'childStateNodePH3';
+        stateNode3.setProofHash(stateNodePH3);
+
+        tree.set(label1, stateNode1);
+        tree.set(label11, stateNode11);
+        tree.set(label12, stateNode12);
+        tree.set(label21, stateNode21);
+        tree.set(label22, stateNode22);
+        tree.set(label3, stateNode3);
+
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": null,
+          "000": {
+            ".radix_ph": null,
+            "aaa": {
+              "111": {
+                ".label": null,
+                ".proof_hash": "childStateNodePH11",
+                ".radix_ph": null
+              },
+              "212": {
+                ".label": null,
+                ".proof_hash": "childStateNodePH12",
+                ".radix_ph": null
+              },
+              ".label": null,
+              ".proof_hash": "childStateNodePH1",
+              ".radix_ph": null
+            },
+            "bbb": {
+              "121": {
+                ".label": null,
+                ".proof_hash": "childStateNodePH21",
+                ".radix_ph": null
+              },
+              "222": {
+                ".label": null,
+                ".proof_hash": "childStateNodePH22",
+                ".radix_ph": null
+              },
+              ".radix_ph": null
+            }
+          },
+          "111ccc": {
+            ".label": null,
+            ".proof_hash": "childStateNodePH3",
+            ".radix_ph": null
+          }
+        });
+
+        // initial status
+        expect(tree.getRootProofHash()).to.equal(null);
+        expect(tree.verifyProofHashForRadixTree()).to.equal(false);
+
+        // set
+        expect(tree.updateProofHashForRadixTree()).to.equal(9);
+        expect(tree.getRootProofHash()).to.equal(
+            '0xbc310c6c1b9d339951756d3c0f90bb25e70be0c0a261e04564917ce6c57016d5');
+        expect(tree.verifyProofHashForRadixTree()).to.equal(true);
+
+        // change of a state node's proof hash
+        stateNode21.setProofHash('another PH');
+        expect(tree.verifyProofHashForRadixTree()).to.equal(false);
+
+        // update
+        expect(tree.updateProofHashForRadixPath(label21)).to.equal(4);
+        expect(tree.getRootProofHash()).to.equal(
+            '0x20520d0c668099565300affd3c4b288fb59dc37b9fbf31702e99a37b564d12d5');
+        expect(tree.verifyProofHashForRadixTree()).to.equal(true);
+      });
+
+      it("getProofOfState", () => {
+        const label1 = '0x000aaa';
+        const stateNode1 = new StateNode();
+        const stateNodePH1 = 'childStateNodePH1';
+        stateNode1.setProofHash(stateNodePH1);
+
+        const label11 = '0x000aaa111';
+        const stateNodePH11 = 'childStateNodePH11';
+        const stateNode11 = new StateNode();
+        stateNode11.setProofHash(stateNodePH11);
+
+        const label12 = '0x000aaa212';
+        const stateNodePH12 = 'childStateNodePH12';
+        const stateNode12 = new StateNode();
+        stateNode12.setProofHash(stateNodePH12);
+
+        const label21 = '0x000bbb121';
+        const stateNodePH21 = 'childStateNodePH21';
+        const stateNode21 = new StateNode();
+        stateNode21.setProofHash(stateNodePH21);
+
+        const label22 = '0x000bbb222';
+        const stateNodePH22 = 'childStateNodePH22';
+        const stateNode22 = new StateNode();
+        stateNode22.setProofHash(stateNodePH22);
+
+        tree.set(label1, stateNode1);
+        tree.set(label11, stateNode11);
+        tree.set(label12, stateNode12);
+        tree.set(label21, stateNode21);
+        tree.set(label22, stateNode22);
+
+        expect(tree.updateProofHashForRadixTree()).to.equal(8);
+        assert.deepEqual(tree.toJsObject(true), {
+          ".radix_ph": "0x890e6c975c63529362955c359c0b7552bf1f88c4945f12a18458f8acafb17b25",
+          "000": {
+            ".radix_ph": "0x7de885f5d5ecdd9e059584874ae468ba9d1ecdebb3c320fa02e6a2ac58413386",
+            "aaa": {
+              "111": {
+                ".label": null,
+                ".proof_hash": "childStateNodePH11",
+                ".radix_ph": "0x9fb9b2e6c1dc7fed76964029cb13fb1cdc115dc0a9cef54fe052533ab992a58c"
+              },
+              "212": {
+                ".label": null,
+                ".proof_hash": "childStateNodePH12",
+                ".radix_ph": "0xbde6ad92fee46f223375703e8376c3c8d75989d3b9867520442e63e0836ff596"
+              },
+              ".label": null,
+              ".proof_hash": "childStateNodePH1",
+              ".radix_ph": "0x47f652dd768456603c8bb25c5ab7157d43e3edafc51837038f42a6026bf6bb44"
+            },
+            "bbb": {
+              "121": {
+                ".label": null,
+                ".proof_hash": "childStateNodePH21",
+                ".radix_ph": "0x68971271b6018c8827230bb696d7d2661ebb286f95851e72da889e1af6b22721"
+              },
+              "222": {
+                ".label": null,
+                ".proof_hash": "childStateNodePH22",
+                ".radix_ph": "0xba9d1dcddd02911d1d260f8acd4e3857174d98a57e6b3c7e0577c8a07056b057"
+              },
+              ".radix_ph": "0x35286cd28c53fbe623eed76d4c09246645451b92cdded41ce9952436dc4656c3"
+            }
+          }
+        });
+
+        // on an internal radix node
+        assert.deepEqual(tree.getProofOfState(label1, 'state_proof1'), {
+          ".radix_ph": "0x890e6c975c63529362955c359c0b7552bf1f88c4945f12a18458f8acafb17b25",
+          "000": {
+            ".radix_ph": "0x7de885f5d5ecdd9e059584874ae468ba9d1ecdebb3c320fa02e6a2ac58413386",
+            "aaa": {
+              ".label": "0x000aaa",
+              ".proof_hash": "state_proof1",
+              ".radix_ph": "0x47f652dd768456603c8bb25c5ab7157d43e3edafc51837038f42a6026bf6bb44"
+            },
+            "bbb": {
+              ".radix_ph": "0x35286cd28c53fbe623eed76d4c09246645451b92cdded41ce9952436dc4656c3"
+            }
+          }
+        });
+
+        // on a terminal radix node
+        assert.deepEqual(tree.getProofOfState(label22, 'state_proof22'), {
+          ".radix_ph": "0x890e6c975c63529362955c359c0b7552bf1f88c4945f12a18458f8acafb17b25",
+          "000": {
+            ".radix_ph": "0x7de885f5d5ecdd9e059584874ae468ba9d1ecdebb3c320fa02e6a2ac58413386",
+            "aaa": {
+              ".radix_ph": "0x47f652dd768456603c8bb25c5ab7157d43e3edafc51837038f42a6026bf6bb44"
+            },
+            "bbb": {
+              ".radix_ph": "0x35286cd28c53fbe623eed76d4c09246645451b92cdded41ce9952436dc4656c3",
+              "121": {
+                ".radix_ph": "0x68971271b6018c8827230bb696d7d2661ebb286f95851e72da889e1af6b22721"
+              },
+              "222": {
+                ".label": "0x000bbb222",
+                ".proof_hash": "state_proof22",
+                ".radix_ph": "0xba9d1dcddd02911d1d260f8acd4e3857174d98a57e6b3c7e0577c8a07056b057"
+              }
+            }
+          }
+        });
+      });
+    });
+
+    describe("copyFrom", () => {
+      const stateNode1 = new StateNode();
+      const stateNode2 = new StateNode();
+      const stateNode21 = new StateNode();
+      const stateNode22 = new StateNode();
+
+      it("copy with children", () => {
+        const label1 = '0x000aaa';
+        const label2 = '0x000bbb';
+        const label21 = '0x000bbb111';
+        const label22 = '0x000bbb222';
+
+        // set state nodes
+        tree.set(label1, stateNode1);
+        tree.set(label2, stateNode2);
+        tree.set(label21, stateNode21);
+        tree.set(label22, stateNode22);
+
+        const newTree = new RadixTree();
+        newTree.copyFrom(tree);
+
+        expect(newTree.has(label1)).to.equal(true);
+        expect(newTree.get(label1)).to.equal(stateNode1);
+        expect(newTree.has(label2)).to.equal(true);
+        expect(newTree.get(label2)).to.equal(stateNode2);
+        expect(newTree.has(label21)).to.equal(true);
+        expect(newTree.get(label21)).to.equal(stateNode21);
+        expect(newTree.has(label22)).to.equal(true);
+        expect(newTree.get(label22)).to.equal(stateNode22);
+        assert.deepEqual(newTree.labels(), [label1, label2, label21, label22]);
+        assert.deepEqual(newTree.stateNodes(), [stateNode1, stateNode2, stateNode21, stateNode22]);
+        assert.deepEqual(newTree.size(), 4);
+        assert.deepEqual(newTree.toJsObject(true), {
+          ".radix_ph": null,
+          "000": {
+            ".radix_ph": null,
+            "aaa": {
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            },
+            "bbb": {
+              "111": {
+                ".label": null,
+                ".proof_hash": null,
+                ".radix_ph": null
+              },
+              "222": {
+                ".label": null,
+                ".proof_hash": null,
+                ".radix_ph": null
+              },
+              ".label": null,
+              ".proof_hash": null,
+              ".radix_ph": null
+            }
+          }
+        });
+      });
+    });
+  });
+});
diff --git a/unittest/rule-util.test.js b/unittest/rule-util.test.js
index 0c737e99d..6d66c5de6 100644
--- a/unittest/rule-util.test.js
+++ b/unittest/rule-util.test.js
@@ -171,6 +171,62 @@ describe("RuleUtil", () => {
     })
   })
 
+  describe("isHexString", () => {
+    it("when invalid input", () => {
+      expect(util.isHexString(true)).to.equal(false);
+      expect(util.isHexString(false)).to.equal(false);
+      expect(util.isHexString(0)).to.equal(false);
+      expect(util.isHexString(10)).to.equal(false);
+      expect(util.isHexString(null)).to.equal(false);
+      expect(util.isHexString(undefined)).to.equal(false);
+      expect(util.isHexString(Infinity)).to.equal(false);
+      expect(util.isHexString(NaN)).to.equal(false);
+      expect(util.isHexString('')).to.equal(false);
+      expect(util.isHexString('abc')).to.equal(false);
+      expect(util.isHexString('0')).to.equal(false);
+      expect(util.isHexString([10])).to.equal(false);
+      expect(util.isHexString({a: 'A'})).to.equal(false);
+      expect(util.isHexString('0x6af1ec8d4fx')).to.equal(false);
+      expect(util.isHexString('0x6AF1EC8D4FX')).to.equal(false);
+      expect(util.isHexString('0xx6af1ec8d4f')).to.equal(false);
+      expect(util.isHexString('0xx6AF1EC8D4F')).to.equal(false);
+      expect(util.isHexString('00x6af1ec8d4f')).to.equal(false);
+      expect(util.isHexString('00x6AF1EC8D4F')).to.equal(false);
+    })
+
+    it("when valid input", () => {
+      expect(util.isHexString('0x')).to.equal(true);
+      expect(util.isHexString('0x6af1ec8d4f')).to.equal(true);
+      expect(util.isHexString('0x6AF1EC8D4F')).to.equal(true);
+    })
+  })
+
+  describe("isValidHash", () => {
+    it("when invalid input", () => {
+      expect(util.isValidHash(true)).to.equal(false);
+      expect(util.isValidHash(false)).to.equal(false);
+      expect(util.isValidHash(0)).to.equal(false);
+      expect(util.isValidHash(10)).to.equal(false);
+      expect(util.isValidHash(null)).to.equal(false);
+      expect(util.isValidHash(undefined)).to.equal(false);
+      expect(util.isValidHash(Infinity)).to.equal(false);
+      expect(util.isValidHash(NaN)).to.equal(false);
+      expect(util.isValidHash('')).to.equal(false);
+      expect(util.isValidHash('abc')).to.equal(false);
+      expect(util.isValidHash('0')).to.equal(false);
+      expect(util.isValidHash([10])).to.equal(false);
+      expect(util.isValidHash({a: 'A'})).to.equal(false);
+      expect(util.isValidHash('0x')).to.equal(false);
+      expect(util.isValidHash('0x6af1ec8d4f0a55bac328cb20336ed0eff46fa6334ebd112147892f1b15aafc8')).to.equal(false); // 63 chars
+      expect(util.isValidHash('0x6af1ec8d4f0a55bac328cb20336ed0eff46fa6334ebd112147892f1b15aafc8cc')).to.equal(false); // 65 chars
+    })
+
+    it("when valid input", () => {
+      expect(util.isValidHash('0x6af1ec8d4f0a55bac328cb20336ed0eff46fa6334ebd112147892f1b15aafc8c')).to.equal(true);
+      expect(util.isValidHash('0x89a1b02058f0d0b7c93957d0ff290cf44cef419d1275afcb430f6e9536e4afb5')).to.equal(true);
+    })
+  })
+
   describe("keys", () => {
     it("when invalid input", () => {
       assert.deepEqual(util.keys(true), []);
@@ -274,32 +330,6 @@ describe("RuleUtil", () => {
     })
   })
 
-  describe("toBool", () => {
-    it("returns false", () => {
-      expect(util.toBool(0)).to.equal(false);
-      expect(util.toBool(10)).to.equal(false);
-      expect(util.toBool(-1)).to.equal(false);
-      expect(util.toBool(15.5)).to.equal(false);
-      expect(util.toBool(null)).to.equal(false);
-      expect(util.toBool(undefined)).to.equal(false);
-      expect(util.toBool(Infinity)).to.equal(false);
-      expect(util.toBool(NaN)).to.equal(false);
-      expect(util.toBool('')).to.equal(false);
-      expect(util.toBool('abc')).to.equal(false);
-      expect(util.toBool('false')).to.equal(false);
-      expect(util.toBool({})).to.equal(false);
-      expect(util.toBool({a: 'A'})).to.equal(false);
-      expect(util.toBool([])).to.equal(false);
-      expect(util.toBool([10])).to.equal(false);
-      expect(util.toBool(false)).to.equal(false);
-    })
-
-    it("returns true", () => {
-      expect(util.toBool(true)).to.equal(true);
-      expect(util.toBool('true')).to.equal(true);
-    })
-  })
-
   describe("isValAddr", () => {
     it("when non-string input", () => {
       expect(util.isValAddr(true)).to.equal(false);
@@ -386,4 +416,30 @@ describe("RuleUtil", () => {
           'staking|consensus|0x09A0d53FDf1c36A131938eb379b98910e55EEfe1|0')).to.equal(true);
     })
   })
+
+  describe("toBool", () => {
+    it("returns false", () => {
+      expect(util.toBool(0)).to.equal(false);
+      expect(util.toBool(10)).to.equal(false);
+      expect(util.toBool(-1)).to.equal(false);
+      expect(util.toBool(15.5)).to.equal(false);
+      expect(util.toBool(null)).to.equal(false);
+      expect(util.toBool(undefined)).to.equal(false);
+      expect(util.toBool(Infinity)).to.equal(false);
+      expect(util.toBool(NaN)).to.equal(false);
+      expect(util.toBool('')).to.equal(false);
+      expect(util.toBool('abc')).to.equal(false);
+      expect(util.toBool('false')).to.equal(false);
+      expect(util.toBool({})).to.equal(false);
+      expect(util.toBool({a: 'A'})).to.equal(false);
+      expect(util.toBool([])).to.equal(false);
+      expect(util.toBool([10])).to.equal(false);
+      expect(util.toBool(false)).to.equal(false);
+    })
+
+    it("returns true", () => {
+      expect(util.toBool(true)).to.equal(true);
+      expect(util.toBool('true')).to.equal(true);
+    })
+  })
 })
\ No newline at end of file
diff --git a/unittest/state-node.test.js b/unittest/state-node.test.js
index 8c8525031..01f69f345 100644
--- a/unittest/state-node.test.js
+++ b/unittest/state-node.test.js
@@ -4,8 +4,11 @@ const expect = chai.expect;
 const assert = chai.assert;
 
 const CommonUtil = require('../common/common-util');
-const { HASH_DELIMITER } = require('../common/constants');
 const { GET_OPTIONS_INCLUDE_ALL } = require('./test-util');
+const {
+  updateStateInfoForStateTree,
+  verifyProofHashForStateTree,
+} = require('../db/state-util');
 
 describe("state-node", () => {
   let node;
@@ -13,9 +16,11 @@ describe("state-node", () => {
   let child1;
   let child2;
   let child3;
-  const label1 = 'label1';
-  const label2 = 'label2';
-  const label3 = 'label3';
+  let child4;
+  const label1 = '0x00aaaa';
+  const label2 = '0x11bbbb';
+  const label3 = '0x11bb00';
+  const label4 = '0x11bb11';
   let stateTree;
 
   beforeEach(() => {
@@ -24,22 +29,27 @@ describe("state-node", () => {
     child1 = new StateNode();
     child2 = new StateNode();
     child3 = new StateNode();
+    child4 = new StateNode();
     child1.setValue('value1');
     child2.setValue('value2');
     child3.setValue('value3');
+    child4.setValue('value4');
     stateTree = new StateNode();
     stateTree.setChild(label1, child1);
     stateTree.setChild(label2, child2);
     stateTree.setChild(label3, child3);
+    stateTree.setChild(label4, child4);
   })
 
   describe("Initialization", () => {
     it("constructor", () => {
+      expect(node.label).to.equal(null);
       expect(node.isLeaf).to.equal(true);
       assert.deepEqual(node.getParentNodes(), []);
       expect(node.numParents()).to.equal(0);
       assert.deepEqual(node.getChildLabels(), []);
       assert.deepEqual(node.getChildNodes(), []);
+      expect(node.label).to.equal(null);
       expect(node.value).to.equal(null);
       expect(node.proofHash).to.equal(null);
       expect(node.version).to.equal(null);
@@ -50,6 +60,7 @@ describe("state-node", () => {
     it("constructor", () => {
       const node2 = new StateNode('version1');
       expect(node2.version).to.equal('version1');
+      expect(node2.label).to.equal(null);
       expect(node2.isLeaf).to.equal(true);
       expect(node2.parentSet).to.not.be.null;
       expect(node2.childMap).to.not.be.null;
@@ -67,6 +78,7 @@ describe("state-node", () => {
 
   describe("clone", () => {
     it("leaf node", () => {
+      node._setLabel('label');
       node.setValue('value0');
       node.setProofHash('hash');
       node.setVersion('version1');
@@ -77,6 +89,8 @@ describe("state-node", () => {
       assert.deepEqual(clone.getParentNodes(), []);
       assert.deepEqual(clone.getChildLabels(), []);
       assert.deepEqual(clone.getChildNodes(), []);
+      assert.deepEqual(clone.numChildren(), 0);
+      expect(clone.getLabel()).to.equal('label');
       expect(clone.getValue()).to.equal('value0');
       expect(clone.getProofHash()).to.equal('hash');
       expect(clone.getTreeHeight()).to.equal(node.getTreeHeight());
@@ -87,12 +101,16 @@ describe("state-node", () => {
     });
 
     it("internal node", () => {
-      stateTree.setProofHash('hash');
+      stateTree._setLabel('label_root');
       stateTree.setVersion('version1');
       assert.deepEqual(stateTree.getParentNodes(), []);
       assert.deepEqual(child1.getParentNodes(), [stateTree]);
       assert.deepEqual(child2.getParentNodes(), [stateTree]);
       assert.deepEqual(child3.getParentNodes(), [stateTree]);
+      assert.deepEqual(child4.getParentNodes(), [stateTree]);
+      expect(verifyProofHashForStateTree(stateTree)).to.equal(false);
+      updateStateInfoForStateTree(stateTree);
+      expect(verifyProofHashForStateTree(stateTree)).to.equal(true);
 
       const clone = stateTree.clone();
       expect(clone.getVersion()).to.equal(stateTree.getVersion());
@@ -100,11 +118,15 @@ describe("state-node", () => {
       assert.deepEqual(child1.getParentNodes(), [stateTree, clone]);
       assert.deepEqual(child2.getParentNodes(), [stateTree, clone]);
       assert.deepEqual(child3.getParentNodes(), [stateTree, clone]);
+      assert.deepEqual(child4.getParentNodes(), [stateTree, clone]);
       assert.deepEqual(clone.getParentNodes(), []);
       assert.deepEqual(clone.getChildLabels(), stateTree.getChildLabels());
       assert.deepEqual(clone.getChildNodes(), stateTree.getChildNodes());
+      assert.deepEqual(clone.numChildren(), stateTree.numChildren());
+      // Proof hash is verified without updateStateInfoForStateTree() call!
+      expect(verifyProofHashForStateTree(clone)).to.equal(true);
+      expect(clone.getLabel()).to.equal('label_root');
       expect(clone.getValue()).to.equal(null);
-      expect(clone.getProofHash()).to.equal('hash');
       expect(clone.getTreeHeight()).to.equal(stateTree.getTreeHeight());
       expect(clone.getTreeSize()).to.equal(stateTree.getTreeSize());
       expect(clone.getTreeBytes()).to.equal(stateTree.getTreeBytes());
@@ -187,18 +209,18 @@ describe("state-node", () => {
       node2.setValue('value');
       expect(node1.equal(node2)).to.equal(true);
 
-      node1._addParent(parent);
+      node1.addParent(parent);
       expect(node1.equal(node2)).to.equal(false);
-      node2._addParent(parent);
+      node2.addParent(parent);
       expect(node1.equal(node2)).to.equal(true);
     });
 
     it("internal", () => {
       expect(node1.equal(node2)).to.equal(true);
 
-      node1._addParent(parent);
+      node1.addParent(parent);
       expect(node1.equal(node2)).to.equal(false);
-      node2._addParent(parent);
+      node2.addParent(parent);
       expect(node1.equal(node2)).to.equal(true);
 
       node1.setChild(label1, child1);
@@ -595,6 +617,17 @@ describe("state-node", () => {
 
   })
 
+  describe("label", () => {
+    it("get / has / set / reset", () => {
+      expect(node.hasLabel()).to.equal(false);
+      node._setLabel('label');
+      expect(node.hasLabel()).to.equal(true);
+      expect(node.getLabel()).to.equal('label');
+      node._resetLabel();
+      expect(node.hasLabel()).to.equal(false);
+    });
+  });
+
   describe("isLeaf", () => {
     it("get / set", () => {
       expect(node.getIsLeaf()).to.equal(true);
@@ -632,13 +665,13 @@ describe("state-node", () => {
       assert.deepEqual(child.getParentNodes(), []);
       expect(child.numParents()).to.equal(0);
 
-      child._addParent(parent1);
+      child.addParent(parent1);
       expect(child._hasParent(parent1)).to.equal(true);
       expect(child._hasParent(parent2)).to.equal(false);
       assert.deepEqual(child.getParentNodes(), [parent1]);
       expect(child.numParents()).to.equal(1);
 
-      child._addParent(parent2);
+      child.addParent(parent2);
       expect(child._hasParent(parent1)).to.equal(true);
       expect(child._hasParent(parent2)).to.equal(true);
       assert.deepEqual(child.getParentNodes(), [parent1, parent2]);
@@ -673,8 +706,8 @@ describe("state-node", () => {
       expect(child1.numParents()).to.equal(0);
       expect(child2.numParents()).to.equal(0);
 
-      child1._addParent(parent1);
-      child2._addParent(parent2);
+      child1.addParent(parent1);
+      child2.addParent(parent2);
       expect(child1._hasParent(parent1)).to.equal(true);
       expect(child1._hasParent(parent2)).to.equal(false);
       expect(child2._hasParent(parent1)).to.equal(false);
@@ -684,8 +717,8 @@ describe("state-node", () => {
       expect(child1.numParents()).to.equal(1);
       expect(child2.numParents()).to.equal(1);
 
-      child1._addParent(parent2);
-      child2._addParent(parent1);
+      child1.addParent(parent2);
+      child2.addParent(parent1);
       expect(child1._hasParent(parent1)).to.equal(true);
       expect(child1._hasParent(parent2)).to.equal(true);
       expect(child2._hasParent(parent1)).to.equal(true);
@@ -726,12 +759,12 @@ describe("state-node", () => {
       assert.deepEqual(child.getParentNodes(), []);
       expect(child.numParents()).to.equal(0);
 
-      child._addParent(parent);
+      child.addParent(parent);
       expect(child._hasParent(parent)).to.equal(true);
       assert.deepEqual(child.getParentNodes(), [parent]);
       expect(child.numParents()).to.equal(1);
 
-      child._addParent(parent);
+      child.addParent(parent);
       expect(child._hasParent(parent)).to.equal(true);
       assert.deepEqual(child.getParentNodes(), [parent]);
       expect(child.numParents()).to.equal(1);
@@ -747,7 +780,7 @@ describe("state-node", () => {
       assert.deepEqual(child.getParentNodes(), []);
       expect(child.numParents()).to.equal(0);
 
-      child._addParent(parent1);
+      child.addParent(parent1);
       expect(child._hasParent(parent1)).to.equal(true);
       expect(child._hasParent(parent2)).to.equal(false);
       assert.deepEqual(child.getParentNodes(), [parent1]);
@@ -778,6 +811,8 @@ describe("state-node", () => {
       assert.deepEqual(child2.getParentNodes(), []);
       expect(child1.numParents()).to.equal(0);
       expect(child2.numParents()).to.equal(0);
+      expect(child1.hasLabel()).to.equal(false);
+      expect(child2.hasLabel()).to.equal(false);
       expect(parent.getIsLeaf()).to.equal(true);
 
       parent.setChild(label1, child1);
@@ -789,6 +824,9 @@ describe("state-node", () => {
       assert.deepEqual(child2.getParentNodes(), []);
       expect(child1.numParents()).to.equal(1);
       expect(child2.numParents()).to.equal(0);
+      expect(child1.hasLabel()).to.equal(true);
+      expect(child1.getLabel()).to.equal(label1);
+      expect(child2.hasLabel()).to.equal(false);
       expect(parent.getIsLeaf()).to.equal(false);
 
       parent.setChild(label2, child2);
@@ -800,6 +838,10 @@ describe("state-node", () => {
       assert.deepEqual(child2.getParentNodes(), [parent]);
       expect(child1.numParents()).to.equal(1);
       expect(child2.numParents()).to.equal(1);
+      expect(child1.hasLabel()).to.equal(true);
+      expect(child1.getLabel()).to.equal(label1);
+      expect(child2.hasLabel()).to.equal(true);
+      expect(child2.getLabel()).to.equal(label2);
       expect(parent.getIsLeaf()).to.equal(false);
 
       parent.deleteChild(label1);
@@ -811,6 +853,9 @@ describe("state-node", () => {
       assert.deepEqual(child2.getParentNodes(), [parent]);
       expect(child1.numParents()).to.equal(0);
       expect(child2.numParents()).to.equal(1);
+      expect(child1.hasLabel()).to.equal(true);
+      expect(child2.hasLabel()).to.equal(true);
+      expect(child2.getLabel()).to.equal(label2);
       expect(parent.getIsLeaf()).to.equal(false);
 
       parent.deleteChild(label2);
@@ -822,6 +867,8 @@ describe("state-node", () => {
       assert.deepEqual(child2.getParentNodes(), []);
       expect(child1.numParents()).to.equal(0);
       expect(child2.numParents()).to.equal(0);
+      expect(child1.hasLabel()).to.equal(true);
+      expect(child2.hasLabel()).to.equal(true);
       expect(parent.getIsLeaf()).to.equal(true);
     });
 
@@ -846,6 +893,8 @@ describe("state-node", () => {
       assert.deepEqual(child2.getParentNodes(), []);
       expect(child1.numParents()).to.equal(0);
       expect(child2.numParents()).to.equal(0);
+      expect(child1.hasLabel()).to.equal(false);
+      expect(child2.hasLabel()).to.equal(false);
       expect(parent1.getIsLeaf()).to.equal(true);
       expect(parent2.getIsLeaf()).to.equal(true);
 
@@ -863,6 +912,10 @@ describe("state-node", () => {
       assert.deepEqual(child2.getParentNodes(), [parent2]);
       expect(child1.numParents()).to.equal(1);
       expect(child2.numParents()).to.equal(1);
+      expect(child1.hasLabel()).to.equal(true);
+      expect(child1.getLabel()).to.equal(label1);
+      expect(child2.hasLabel()).to.equal(true);
+      expect(child2.getLabel()).to.equal(label2);
       expect(parent1.getIsLeaf()).to.equal(false);
       expect(parent2.getIsLeaf()).to.equal(false);
 
@@ -880,11 +933,15 @@ describe("state-node", () => {
       assert.deepEqual(child2.getParentNodes(), [parent2, parent1]);
       expect(child1.numParents()).to.equal(2);
       expect(child2.numParents()).to.equal(2);
+      expect(child1.hasLabel()).to.equal(true);
+      expect(child1.getLabel()).to.equal(label1);
+      expect(child2.hasLabel()).to.equal(true);
+      expect(child2.getLabel()).to.equal(label2);
       expect(parent1.getIsLeaf()).to.equal(false);
       expect(parent2.getIsLeaf()).to.equal(false);
 
-      parent1.deleteChild(label1, child1);
-      parent2.deleteChild(label2, child2);
+      parent1.deleteChild(label1);
+      parent2.deleteChild(label2);
       expect(parent1.hasChild(label1)).to.equal(false);
       expect(parent1.hasChild(label2)).to.equal(true);
       expect(parent2.hasChild(label1)).to.equal(true);
@@ -897,11 +954,15 @@ describe("state-node", () => {
       assert.deepEqual(child2.getParentNodes(), [parent1]);
       expect(child1.numParents()).to.equal(1);
       expect(child2.numParents()).to.equal(1);
+      expect(child1.hasLabel()).to.equal(true);
+      expect(child1.getLabel()).to.equal(label1);
+      expect(child2.hasLabel()).to.equal(true);
+      expect(child2.getLabel()).to.equal(label2);
       expect(parent1.getIsLeaf()).to.equal(false);
       expect(parent2.getIsLeaf()).to.equal(false);
 
-      parent1.deleteChild(label2, child2);
-      parent2.deleteChild(label1, child1);
+      parent1.deleteChild(label2);
+      parent2.deleteChild(label1);
       expect(parent1.hasChild(label1)).to.equal(false);
       expect(parent1.hasChild(label2)).to.equal(false);
       expect(parent2.hasChild(label1)).to.equal(false);
@@ -914,6 +975,8 @@ describe("state-node", () => {
       assert.deepEqual(child2.getParentNodes(), []);
       expect(child1.numParents()).to.equal(0);
       expect(child2.numParents()).to.equal(0);
+      expect(child1.hasLabel()).to.equal(true);
+      expect(child2.hasLabel()).to.equal(true);
       expect(parent1.getIsLeaf()).to.equal(true);
       expect(parent2.getIsLeaf()).to.equal(true);
     });
@@ -1120,12 +1183,23 @@ describe("state-node", () => {
       child1.setProofHash('proofHash1');
       child2.setProofHash('proofHash2');
       child3.setProofHash('proofHash3');
-      const preimage =
-          `${label1}${HASH_DELIMITER}${child1.getProofHash()}${HASH_DELIMITER}` +
-          `${label2}${HASH_DELIMITER}${child2.getProofHash()}${HASH_DELIMITER}` +
-          `${label3}${HASH_DELIMITER}${child3.getProofHash()}`;
-      expect(stateTree.buildProofHash()).to.equal(
-          CommonUtil.hashString(CommonUtil.toString(preimage)));
+      child4.setProofHash('proofHash4');
+      expect(stateTree.radixTree.verifyProofHashForRadixTree()).to.equal(false);
+
+      // build proof hash without updatedChildLabel
+      const proofHash = stateTree.buildProofHash();
+      expect(proofHash).to.equal(stateTree.radixTree.getRootProofHash());
+      expect(stateTree.radixTree.verifyProofHashForRadixTree()).to.equal(true);
+
+      // set another proof hash value for a child
+      child2.setProofHash('another PH');
+      expect(stateTree.radixTree.verifyProofHashForRadixTree()).to.equal(false);
+
+      // build proof hash with updatedChildLabel
+      const newProofHash = stateTree.buildProofHash(label2);
+      expect(newProofHash).not.equal(proofHash);  // Updated
+      expect(newProofHash).to.equal(stateTree.radixTree.getRootProofHash());
+      expect(stateTree.radixTree.verifyProofHashForRadixTree()).to.equal(true);
     });
   });
 
@@ -1151,7 +1225,8 @@ describe("state-node", () => {
       child1.setTreeHeight(0);
       child2.setTreeHeight(1);
       child3.setTreeHeight(2);
-      expect(stateTree.computeTreeHeight()).to.equal(3);
+      child4.setTreeHeight(3);
+      expect(stateTree.computeTreeHeight()).to.equal(4);
     });
   });
 
@@ -1174,10 +1249,11 @@ describe("state-node", () => {
     });
 
     it("internal node", () => {
-      child1.setTreeSize(2);
-      child2.setTreeSize(3);
-      child3.setTreeSize(5);
-      expect(stateTree.computeTreeSize()).to.equal(11);
+      child1.setTreeSize(10);
+      child2.setTreeSize(20);
+      child3.setTreeSize(30);
+      child4.setTreeSize(40);
+      expect(stateTree.computeTreeSize()).to.equal(101);
     });
   });
 
@@ -1186,14 +1262,14 @@ describe("state-node", () => {
       const parent = new StateNode();
       parent.setChild('child', node);
 
-      // node.parentSet : ref set (1 * 8 = 8 bytes)
       node.setVersion('ver');  // string (3 * 2 = 6 bytes)
       // node.isLeaf : boolean (4 bytses)
       node.setProofHash('hash');  // string (4 * 2 = 8 bytses)
       // node.treeHeight : number (8 bytses)
       // node.treeSize : number (8 bytses)
       // node.treeBytes : number (8 bytes)
-      // TOTAL: 50 - 6 = 44 bytes (exclude version)
+      // TOTAL: 42 - 6 = 36 bytes (exclude version)
+      expect(node.computeNodeBytes()).to.equal(36);
 
       node.setValue(true);  // boolean (4 bytes)
       expect(node.computeTreeBytes()).to.equal(40);
@@ -1215,59 +1291,80 @@ describe("state-node", () => {
       const parent = new StateNode();
       parent.setChild('child', stateTree);
 
-      // stateTree.parentSet : ref set (1 * 8 = 8 bytes)
-      // stateTree.childMap : ref map (3 * 8 = 24 bytes)
       stateTree.setVersion('ver');  // string (3 * 2 = 6 bytes)
       // stateTree.isLeaf : boolean (4 bytses)
+      // stateTree.value : null (0 bytses)
       stateTree.setProofHash('hash');  // string (4 * 2 = 8 bytses)
       // stateTree.treeHeight : number (8 bytses)
       // stateTree.treeSize : number (8 bytses)
       // stateTree.treeBytes : number (8 bytes)
-      // TOTAL: 74 - 6 = 68 bytes (exclude version)
+      // TOTAL: 42 - 6 = 36 bytes (exclude version)
+      expect(stateTree.computeNodeBytes()).to.equal(36);
 
       child1.setTreeBytes(10);
       child2.setTreeBytes(20);
       child3.setTreeBytes(30);
-      // 68 + 6('label1') * 2 + 10 + 6('label2') * 2 + 20 + 6('label3') * 2 + 30 = 164
-      expect(stateTree.computeTreeBytes()).to.equal(132);
+      child4.setTreeBytes(40);
+      // 36 + 8(label1) * 2 + 10 + 8(label2) * 2 + 20 + 8(label3) * 2 + 30 + 8(label4) * 2 + 40 = 200
+      expect(stateTree.computeTreeBytes()).to.equal(200);
     });
   });
 
-  describe("updateProofHashAndStateInfo", () => {
+  describe("updateStateInfo / verifyProofHash", () => {
     it("leaf node", () => {
       node.setValue(true);
-      node.updateProofHashAndStateInfo();
+      expect(node.verifyProofHash()).to.equal(false);
+      node.updateStateInfo();
       expect(node.getProofHash()).to.equal(node.buildProofHash());
+      expect(node.verifyProofHash()).to.equal(true);
       expect(node.getTreeHeight()).to.equal(node.computeTreeHeight());
       expect(node.getTreeSize()).to.equal(node.computeTreeSize());
+
       node.setValue(10);
-      node.updateProofHashAndStateInfo();
+      expect(node.verifyProofHash()).to.equal(false);
+      node.updateStateInfo();
       expect(node.getProofHash()).to.equal(node.buildProofHash());
+      expect(node.verifyProofHash()).to.equal(true);
       expect(node.getTreeHeight()).to.equal(node.computeTreeHeight());
       expect(node.getTreeSize()).to.equal(node.computeTreeSize());
+
       node.setValue(-200);
-      node.updateProofHashAndStateInfo();
+      expect(node.verifyProofHash()).to.equal(false);
+      node.updateStateInfo();
       expect(node.getProofHash()).to.equal(node.buildProofHash());
+      expect(node.verifyProofHash()).to.equal(true);
       expect(node.getTreeHeight()).to.equal(node.computeTreeHeight());
       expect(node.getTreeSize()).to.equal(node.computeTreeSize());
+
       node.setValue('');
-      node.updateProofHashAndStateInfo();
+      expect(node.verifyProofHash()).to.equal(false);
+      node.updateStateInfo();
       expect(node.getProofHash()).to.equal(node.buildProofHash());
+      expect(node.verifyProofHash()).to.equal(true);
       expect(node.getTreeHeight()).to.equal(node.computeTreeHeight());
       expect(node.getTreeSize()).to.equal(node.computeTreeSize());
-      node.setValue('unittest');
-      node.updateProofHashAndStateInfo();
+
+      node.setValue('str');
+      expect(node.verifyProofHash()).to.equal(false);
+      node.updateStateInfo();
       expect(node.getProofHash()).to.equal(node.buildProofHash());
+      expect(node.verifyProofHash()).to.equal(true);
       expect(node.getTreeHeight()).to.equal(node.computeTreeHeight());
       expect(node.getTreeSize()).to.equal(node.computeTreeSize());
+
       node.setValue(null);
-      node.updateProofHashAndStateInfo();
+      expect(node.verifyProofHash()).to.equal(false);
+      node.updateStateInfo();
       expect(node.getProofHash()).to.equal(node.buildProofHash());
+      expect(node.verifyProofHash()).to.equal(true);
       expect(node.getTreeHeight()).to.equal(node.computeTreeHeight());
       expect(node.getTreeSize()).to.equal(node.computeTreeSize());
+
       node.setValue(undefined);
-      node.updateProofHashAndStateInfo();
+      expect(node.verifyProofHash()).to.equal(false);
+      node.updateStateInfo();
       expect(node.getProofHash()).to.equal(node.buildProofHash());
+      expect(node.verifyProofHash()).to.equal(true);
       expect(node.getTreeHeight()).to.equal(node.computeTreeHeight());
       expect(node.getTreeSize()).to.equal(node.computeTreeSize());
     });
@@ -1276,16 +1373,118 @@ describe("state-node", () => {
       child1.setProofHash('proofHash1');
       child2.setProofHash('proofHash2');
       child3.setProofHash('proofHash3');
+      child4.setProofHash('proofHash4');
       child1.setTreeHeight(1);
       child2.setTreeHeight(2);
       child3.setTreeHeight(3);
-      child1.setTreeSize(2);
-      child2.setTreeSize(3);
-      child3.setTreeSize(5);
-      node.updateProofHashAndStateInfo();
-      expect(node.getProofHash()).to.equal(node.buildProofHash());
-      expect(node.getTreeHeight()).to.equal(node.computeTreeHeight());
-      expect(node.getTreeSize()).to.equal(node.computeTreeSize());
+      child4.setTreeHeight(4);
+      child1.setTreeSize(10);
+      child2.setTreeSize(20);
+      child3.setTreeSize(30);
+      child4.setTreeSize(40);
+      expect(stateTree.verifyProofHash()).to.equal(false);
+
+      // update without updatedChildLabel
+      stateTree.updateStateInfo();
+      const proofHash = stateTree.getProofHash();
+      expect(proofHash).to.equal(stateTree.buildProofHash());
+      expect(stateTree.verifyProofHash()).to.equal(true);
+      expect(stateTree.getTreeHeight()).to.equal(stateTree.computeTreeHeight());
+      expect(stateTree.getTreeSize()).to.equal(stateTree.computeTreeSize());
+      expect(stateTree.getTreeBytes()).to.equal(stateTree.computeTreeBytes());
+
+      // set another proof hash value for a child
+      child2.setProofHash('another PH');
+      expect(stateTree.verifyProofHash()).to.equal(false);
+
+      // update with updatedChildLabel
+      stateTree.updateStateInfo(label2);
+      const newProofHash = stateTree.getProofHash();
+      expect(newProofHash).not.equal(proofHash);  // Updated
+      expect(newProofHash).to.equal(stateTree.buildProofHash());
+      expect(stateTree.verifyProofHash()).to.equal(true);
+    });
+
+    it("verifyProofHash with updatedChildLabel", () => {
+      child1.setProofHash('proofHash1');
+      child2.setProofHash('proofHash2');
+      child3.setProofHash('proofHash3');
+      child4.setProofHash('proofHash4');
+      expect(stateTree.verifyProofHash(label2)).to.equal(false);
+
+      // update with updatedChildLabel
+      stateTree.updateStateInfo(label2);
+      // verify with updatedChildLabel
+      expect(stateTree.verifyProofHash(label2)).to.equal(true);
+      // verify without updatedChildLabel
+      expect(stateTree.verifyProofHash()).to.equal(false);
+    });
+  });
+
+  describe("getProofOfState", () => {
+    it("leaf node", () => {
+      node.setValue(true);  // leaf node
+      node.setProofHash('proofHash');
+      assert.deepEqual(node.getProofOfState(), {
+        ".proof_hash": "proofHash"
+      });
+    });
+
+    it("internal node", () => {
+      child1.setProofHash('proofHash1');
+      child2.setProofHash('proofHash2');
+      child3.setProofHash('proofHash3');
+      child4.setProofHash('proofHash4');
+      stateTree.setProofHash('proofHash');
+
+      stateTree.updateStateInfo();
+      assert.deepEqual(stateTree.radixTree.toJsObject(true), {
+        ".radix_ph": "0xd9251f484361885000e88f2385777e1c4558a08125199a99c6b3296b459628c6",
+        "00aaaa": {
+          ".label": "0x00aaaa",
+          ".proof_hash": "proofHash1",
+          ".radix_ph": "0xd8895ab36f227519e479a4bf7cfcbf963deb8e69e8172f395af8db83172bf22c"
+        },
+        "11bb": {
+          "11": {
+            ".label": "0x11bb11",
+            ".proof_hash": "proofHash4",
+            ".radix_ph": "0x741ba4788b06907f8c99c60a6f483f885cc1b4fb27f9e1bed71dfd1d8a213214"
+          },
+          ".radix_ph": "0x099ad81295e3257147362606afc34b47757dd5c1508d441e248302be8577ed44",
+          "00": {
+            ".label": "0x11bb00",
+            ".proof_hash": "proofHash3",
+            ".radix_ph": "0x3dfb52c0d974feb0559c9efafa996fb286717785e98871336e68ffb52d04bdf4"
+          },
+          "bb": {
+            ".label": "0x11bbbb",
+            ".proof_hash": "proofHash2",
+            ".radix_ph": "0xbbc5610ad726c88350abbe6513ab8f7441cbe8ff09ece86642a827feb53ce184"
+          }
+        }
+      });
+
+      assert.deepEqual(stateTree.getProofOfState(label2, 'childProof2'), {
+        ".radix_ph": "0xd9251f484361885000e88f2385777e1c4558a08125199a99c6b3296b459628c6",
+        "00aaaa": {
+          ".radix_ph": "0xd8895ab36f227519e479a4bf7cfcbf963deb8e69e8172f395af8db83172bf22c"
+        },
+        "11bb": {
+          "11": {
+            ".radix_ph": "0x741ba4788b06907f8c99c60a6f483f885cc1b4fb27f9e1bed71dfd1d8a213214"
+          },
+          ".radix_ph": "0x099ad81295e3257147362606afc34b47757dd5c1508d441e248302be8577ed44",
+          "00": {
+            ".radix_ph": "0x3dfb52c0d974feb0559c9efafa996fb286717785e98871336e68ffb52d04bdf4"
+          },
+          "bb": {
+            ".label": "0x11bbbb",
+            ".proof_hash": "childProof2",
+            ".radix_ph": "0xbbc5610ad726c88350abbe6513ab8f7441cbe8ff09ece86642a827feb53ce184"
+          }
+        }
+      });
     });
   });
 });
diff --git a/unittest/state-util.test.js b/unittest/state-util.test.js
index 2b0dff28d..4a5d95783 100644
--- a/unittest/state-util.test.js
+++ b/unittest/state-util.test.js
@@ -21,9 +21,10 @@ const {
   deleteStateTreeVersion,
   makeCopyOfStateTree,
   equalStateTrees,
-  setProofHashForStateTree,
-  updateProofHashForAllRootPaths,
-  verifyProofHashForStateTree
+  updateStateInfoForAllRootPaths,
+  updateStateInfoForStateTree,
+  verifyProofHashForStateTree,
+  getProofOfStatePath,
 } = require('../db/state-util');
 const { STATE_LABEL_LENGTH_LIMIT } = require('../common/constants');
 const { GET_OPTIONS_INCLUDE_ALL } = require('./test-util');
@@ -108,7 +109,7 @@ describe("state-util", () => {
           })), {isValid: false, invalidPath: '/some'});
     })
 
-    it("when writable path w/o shard config", () => {
+    it("when writable path without shard config", () => {
       assert.deepEqual(isWritablePathWithSharding(
           ['some', 'path'],
           StateNode.fromJsObject({
@@ -2085,7 +2086,7 @@ describe("state-util", () => {
       stateTree = new StateNode(ver3);
       stateTree.setChild('label1', child1);
       stateTree.setChild('label2', child2);
-      setProofHashForStateTree(stateTree);
+      updateStateInfoForStateTree(stateTree);
     })
 
     it("leaf node", () => {
@@ -2093,7 +2094,7 @@ describe("state-util", () => {
 
       // Delete a leaf node without version.
       const stateNode1 = StateNode.fromJsObject(true);
-      setProofHashForStateTree(stateNode1);
+      updateStateInfoForStateTree(stateNode1);
       const numNodes1 = deleteStateTree(stateNode1);
       expect(numNodes1).to.equal(1);
       expect(stateNode1.numChildren()).to.equal(0);
@@ -2103,7 +2104,7 @@ describe("state-util", () => {
 
       // Delete a leaf node with version.
       const stateNode2 = StateNode.fromJsObject(true, ver1);
-      setProofHashForStateTree(stateNode2);
+      updateStateInfoForStateTree(stateNode2);
       const numNodes2 = deleteStateTree(stateNode2);
       expect(numNodes2).to.equal(1);
       expect(stateNode2.numChildren()).to.equal(0);
@@ -2147,13 +2148,13 @@ describe("state-util", () => {
       node = new StateNode(ver3);
       node.setChild('label1', child1);
       node.setChild('label2', child2);
-      setProofHashForStateTree(node);
+      updateStateInfoForStateTree(node);
     })
 
     it("leaf node", () => {
       // Delete a leaf node without version.
       const stateNode1 = StateNode.fromJsObject(true);
-      setProofHashForStateTree(stateNode1);
+      updateStateInfoForStateTree(stateNode1);
       const numNodes1 = deleteStateTreeVersion(stateNode1);
       expect(numNodes1).to.equal(1);
       expect(stateNode1.getValue()).to.equal(null);
@@ -2162,7 +2163,7 @@ describe("state-util", () => {
 
       // Delete a leaf node with a different version.
       const stateNode2 = StateNode.fromJsObject(true, 'ver2');
-      setProofHashForStateTree(stateNode2);
+      updateStateInfoForStateTree(stateNode2);
       const numNodes2 = deleteStateTreeVersion(stateNode2);
       expect(numNodes2).to.equal(1);
       expect(stateNode2.getValue()).to.equal(null);
@@ -2171,7 +2172,7 @@ describe("state-util", () => {
 
       // Delete a leaf node with the same version.
       const stateNode3 = StateNode.fromJsObject(true, ver1);
-      setProofHashForStateTree(stateNode3);
+      updateStateInfoForStateTree(stateNode3);
       const numNodes3 = deleteStateTreeVersion(stateNode3);
       expect(numNodes3).to.equal(1);
       expect(stateNode3.getValue()).to.equal(null);
@@ -2181,7 +2182,7 @@ describe("state-util", () => {
       // Delete a leaf node with the same version but with non-zero numParents() value.
       const stateNode4 = StateNode.fromJsObject(true, ver1);
       parent.setChild(nodeLabel, stateNode4);
-      setProofHashForStateTree(stateNode4);
+      updateStateInfoForStateTree(stateNode4);
       const numNodes4 = deleteStateTreeVersion(stateNode4);
       expect(numNodes4).to.equal(0);
       expect(stateNode4.getValue()).to.equal(true);
@@ -2238,7 +2239,7 @@ describe("state-util", () => {
         ".num_parents": 1,
         ".num_parents:label1": 1,
         ".num_parents:label2": 1,
-        ".proof_hash": "0xa540d9d1906f4579604302acdee0b4c9742f537eb5f8397fb9a43ed458dad439",
+        ".proof_hash": "0x4ef3be0ba4fd9c5bc7994d3ed87ec958e11f97f1c974fba94037711e058328d6",
         ".proof_hash:label1": "0xb41f4a6e100333ddd8e8dcc01ca1fed23662d9faaec359ed255d21a900cecd08",
         ".proof_hash:label2": "0x7597bdc763c23c44e90f26c63d7eac963cc0d0aa8a0a3268e7f5691c5361d942",
         ".tree_height": 1,
@@ -2480,261 +2481,365 @@ describe("state-util", () => {
     })
   })
 
-  describe("setProofHashForStateTree", () => {
-    it("generates a proof hash along with the given stateTree", () => {
-      const jsObject = {
-        level0: {
-          level1: {
-            foo: 'bar',
-            baz: 'caz'
+  describe("empty nodes removal", () => {
+    const label1 = '0x0001';
+    const label11 = '0x0011';
+    const label111 = '0x0111';
+    const label1111 = '0x1111';
+    const label12 = '0x0012';
+    const label121 = '0x0121';
+    let stateTree;
+    let child1;
+    let child11;
+    let child111;
+    let child1111;
+    const jsObject = {
+      [label1]: {
+        [label11]: {
+          [label111]: {
+            [label1111]: null,
           }
         },
-        another_route: {
-          test: 10
+        [label12]: {
+          [label121]: 'V0121'
         }
-      };
-      const stateTree = StateNode.fromJsObject(jsObject);
-      const level0Node = stateTree.getChild('level0');
-      const level1Node = level0Node.getChild('level1');
-      const fooNode = level1Node.getChild('foo');
-      const bazNode = level1Node.getChild('baz');
-      const anotherNode = stateTree.getChild('another_route');
-      const testNode = anotherNode.getChild('test');
-
-      const numAffectedNodes = setProofHashForStateTree(level0Node);
-      expect(numAffectedNodes).to.equal(4);
-      // Checks proof hashes.
-      expect(level0Node.getProofHash()).to.equal(level0Node.buildProofHash());
-      expect(level1Node.getProofHash()).to.equal(level1Node.buildProofHash());
-      expect(fooNode.getProofHash()).to.equal(fooNode.buildProofHash());
-      expect(bazNode.getProofHash()).to.equal(bazNode.buildProofHash());
-      expect(stateTree.getChild('another_route').getChild('test').getProofHash()).to.equal(null);
-      expect(stateTree.getChild('another_route').getProofHash()).to.equal(null);
-      expect(stateTree.getProofHash()).to.equal(null);
-      // Checks tree heights.
-      expect(fooNode.getTreeHeight()).to.equal(0);
-      expect(bazNode.getTreeHeight()).to.equal(0);
-      expect(level1Node.getTreeHeight()).to.equal(1);
-      expect(level0Node.getTreeHeight()).to.equal(2);
-      expect(anotherNode.getTreeHeight()).to.equal(0);
-      expect(testNode.getTreeHeight()).to.equal(0);
-      // Checks tree sizes.
-      expect(fooNode.getTreeSize()).to.equal(1);
-      expect(bazNode.getTreeSize()).to.equal(1);
-      expect(level1Node.getTreeSize()).to.equal(3);
-      expect(level0Node.getTreeSize()).to.equal(4);
-      expect(anotherNode.getTreeSize()).to.equal(0);
-      expect(testNode.getTreeSize()).to.equal(0);
-      // Checks tree bytes.
-      expect(fooNode.getTreeBytes()).to.equal(166);
-      expect(bazNode.getTreeBytes()).to.equal(166);
-      expect(level1Node.getTreeBytes()).to.equal(504);
-      expect(level0Node.getTreeBytes()).to.equal(676);
-      expect(anotherNode.getTreeBytes()).to.equal(0);
-      expect(testNode.getTreeBytes()).to.equal(0);
+      }
+    };
+
+    beforeEach(() => {
+      stateTree = StateNode.fromJsObject(jsObject);
+      child1 = stateTree.getChild(label1);
+      child11 = child1.getChild(label11);
+      child111 = child11.getChild(label111);
+      child1111 = child111.getChild(label1111);
     });
-  });
 
-  describe("updateProofHashForAllRootPaths", () => {
-    it("updates proof hashes for a single root path", () => {
-      const jsObject = {
-        level0: {
-          level1: {
-            level2: {
-              foo: 'bar',
-              baz: 'caz'
+    it("updateStateInfoForAllRootPaths on empty node with a single root path", () => {
+      assert.deepEqual(stateTree.toJsObject(), {
+        "0x0001": {
+          "0x0011": {
+            "0x0111": {
+              "0x1111": null
             }
           },
-          another_route: {
-            test: -1000
+          "0x0012": {
+            "0x0121": "V0121"
           }
         }
-      };
-      const rootNode = StateNode.fromJsObject(jsObject);
-      const level0Node = rootNode.getChild('level0');
-      const level1Node = level0Node.getChild('level1');
-      const level2Node = level1Node.getChild('level2');
-      const anotherNode = level0Node.getChild('another_route');
-
-      level2Node.setTreeHeight(1);
-      level2Node.setTreeSize(3);
-      level2Node.setTreeBytes(150);  // An arbitrary value
-      anotherNode.setTreeHeight(1);
-      anotherNode.setTreeSize(2);
-      anotherNode.setTreeBytes(100);  // An arbitrary value
-
-      const numAffectedNodes = updateProofHashForAllRootPaths(['level0', 'level1'], rootNode);
-      expect(numAffectedNodes).to.equal(3);
-      // Checks proof hashes.
-      expect(level2Node.getChild('foo').getProofHash()).to.equal(null);
-      expect(level2Node.getChild('baz').getProofHash()).to.equal(null);
-      expect(level2Node.getProofHash()).to.equal(null);
-      expect(anotherNode.getChild('test').getProofHash()).to.equal(null);
-      expect(anotherNode.getProofHash()).to.equal(null);
-      expect(level1Node.getProofHash()).to.equal(level1Node.buildProofHash());
-      expect(level0Node.getProofHash()).to.equal(level0Node.buildProofHash());
-      expect(rootNode.getProofHash()).to.equal(rootNode.buildProofHash());
-      // Checks tree heights.
-      expect(level1Node.getTreeHeight()).to.equal(2);
-      expect(level0Node.getTreeHeight()).to.equal(3);
-      expect(rootNode.getTreeHeight()).to.equal(4);
-      // Checks tree sizes.
-      expect(level1Node.getTreeSize()).to.equal(4);
-      expect(level0Node.getTreeSize()).to.equal(7);
-      expect(rootNode.getTreeSize()).to.equal(8);
-      // Checks tree bytes.
-      expect(level1Node.getTreeBytes()).to.equal(322);
-      expect(level0Node.getTreeBytes()).to.equal(620);
-      expect(rootNode.getTreeBytes()).to.equal(792);
+      });
+      const numAffectedNodes =
+          updateStateInfoForAllRootPaths([label1, label11, label111, label1111], stateTree);
+      expect(numAffectedNodes).to.equal(5);
+      assert.deepEqual(stateTree.toJsObject(), {
+        "0x0001": {
+          "0x0012": {
+            "0x0121": "V0121"
+          }
+        }
+      });
     });
 
-    it("updates proof hashes for multiple root paths", () => {
-      const jsObject = {
-        level0: {
-          level1: {
-            level2: {
-              foo: 'bar',
-              baz: 'caz'
+    it("updateStateInfoForAllRootPaths on empty node with multiple root paths", () => {
+      const child111Clone = child111.clone();
+      const child11Clone = new StateNode();
+      child11Clone.setChild(label111, child111Clone);
+      const child1Clone = new StateNode();
+      child1Clone.setChild(label11, child11Clone);
+      const stateTreeClone = new StateNode();
+      stateTreeClone.setChild(label1, child1Clone);
+      const child3 = new StateNode();
+      child3.setValue('V0003');
+      const label3 = '0x003';
+      stateTreeClone.setChild(label3, child3);
+
+      assert.deepEqual(stateTree.toJsObject(), {
+        "0x0001": {
+          "0x0011": {
+            "0x0111": {
+              "0x1111": null
             }
           },
-          another_route: {
-            test: -1000
+          "0x0012": {
+            "0x0121": "V0121"
           }
         }
-      };
-      const rootNode = StateNode.fromJsObject(jsObject);
-      const level0Node = rootNode.getChild('level0');
-      const level1Node = level0Node.getChild('level1');
-      const level2Node = level1Node.getChild('level2');
-      const anotherNode = level0Node.getChild('another_route');
-      const rootClone = rootNode.clone();
-      const level0Clone = level0Node.clone();
-      const level1Clone = level1Node.clone();
-      const level2Clone = level2Node.clone();
-      const anotherClone = anotherNode.clone();
-
-      const numAffectedNodes = updateProofHashForAllRootPaths(['level0', 'level1'], rootNode);
-      expect(numAffectedNodes).to.equal(5);
-
-      // Checks proof hashes.
-      expect(level2Node.getChild('foo').getProofHash()).to.equal(null);
-      expect(level2Node.getChild('baz').getProofHash()).to.equal(null);
-      expect(level2Node.getProofHash()).to.equal(null);
-      expect(level2Clone.getProofHash()).to.equal(null);
-
-      expect(anotherNode.getChild('test').getProofHash()).to.equal(null);
-      expect(anotherNode.getProofHash()).to.equal(null);
-      expect(anotherClone.getProofHash()).to.equal(null);
-
-      expect(level1Node.getProofHash()).to.equal(level1Node.buildProofHash());
-      expect(level1Clone.getProofHash()).to.equal(null);
-
-      expect(level0Node.getProofHash()).to.equal(level0Node.buildProofHash());
-      expect(level0Clone.getProofHash()).to.equal(level0Clone.buildProofHash());
-      expect(level0Clone.getProofHash()).to.equal(level0Node.getProofHash());
-
-      expect(rootNode.getProofHash()).to.equal(rootNode.buildProofHash());
-      expect(rootClone.getProofHash()).to.equal(rootClone.buildProofHash());
-      expect(rootClone.getProofHash()).to.equal(rootNode.getProofHash());
+      });
+      assert.deepEqual(stateTreeClone.toJsObject(), {
+        "0x0001": {
+          "0x0011": {
+            "0x0111": {
+              "0x1111": null
+            }
+          }
+        },
+        "0x003": "V0003"
+      });
+      assert.deepEqual(child1111.getParentNodes(), [child111, child111Clone]);
+      const numAffectedNodes =
+          updateStateInfoForAllRootPaths([label1, label11, label111, label1111], stateTree);
+      expect(numAffectedNodes).to.equal(10);
+      assert.deepEqual(stateTree.toJsObject(), {
+        "0x0001": {
+          "0x0012": {
+            "0x0121": "V0121"
+          }
+        }
+      });
+      assert.deepEqual(stateTreeClone.toJsObject(), {
+        "0x003": "V0003"
+      });
     });
 
-    it("updates proof hashes for multiple root paths with deleted nodes", () => {
-      const jsObject = {
-        level0: {
-          level1: {
-            level2: {
-              foo: 'bar',
-              baz: 'caz'
+    it("updateStateInfoAllRootPaths on non-empty node", () => {
+      assert.deepEqual(stateTree.toJsObject(), {
+        "0x0001": {
+          "0x0011": {
+            "0x0111": {
+              "0x1111": null
             }
           },
-          another_route: {
-            test: -1000
+          "0x0012": {
+            "0x0121": "V0121"
           }
         }
-      };
-      const rootNode = StateNode.fromJsObject(jsObject);
-      const level0Node = rootNode.getChild('level0');
-      const level1Node = level0Node.getChild('level1');
-      const level2Node = level1Node.getChild('level2');
-      const anotherNode = level0Node.getChild('another_route');
-      const rootClone = rootNode.clone();
-      const level0Clone = level0Node.clone();
-      const level1Clone = level1Node.clone();
-      const level2Clone = level2Node.clone();
-      const anotherClone = anotherNode.clone();
-
-      const numAffectedNodes = updateProofHashForAllRootPaths(
-          ['level0', 'level1', 'deleted1', 'deleted2'], rootNode);  // with deleted nodes
+      });
+      const numAffectedNodes =
+          updateStateInfoForAllRootPaths([label1, label11, label111], stateTree);
+      expect(numAffectedNodes).to.equal(3);
+      assert.deepEqual(stateTree.toJsObject(), {
+        "0x0001": {
+          "0x0011": {
+            "0x0111": {
+              "0x1111": null
+            }
+          },
+          "0x0012": {
+            "0x0121": "V0121"
+          }
+        }
+      });
+    });
+
+    it("updateStateInfoForAllRootPaths with deleted nodes", () => {
+      // with deleted nodes
+      const numAffectedNodes = updateStateInfoForAllRootPaths(
+          [label1, label11, label111, label1111, 'deleted1', 'deleted2'], stateTree);
+      expect(numAffectedNodes).to.equal(5);
+      assert.deepEqual(stateTree.toJsObject(), {
+        "0x0001": {
+          "0x0012": {
+            "0x0121": "V0121"
+          }
+        }
+      });
+    })
+  });
+
+  describe("state info updates", () => {
+    const label1 = '0x0001';
+    const label11 = '0x0011';
+    const label111 = '0x0111';
+    const label1111 = '0x1111';
+    const label1112 = '0x1112';
+    const label2 = '0x0002';
+    const label21 = '0x0021';
+    let stateTree;
+    let child1;
+    let child11;
+    let child111;
+    let child1111;
+    let child1112;
+    let child2;
+    let child21;
+    const jsObject = {
+      [label1]: {
+        [label11]: {
+          [label111]: {
+            [label1111]: 'V1111',
+            [label1112]: 'V1112'
+          }
+        }
+      },
+      [label2]: {
+        [label21]: 'V0021'
+      }
+    };
+
+    beforeEach(() => {
+      stateTree = StateNode.fromJsObject(jsObject);
+      child1 = stateTree.getChild(label1);
+      child11 = child1.getChild(label11);
+      child111 = child11.getChild(label111);
+      child1111 = child111.getChild(label1111);
+      child1112 = child111.getChild(label1112);
+      child2 = stateTree.getChild(label2);
+      child21 = child2.getChild(label21);
+    });
+
+    it("updateStateInfoForStateTree", () => {
+      const numAffectedNodes = updateStateInfoForStateTree(child1);
       expect(numAffectedNodes).to.equal(5);
+      // Checks proof hashes.
+      expect(child1111.verifyProofHash()).to.equal(true);
+      expect(child1112.verifyProofHash()).to.equal(true);
+      expect(child111.verifyProofHash()).to.equal(true);
+      expect(child11.verifyProofHash()).to.equal(true);
+      expect(child1.verifyProofHash()).to.equal(true);
+      expect(child21.verifyProofHash()).to.equal(false);
+      expect(child2.verifyProofHash()).to.equal(false);
+      expect(stateTree.verifyProofHash()).to.equal(false);
+      // Checks tree heights.
+      expect(child1111.getTreeHeight()).to.equal(0);
+      expect(child1112.getTreeHeight()).to.equal(0);
+      expect(child111.getTreeHeight()).to.equal(1);
+      expect(child11.getTreeHeight()).to.equal(2);
+      expect(child1.getTreeHeight()).to.equal(3);
+      expect(child21.getTreeHeight()).to.equal(0);
+      expect(child2.getTreeHeight()).to.equal(0);
+      expect(stateTree.getTreeHeight()).to.equal(0);
+      // Checks tree sizes.
+      expect(child1111.getTreeSize()).to.equal(1);
+      expect(child1112.getTreeSize()).to.equal(1);
+      expect(child111.getTreeSize()).to.equal(3);
+      expect(child11.getTreeSize()).to.equal(4);
+      expect(child1.getTreeSize()).to.equal(5);
+      expect(child21.getTreeSize()).to.equal(0);
+      expect(child2.getTreeSize()).to.equal(0);
+      expect(stateTree.getTreeSize()).to.equal(0);
+      // Checks tree bytes.
+      expect(child1111.getTreeBytes()).to.not.equal(0);  // non-zero value
+      expect(child1112.getTreeBytes()).to.not.equal(0); // non-zero value
+      expect(child111.getTreeBytes()).to.not.equal(0); // non-zero value
+      expect(child11.getTreeBytes()).to.not.equal(0); // non-zero value
+      expect(child1.getTreeBytes()).to.not.equal(0); // non-zero value
+      expect(child21.getTreeBytes()).to.equal(0);
+      expect(child2.getTreeBytes()).to.equal(0);
+      expect(stateTree.getTreeBytes()).to.equal(0);
+    });
 
+    it("updateStateInfoForAllRootPaths with a single root path", () => {
+      const numAffectedNodes =
+          updateStateInfoForAllRootPaths([label1, label11, label111, label1112], stateTree);
+      expect(numAffectedNodes).to.equal(4);
       // Checks proof hashes.
-      expect(level2Node.getChild('foo').getProofHash()).to.equal(null);
-      expect(level2Node.getChild('baz').getProofHash()).to.equal(null);
-      expect(level2Node.getProofHash()).to.equal(null);
-      expect(level2Clone.getProofHash()).to.equal(null);
+      expect(child1111.verifyProofHash()).to.equal(false);
+      expect(child1112.verifyProofHash()).to.equal(false);
+      expect(child111.verifyProofHash(label1112)).to.equal(true);  // verified
+      expect(child11.verifyProofHash()).to.equal(true);  // verified
+      expect(child21.verifyProofHash()).to.equal(false);
+      expect(child2.verifyProofHash()).to.equal(false);
+      expect(child1.verifyProofHash()).to.equal(true);  // verified
+      expect(stateTree.verifyProofHash(label1)).to.equal(true);  // verified
+
+      // Checks tree heights.
+      expect(child1111.getTreeHeight()).to.equal(0);
+      expect(child1112.getTreeHeight()).to.equal(0);
+      expect(child111.getTreeHeight()).to.equal(child111.computeTreeHeight());
+      expect(child11.getTreeHeight()).to.equal(child11.computeTreeHeight());
+      expect(child1.getTreeHeight()).to.equal(child1.computeTreeHeight());
+      expect(child21.getTreeHeight()).to.equal(0);
+      expect(child2.getTreeHeight()).to.equal(0);
+      expect(stateTree.getTreeHeight()).to.equal(stateTree.computeTreeHeight());
+
+      // Checks tree sizes.
+      expect(child1111.getTreeSize()).to.equal(0);
+      expect(child1112.getTreeSize()).to.equal(0);
+      expect(child111.getTreeSize()).to.equal(child111.computeTreeSize());
+      expect(child11.getTreeSize()).to.equal(child11.computeTreeSize());
+      expect(child1.getTreeSize()).to.equal(child1.computeTreeSize());
+      expect(child21.getTreeSize()).to.equal(0);
+      expect(child2.getTreeSize()).to.equal(0);
+      expect(stateTree.getTreeSize()).to.equal(stateTree.computeTreeSize());
 
-      expect(anotherNode.getChild('test').getProofHash()).to.equal(null);
-      expect(anotherNode.getProofHash()).to.equal(null);
-      expect(anotherClone.getProofHash()).to.equal(null);
+      // Checks tree bytes.
+      expect(child1111.getTreeBytes()).to.equal(0);
+      expect(child1112.getTreeBytes()).to.equal(0);
+      expect(child111.getTreeBytes()).to.equal(child111.computeTreeBytes());
+      expect(child11.getTreeBytes()).to.equal(child11.computeTreeBytes());
+      expect(child1.getTreeBytes()).to.equal(child1.computeTreeBytes());
+      expect(child21.getTreeBytes()).to.equal(0);
+      expect(child2.getTreeBytes()).to.equal(0);
+      expect(stateTree.getTreeBytes()).to.equal(stateTree.computeTreeBytes());
+    });
 
-      expect(level1Node.getProofHash()).to.equal(level1Node.buildProofHash());
-      expect(level1Clone.getProofHash()).to.equal(null);
+    it("updateStateInfoForAllRootPaths with multiple root paths", () => {
+      const stateTreeClone = stateTree.clone();
+      const child1Clone = child1.clone();
+      const child11Clone = child11.clone();
+      const child111Clone = child111.clone();
+      const child2Clone = child2.clone();
 
-      expect(level0Node.getProofHash()).to.equal(level0Node.buildProofHash());
-      expect(level0Clone.getProofHash()).to.equal(level0Clone.buildProofHash());
-      expect(level0Clone.getProofHash()).to.equal(level0Node.getProofHash());
+      const numAffectedNodes =
+          updateStateInfoForAllRootPaths([label1, label11, label111, label1112], stateTree);
+      expect(numAffectedNodes).to.equal(8);
 
-      expect(rootNode.getProofHash()).to.equal(rootNode.buildProofHash());
-      expect(rootClone.getProofHash()).to.equal(rootClone.buildProofHash());
-      expect(rootClone.getProofHash()).to.equal(rootNode.getProofHash());
+      // Checks proof hashes.
+      expect(child1111.verifyProofHash()).to.equal(false);
+      expect(child1112.verifyProofHash()).to.equal(false);  // not verified!!
+      expect(child111.verifyProofHash(label1112)).to.equal(true);  // verified
+      expect(child111Clone.verifyProofHash(label1112)).to.equal(true);  // verified
+      expect(child11.verifyProofHash()).to.equal(true);  // verified
+      expect(child11Clone.verifyProofHash()).to.equal(true);  // verified
+      expect(child11Clone.getProofHash()).to.equal(child11.getProofHash());
+      expect(child1.verifyProofHash()).to.equal(true);  // verified
+      expect(child1Clone.verifyProofHash()).to.equal(true);  // verified
+      expect(child1Clone.getProofHash()).to.equal(child1.getProofHash());
+      expect(child21.verifyProofHash()).to.equal(false);
+      expect(child2.verifyProofHash()).to.equal(false);
+      expect(child2Clone.verifyProofHash()).to.equal(false);
+      expect(stateTree.verifyProofHash(label1)).to.equal(true);  // verified
+      expect(stateTreeClone.verifyProofHash(label1)).to.equal(true);  // verified
+      expect(stateTreeClone.getProofHash()).to.equal(stateTree.getProofHash());
     });
-  });
 
-  describe("verifyProofHashForStateTree", () => {
-    it("verify correct proof hashes as true", () => {
-      const jsObject = {
-        level0: {
-          level1: {
-            level2: {
-              foo: 'bar',
-              baz: 'caz'
-            }
-          },
-          another_route: {
-            test: -1000
-          }
-        }
-      };
-      const rootNode = StateNode.fromJsObject(jsObject);
-      setProofHashForStateTree(rootNode);
-      expect(verifyProofHashForStateTree(rootNode)).to.equal(true);
+    it("updateStateInfoForAllRootPaths with deleted nodes", () => {
+      const numAffectedNodes = updateStateInfoForAllRootPaths(
+          [label1, label11, label111, 'deleted1', 'deleted2'], stateTree);  // with deleted nodes
+      expect(numAffectedNodes).to.equal(4);
+
+      // Checks proof hashes.
+      expect(child1111.verifyProofHash()).to.equal(false);
+      expect(child1112.verifyProofHash()).to.equal(false);
+      expect(child111.verifyProofHash()).to.equal(true);  // verified!!
+      expect(child11.verifyProofHash()).to.equal(true);  // verified
+      expect(child21.verifyProofHash()).to.equal(false);
+      expect(child2.verifyProofHash()).to.equal(false);
+      expect(child1.verifyProofHash()).to.equal(true);  // verified
+      expect(stateTree.verifyProofHash(label1)).to.equal(true);  // verified
     });
 
-    it("verify wrong proof hashes as false", () => {
-      const jsObject = {
-        level0: {
-          level11: {
-            level2: {
-              foo: 'bar',
-              baz: 'caz'
-            }
+    it("verifyProofHashForStateTree ", () => {
+      updateStateInfoForStateTree(stateTree);
+      expect(verifyProofHashForStateTree(stateTree)).to.equal(true);
+      child111.setProofHash('new ph');
+      expect(verifyProofHashForStateTree(stateTree)).to.equal(false);
+    });
+
+    it("getProofOfState", () => {
+      updateStateInfoForStateTree(stateTree);
+      assert.deepEqual(getProofOfStatePath(stateTree, [label1, label11]), {
+        ".radix_ph": "0xeef6cf891adc1b4755cb54085116c08d7ced1afe8eee3bdaac2259d935b2befe",
+        "000": {
+          "1": {
+            ".label": "0x0001",
+            ".proof_hash": {
+              ".radix_ph": "0x7ba5e5356546d605d7b44d9fce969e41520b81b5df436cb57a9209e1fefab25b",
+              "0011": {
+                ".label": "0x0011",
+                ".proof_hash": {
+                  ".proof_hash": "0x567383e2ed5a49d908498eda42457ce1ed07c3b6672b75c3e0be5d0da8de4b9d"
+                },
+                ".radix_ph": "0x9361b41ef0b1b88c2ea20a7aeb471f3c84af681b6a747a0c09a47794189e1c51"
+              }
+            },
+            ".radix_ph": "0xdfa952d88be9321937e4ce6918c03312c40725472ee08d6d61a3b1f277e2f38b"
           },
-          level12: {
-            level2: {
-              foo2: 'bar2'
-            }
+          "2": {
+            ".radix_ph": "0xa64fc83d2b5a4193e285cf17f9f2ad02898730a74441c995409d3d9be3b63dc6"
           },
-          another_route: {
-            test: -1000
-          }
+          ".radix_ph": "0x0f1fdb35bd8e9ec757d12c8a3dafdcd83437aa392b1fcd22d1b0c0ee273aed31"
         }
-      };
-      const rootNode = StateNode.fromJsObject(jsObject);
-      const level0Node = rootNode.getChild('level0');
-      const level12Node = level0Node.getChild('level12');
-      setProofHashForStateTree(rootNode);
-      level12Node.setProofHash('0xdeadbeaf');
-      expect(verifyProofHashForStateTree(rootNode)).to.equal(false);
+      });
     });
   });
 })
\ No newline at end of file
diff --git a/unittest/test-util.js b/unittest/test-util.js
index 336362878..800f49908 100644
--- a/unittest/test-util.js
+++ b/unittest/test-util.js
@@ -1,5 +1,6 @@
 const path = require('path');
 const fs = require("fs");
+const _ = require("lodash");
 const syncRequest = require('sync-request');
 const { Block } = require('../blockchain/block');
 const DB = require('../db');
@@ -71,12 +72,12 @@ function addBlock(node, txs, votes, validators) {
   finalDb.executeTransactionList(txs, false, true, lastBlock.number + 1);
   node.syncDbAndNonce(`${StateVersions.NODE}:${lastBlock.number + 1}`);
   node.addNewBlock(Block.create(
-      lastBlock.hash, votes, txs, lastBlock.number + 1, lastBlock.epoch + 1, '',
+      lastBlock.hash, votes, {}, txs, lastBlock.number + 1, lastBlock.epoch + 1, '',
       node.account.address, validators, 0, 0));
 }
 
 async function waitUntilTxFinalized(servers, txHash) {
-  const MAX_ITERATION = 200;
+  const MAX_ITERATION = 40;
   let iterCount = 0;
   const unchecked = new Set(servers);
   while (true) {
@@ -95,7 +96,7 @@ async function waitUntilTxFinalized(servers, txHash) {
         unchecked.delete(server);
       }
     }
-    await CommonUtil.sleep(500);
+    await CommonUtil.sleep(3000);
     iterCount++;
   }
 }
@@ -109,13 +110,46 @@ async function waitForNewBlocks(server, waitFor = 1) {
   }
 }
 
+async function waitUntilNetworkIsReady(serverList) {
+  const MAX_ITERATION = 40;
+  let iterCount = 0;
+  const unchecked = new Set(serverList);
+  while (true) {
+    if (!unchecked.size) {
+      return true;
+    }
+    if (iterCount >= MAX_ITERATION) {
+      console.log(`Iteration count exceeded its limit before the network is ready (${JSON.stringify([...unchecked])})`);
+      return false;
+    }
+    for (const server of unchecked) {
+      try {
+        const healthCheck = parseOrLog(syncRequest('GET', server + '/health_check')
+            .body
+            .toString('utf-8'));
+        if (healthCheck === true) {
+          unchecked.delete(server);
+        }
+      } catch (e) {
+        // server may not be ready yet
+      }
+    }
+    await CommonUtil.sleep(3000);
+    iterCount++;
+  }
+}
+
 async function waitUntilNodeSyncs(server) {
   let isSyncing = true;
   while (isSyncing) {
-    isSyncing = parseOrLog(syncRequest('POST', server + '/json-rpc',
-        {json: {jsonrpc: '2.0', method: 'net_syncing', id: 0,
-                params: {protoVer: CURRENT_PROTOCOL_VERSION}}})
-        .body.toString('utf-8')).result.result;
+    try {
+      isSyncing = parseOrLog(syncRequest('POST', server + '/json-rpc',
+          {json: {jsonrpc: '2.0', method: 'net_syncing', id: 0,
+                  params: {protoVer: CURRENT_PROTOCOL_VERSION}}})
+          .body.toString('utf-8')).result.result;
+    } catch (e) {
+      // server may not be ready yet
+    }
     await CommonUtil.sleep(1000);
   }
 }
@@ -165,6 +199,16 @@ function getBlockByNumber(server, number) {
       .body.toString('utf-8')).result;
 }
 
+function eraseStateGas(result, appNameList = []) {
+  const erased = JSON.parse(JSON.stringify(result));
+  _.set(erased, 'gas_amount_charged', 'erased');
+  _.set(erased, 'gas_amount_total.state.service', 'erased');
+  for (const appName of appNameList) {
+    _.set(erased, `gas_amount_total.state.app.${appName}`, 'erased');
+  }
+  return erased;
+}
+
 module.exports = {
   GET_OPTIONS_INCLUDE_ALL,
   readConfigFile,
@@ -173,10 +217,12 @@ module.exports = {
   addBlock,
   waitUntilTxFinalized,
   waitForNewBlocks,
+  waitUntilNetworkIsReady,
   waitUntilNodeSyncs,
   parseOrLog,
   setUpApp,
   getLastBlock,
   getLastBlockNumber,
   getBlockByNumber,
+  eraseStateGas,
 };
diff --git a/yarn.lock b/yarn.lock
index 6547a36fd..8d0992fef 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3531,9 +3531,9 @@ path-key@^2.0.1:
   integrity sha1-QRyttXTFoUDTpLGRDUDYDMn0C0A=
 
 path-parse@^1.0.6:
-  version "1.0.6"
-  resolved "https://registry.yarnpkg.com/path-parse/-/path-parse-1.0.6.tgz#d62dbb5679405d72c4737ec58600e9ddcf06d24c"
-  integrity sha512-GSmOT2EbHrINBf9SR7CDELwlJ8AENk3Qn7OikK4nFYAu3Ote2+JYNVvkpAEQm3/TLNEJFD/xZJjzyxg3KBWOzw==
+  version "1.0.7"
+  resolved "https://registry.yarnpkg.com/path-parse/-/path-parse-1.0.7.tgz#fbc114b60ca42b30d9daf5858e4bd68bbedb6735"
+  integrity sha512-LDJzPVEEEPR+y48z93A0Ed0yXb8pAByGWo/k5YYdYgpY2/2EsOsksJrq7lOHxryrVOn1ejG6oAp8ahvOIQD8sw==
 
 path-to-regexp@0.1.7:
   version "0.1.7"