diff --git a/contracts/registration/Registration.sol b/contracts/registration/Registration.sol
index b0481f3..90d2221 100644
--- a/contracts/registration/Registration.sol
+++ b/contracts/registration/Registration.sol
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: MIT
 pragma solidity 0.8.16;
 
-import {PoseidonUnit1L, PoseidonUnit2L, PoseidonUnit5L} from "@iden3/contracts/lib/Poseidon.sol";
+import {PoseidonUnit1L, PoseidonUnit2L, PoseidonUnit3L, PoseidonUnit5L} from "@iden3/contracts/lib/Poseidon.sol";
 
 import {Initializable} from "@openzeppelin/contracts/proxy/utils/Initializable.sol";
 
@@ -23,6 +23,9 @@ contract Registration is PoseidonSMT, Initializable {
     mapping(bytes32 => bytes32) public hashedRSAKeyToInternalKey;
     mapping(bytes32 => bytes32) public internalKeyToHashedRSAKey;
 
+    mapping(bytes32 => uint256) public passportIdentitiesCounter;
+    mapping(bytes32 => uint256) public identityCreationTimestamps;
+
     mapping(bytes32 => bool) internal _usedSignatures;
 
     event Registered(bytes32 hashedRSAKey, bytes32 hashedInternalKey);
@@ -78,14 +81,19 @@ contract Registration is PoseidonSMT, Initializable {
 
         require(verifier.verifyProof(pubSignals_, zkPoints_), "Registration: invalid zk proof");
 
-        uint256 index_ = PoseidonUnit2L.poseidon([hashedRSAKey_, hashedInternalKey_]);
-
         _usedSignatures[sigHash_] = true;
 
         hashedRSAKeyToInternalKey[bytes32(hashedRSAKey_)] = bytes32(hashedInternalKey_);
         internalKeyToHashedRSAKey[bytes32(hashedInternalKey_)] = bytes32(hashedRSAKey_);
 
-        _add(bytes32(index_), bytes32(PoseidonUnit2L.poseidon([index_, group1Hash_])));
+        identityCreationTimestamps[bytes32(hashedInternalKey_)] = block.timestamp;
+
+        uint256 index_ = PoseidonUnit2L.poseidon([hashedRSAKey_, hashedInternalKey_]);
+        uint256 value_ = PoseidonUnit3L.poseidon(
+            [group1Hash_, passportIdentitiesCounter[bytes32(hashedRSAKey_)], block.timestamp]
+        );
+
+        _add(bytes32(index_), bytes32(value_));
 
         emit Registered(bytes32(hashedRSAKey_), bytes32(hashedInternalKey_));
     }
diff --git a/deploy/1_setup.migration.ts b/deploy/1_setup.migration.ts
index 32250d3..6c21f44 100644
--- a/deploy/1_setup.migration.ts
+++ b/deploy/1_setup.migration.ts
@@ -8,10 +8,7 @@ const treeHeight = 80;
 const icaoMasterTreeMerkleRoot = "0x2c50ce3aa92bc3dd0351a89970b02630415547ea83c487befbc8b1795ea90c45";
 
 export = async (deployer: Deployer) => {
-  await deployPoseidons(
-    deployer,
-    new Array(6).fill(6).map((_, i) => i + 1),
-  );
+  await deployPoseidons(deployer, [2, 3, 5]);
 
   const registration = await deployer.deploy(Registration__factory);
   const registrationVerifier = await deployer.deploy(RegistrationVerifier__factory);