CoinID: Add token and nft support to coin identity

papers/nbcr-2023-001-coin-identity.md

@@ -19,6 +19,9 @@ We propose to define a UR type standardizing the coin identification by aggregat
 1. Curve of the coin (e.g. *`["secp256k1", "ed25519", "p256 (secp256r1)”, “X25519 (sr25519)”]` ).* This information is mandatory in the case of some blockchain (e.g. Tezos) supporting multiple elliptic curves.
 2. BIP44 coin type as defined in [[SLIP44]](https://github.com/satoshilabs/slips/blob/master/slip-0044.md).
 3. Subtype to define additional information to identify the coin (e.g. the chain ID for an EVM chain).
+4. Contract identifier as subtypes (e.g. ERC20 token address, ERC721 NFTs).
+
+
 
 ### EC Curve Definitions
 
@@ -86,7 +89,7 @@ subtype = 3
 
 The UR type is designed to be easily convertible to a URI format when human readability or deep linking are required.
 
-The URI format is as follows: **`bc-coin://{subtype1.subtype0}.{curve}/type?optional=parameters`**.
+The URI format is as follows: **`bc-coin://{tokenId@subtype1.subtype0}.{curve}/type?optional=parameters`**.
 
 
 We are providing several examples in the following table:
@@ -103,6 +106,26 @@ We are providing several examples in the following table:
 | Polkadot | bc-coin://x25519/354 |
 
 
+
+#### Tokens
+
+Tokens under the respective coin can be distinguished by the `@` seperator. Anything under the left of `@` is considered the contract identifier. 
+For EVM based coin and ERC20 tokens, the contract identifier is the token address. For Elrond its tokenID.
+For ERC721 tokens, the contract identifier is contract address and the token ID. Token ID will be the sub type of contract in this case.
+
+**Examples:**
+
+| Token | Coin | URI coin identity |
+| --- | --- | --- |
+| USDT |ETH | bc-coin://0xdAC17F958D2ee523a2206206994597C13D831ec7@secp256k1/60|
+| USDT |Polygon (MATIC) | bc-coin://[email protected]/60 |
+| [NFT](https://etherscan.io/nft/0x495f947276749ce646f68ac8c248420045cb7b5e/30215980622330187411918288900688501299580125367569939549692495859506871271425) | ETH | bc-coin://30215980622330187411918288900688501299580125367569939549692495859506871271425.0x495f947276749Ce646f68AC8c248420045cb7b5e@secp256k1/60 |
+| USDC | MultiversX (EGLD) | bc-coin://USDC-c76f1f@ed25519/508|
+| USDC | SOL | bc-coin://EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v@ed25519/501|
+
+
+
+
 ### Example/Test Vector 1
 
 * Solana coin 
@@ -180,6 +203,88 @@ A3010802183C03811889
 
 ```
 
+# Example/Test Vector 3
+* USDT Token on Polygon (MATIC)
+* URI: `bc-coin://[email protected]/60`
+
+
+* In the CBOR diagnostic notation:
+
+```
+{
+   1: 8, ; curve-secp256k1
+   2: 60, ; type ETH BIP44
+   3: [137, "@", 263(h'c2132D05D31c914a87C6611C10748AEb04B58e8F')], ; subtype Polygon + contract address
+}
+```
+
+* Encoded as binary using [CBOR-PLAYGROUND]:
+
+```
+A3              # map(3)
+   01           # unsigned(1) curve
+   08           # unsigned(1) secp256k1
+   02           # unsigned(2) type
+   18 3C        # unsigned(60) ETH
+   03           # unsigned(3) sub type
+   83           # array(3) 
+      18 89     # unsigned(137) Polygon Chain Id
+      61        # text(1)
+         40     # "@"
+      D9 0107   # tag(263)
+         54     # bytes(20)
+            C2132D05D31C914A87C6611C10748AEB04B58E8F # contract address
+```
+
+* As a hex string:
+
+```
+A3010802183C038318896140D9010754C2132D05D31C914A87C6611C10748AEB04B58E8F
+```
+
+### Example/Test Vector 4
+
+* NFT on ETH
+* URI: `bc-coin://30215980622330187411918288900688501299580125367569939549692495859506871271425.0x495f947276749Ce646f68AC8c248420045cb7b5e@secp256k1/60`
+
+* In the CBOR diagnostic notation:
+
+```
+{
+   1: 8, ; curve-secp256k1
+   2: 60, ; type ETH BIP44
+   3: ["@", 263(h'495f947276749Ce646f68AC8c248420045cb7b5e)', 30215980622330187411918288900688501299580125367569939549692495859506871271425], ; subtype contract address + token id
+}
+```
+
+* Encoded as binary using [CBOR-PLAYGROUND]:
+
+```
+A3                                      # map(3)
+   01                                   # unsigned(1)
+   08                                   # unsigned(8)
+   02                                   # unsigned(2)
+   18 3C                                # unsigned(60)
+   03                                   # unsigned(3)
+   83                                   # array(3)
+      61                                # text(1)
+         40                             # "@"
+      D9 0107                           # tag(263)
+         54                             # bytes(20)
+            495F947276749CE646F68AC8C248420045CB7B5E # contract address
+      C2                                # tag(2)
+         58 20                          # bytes(32)
+            42CDA393BBE6D079501B98CC9CCF1906901B10BF000000000000020000000001 # token id
+```
+
+* As a hex string:
+
+```
+A3010802183C03836140D9010754495F947276749CE646F68AC8C248420045CB7B5EC2582042CDA393BBE6D079501B98CC9CCF1906901B10BF000000000000020000000001
+```
+
+* As a UR **TODO**:
+
 
 ### References