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Version: 5.x

Document Status

TradeTrust checks that the document has been issued and that it's issuance status is in good standing (for instance, that it hasn't been revoked).

As of today, TradeTrust supports two ways to verify documents:

  • Transferable: Uses Ethereum smart contracts through a Token Registry.
  • Non-Transferable: Uses BitString CredentialStatus (specifically, BitStringStatusList2021).
  • None

Transferable​

Ethereum Smart Contracts - Token Registry​

The Token Registry smart contract is deployed by individual issuers, such as land title registries (for title deeds) or shipping lines (for bills of lading), to mint transferable records. It stores document ownership by mapping document IDs (also known as token IDs) to title escrow contract addresses.

The Token Registry tracks the ownership state of transferable records using a mapping from document ID to smart contract address. Each document ID (token ID) is the hash of the Verifiable Credential (VC) ID of the individual TradeTrust document, and the corresponding smart contract address represents a title escrow smart contract.

Sample TransferableRecords credentialStatus within a W3C VC document:

  "credentialStatus": {
    "type": "TransferableRecords",
    "tokenNetwork": {
      "chain": "ETH",
      "chainId": "1337"
    },
    "tokenRegistry": "0x9Eb613a88534E2939518f4ffBFE65F5969b491FF",
    "tokenId": "1683a00c42430b72c42a8013e6695b839ab7f7b06db69835b974392613826bd2"
  }

Issuance and verification process​

  1. Create a issuer key pair using did:web.

  2. Deploys a Token Registry contract on a supported network and obtain its address. (This is a one-time action)

  3. Bind the registry's identity to the issuer using did:web.

  4. Prepare the raw Verifiable Credential (VC) payload with a TransferableRecords credentialStatus object.

  5. Sign the VC payload to generate the VC document's id and tokenId.

  6. Issue the document by minting an NFT with the generated tokenId, specifying its holder and beneficiary.

  7. During verification, the tokenId is checked against the tokenRegistry address to verify its validity.

For more information, refer to the Tutorial - Creator

Non-Transferable​

BitString CredentialStatus - BitStringStatusList2021​

The BitStringStatusList2021 credential status uses a compact, off-chain structure to manage document status efficiently. It relies on a bitstring to represent the state of each document, ensures scalability and reduces on-chain storage costs.

Sample BitString credentialStatus within a W3C VC document:

  "credentialStatus": {
    "id": 'https://trustvc.github.io/did/credentials/statuslist/1#1',
    "statusListCredential": 'https://trustvc.github.io/did/credentials/statuslist/1',
    "statusListIndex": '1',
    "statusPurpose": 'revocation',
    "type": 'StatusList2021Entry'
  },

Sample Bitstring Status List. Example hosted on GitHub Pages.

{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://w3id.org/security/bbs/v1",
    "https://w3id.org/vc/status-list/2021/v1"
  ],
  "id": "https://trustvc.github.io/did/credentials/statuslist/1",
  "type": [
    "VerifiableCredential",
    "StatusList2021Credential"
  ],
  "issuer": "did:web:trustvc.github.io:did:1",
  "issuanceDate": "2024-10-02T08:49:52.749Z",
  "validFrom": "2024-10-02T08:49:52.435Z",
  "credentialSubject": {
    "id": "https://trustvc.github.io/did/credentials/statuslist/1#list",
    "type": "StatusList2021",
    "statusPurpose": "revocation",
    "encodedList": "H4sIAAAAAAAAA-3BMQEAAAwCoH32b7RoxvAB8gcAAAAAAAAAAAAAAAAAAACMFVeOQ9sAQAAA"
  },
  "proof": {
    "type": "BbsBlsSignature2020",
    "created": "2024-10-02T08:49:54Z",
    "proofPurpose": "assertionMethod",
    "proofValue": "ohxpxgF6BUhGkSLBSGknWAVgx2flaQ4Hvl8MpD+tvVVEESXlQf0PbefZgg0Kj4+AUQS9wzJ/DjfbmkEkqiQU4RSKC82uPmoL5K7QWQRL4G8tymiY5ITLuRtYeACoiZz/dhF1wxxyJArGEI8ZWGCGNw==",
    "verificationMethod": "did:web:trustvc.github.io:did:1#keys-1"
  }
}

Issuance and verification process​

  1. A BitString Status List is generated for a batch of documents, where each bit represents the status of a document.

  2. Prepare the raw Verifiable Credential (VC) payload with StatusList2021Entry credentialStatus object, which includes the statusListIndex.

  3. The BitString Status List can be updated to modify the status of any index. After updating, the list is signed and rehosted.

  4. Status verification involves:

    • Fetching the bitstring list associated to the document id.
    • Checking the bit corresponding to the document’s statusListIndex.

Without any Document Status​

When no document status is explicitly provided, the document's validity is determined based on its document integrity. This implies that the document may be perpetually active, without an explicit expiry date.

Issuance and verification process​

  1. No credentialStatus required, therefore, no additional issuance steps are necessary.

  2. The verification process performs the same integrity check as for standard document integrity verification.