README.md

claim-schema-vocab

Repository for credential schema definition and vocabularies.

Repository: https://github.com/iden3/claim-schema-vocab

General description:

This repository contains JSON-LD and JSON schemas for Iden3 Credentials. At the current stage, the Iden3Credential data model utilizes W3C Verifiable Credential Model but has some additional defined fields. In the future, it can be fully adapted to the W3C Verifiable Credential standard.

The repository structure is following:

1. credentials

   The folder contains vocabulary definitions for common claim structure, authentication claim, KYC-specific vocabulary, and serialization vocabulary. For example, field countryCode is defined in kyc.md vocabulary file and resolved to link https://github.com/iden3/claim-schema-vocab/blob/main/credentials/kyc.md#countrycode that gives information about the field: description, type, example.

   • Example of Iden3Credential:

     {
         "id": "8af6c48a-547a-4af6-a1c6-b4c049691cd2",
         "@context": [
             "https://raw.githubusercontent.com/iden3/claim-schema-vocab/main/schemas/json-ld/iden3credential.json-ld",
             "https://raw.githubusercontent.com/iden3/claim-schema-vocab/main/schemas/json-ld/kyc.json-ld"
         ],
         "@type": [
             "Iden3Credential"
         ],
         "expiration": "2361-03-21T21:14:48+02:00",
         "updatable": false,
         "version": 0,
         "rev_nonce": 10525844421148161795,
         "credentialSubject": {
             "birthdayDay": 24,
             "birthdayMonth": 4,
             "birthdayYear": 1995,
             "documentType": 1,
             "id": "117C9YUVPqEcAAAVMWvew1qc5cogC7nVTU4swnkAcB",
             "type": "KYCAgeCredential"
         },
         "credentialStatus": {
             "id": "http://localhost:8001/api/v1/identities/11AqUpgUacPUy6BwZeDW2kJYBJSEzBQKCLvEtwa2Rs/claims/revocation/status/10525844421148161795",
             "type": "SparseMetkleTreeProof"
         },
         "credentialSchema": {
             "@id": "https://raw.githubusercontent.com/iden3/claim-schema-vocab/main/schemas/json/KYCAgeCredential.json",
             "type": "JsonSchemaValidator2018"
         },
         "proof": [
             {
                 "@type": "BJJSignature2021",
                 "created": 1638468318,
                 "issuer_mtp": {
                     "@type": "Iden3SparseMerkleProof",
                     "state": {
                         "claims_tree_root": "c71299a362950a08a900bcb260cbdac97378ed611d5f9348c58e06ac6875bd2a",
                         "value": "d66f2b1f07d8a9bfaf570d8d746dfb11bce9f33fdabcacf8d46e5cf787e7e22b"
                     },
                     "mtp": {
                         "@type": "SparseMerkleProof",
                         "existence": true,
                         "siblings": []
                     },
                     "issuer": "11AqUpgUacPUy6BwZeDW2kJYBJSEzBQKCLvEtwa2Rs"
                 },
                 "creator": "11AqUpgUacPUy6BwZeDW2kJYBJSEzBQKCLvEtwa2Rs",
                 "verification_method": "ba483cc1ffa1b01750db0de4c560f13146c82e281d6d7bdf05484987a87aea23",
                 "proof_value": "26674458c9fb7dea57506bca887f12372f062c797f76643c66b81a1d73784218dbd914a9c630fdd677da147eeba7aa903905e81145ecb8d7e0e54296e33c3304",
                 "proof_purpose": "Authentication"
             },
             {
                 "@type": "Iden3SparseMerkleProof",
                 "state": {
                     "tx_id": "0xd85a6a72dd3d04a00d0e9cd8bbaac555820d60a5f1024d1c9c6c2c1390376cea",
                     "block_timestamp": 1638468530,
                     "block_number": 11539897,
                     "claims_tree_root": "8ef71c04cf00fecb0f0ab455088862198e8a66fd162bbb52c4dbd9d4de994929",
                     "revocation_tree_root": "0000000000000000000000000000000000000000000000000000000000000000",
                     "value": "b9488bc7a0d9bbe1ac74d5def9a9a7fc6bdadfb2269245ae0d2fd817bc0dc124"
                 },
                 "mtp": {
                     "@type": "SparseMerkleProof",
                     "existence": true,
                     "siblings": [
                         "19331884062013742676999221288855742156448004856978252244854118388210484187847",
                         "2250684463907041370291277709224474920208296274915622528394669370926641373444"
                     ]
                 },
                 "issuer": "11AqUpgUacPUy6BwZeDW2kJYBJSEzBQKCLvEtwa2Rs"
             }
         ]
     }

2. proofs

   This folder defines vocabularies for different proof types that can be used for Iden3Credentials. It defines vocabulary for Iden3SparseMerkleTreeProof

   • Example of valid Iden3SparseMerkleTreeProof

     {
                 "@type": "Iden3SparseMerkleProof",
                 "state": {
                     "tx_id": "0xd85a6a72dd3d04a00d0e9cd8bbaac555820d60a5f1024d1c9c6c2c1390376cea",
                     "block_timestamp": 1638468530,
                     "block_number": 11539897,
                     "claims_tree_root": "8ef71c04cf00fecb0f0ab455088862198e8a66fd162bbb52c4dbd9d4de994929",
                     "revocation_tree_root": "0000000000000000000000000000000000000000000000000000000000000000",
                     "value": "b9488bc7a0d9bbe1ac74d5def9a9a7fc6bdadfb2269245ae0d2fd817bc0dc124"
                 },
                 "mtp": {
                     "@type": "SparseMerkleProof",
                     "existence": true,
                     "siblings": [
                         "19331884062013742676999221288855742156448004856978252244854118388210484187847",
                         "2250684463907041370291277709224474920208296274915622528394669370926641373444"
                     ]
                 },
                 "issuer": "11AqUpgUacPUy6BwZeDW2kJYBJSEzBQKCLvEtwa2Rs"
             }

3. schemas

   • JSON

     JSON schemas define the validation rules for claim content (using JSON standard) and also specifies the order of fields to fill claim slots (according to claim specification). For that Index and Value custom fields are used. Implementors must use these fields.

   • JSON-LD

     JSON-LD schema allows to provide both - association with data vocabulary and claim slot specification. It doesn't confront with JSON, but extending the possibilities. This create an opportunity to exchange documents in machine readable format with document normalization and linked data structures and human readable by providing needed vocabulary.

     For claim slots preparation several serialization types are used:

     IndexDataSlotA, IndexDataSlotB, ValueDataSlotA, ValueDataSlotB

     If specific can't be specified next types must be used: Index, Value