Verifiable Accreditations

Verifiable Accreditations are credentials that are issued from one organisation to another organisation to "accredit" that organisation to perform a particular action. These types of credentials are stored directly on-ledger as DID-Linked Resources, meaning that they are persistent, sequentially versioned and highly available.

There are two types of Verifiable Accreditation:

Type	Description
Verifiable Accreditation to Accredit	This Credential verifies that an organisation has the permissions needed to accredit other organisations for issuing a particular type of Verifiable Accredittion.
Verifiable Accreditation to Attest	This Credential verifies that an organisation has the permissions needed to issue Verifiable Credentials, defined by a particular schema.

For a trusted ecosystem, these attestations are required to trace the legitimacy of a credential issuer to a root-of-trust.

Verifiable Accreditation Schema

In order to ensure consistency and interoperability within a trusted ecosystem, Trusted Accreditation Organisations (TAOs) should define schemas for the Verifiable Accreditations for their particular ecosystem. They may also reuse existing schemas that have been created for equivalent ecosystems.

Verifiable Accreditation Schema Example

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "Verifiable Accreditation Record",
  "description": "Schema of an Verifiable Accreditation",
  "type": "object",
  "allOf": [
    {
      "properties": {
        "credentialSubject": {
          "description": "Defines additional information about the subject that is described by the Verifiable Accreditation",
          "type": "object",
          "properties": {
            "id": {
              "description": "Defines a unique identifier of the Verifiable Attestation",
              "type": "string",
              "format": "uri"
            },
            "reservedAttributeId": {
              "description": "Defines the attributeId this Verifiable Accreditation has been created for",
              "type": "string"
            },
            "accreditedFor": {
              "description": "Defines a list of claims that define/determine the authorisation of an Issuer to issue certain types of VCs",
              "type": "array",
              "items": {
                "type": "object",
                "properties": {
                  "schemaId": {
                    "description": "Schema, registered as a DID-Linked Resource, which the accredited organisation is allowed to issue, as per their accreditation",
                    "type": "string",
                    "format": "uri"
                  },
                  "types": {
                    "type": "array",
                    "items": {
                      "type": "string"
                    }
                  },
                  "limitJurisdiction": {
                    "anyOf": [
                      {
                        "description": "Defines the jurisdiction for which the accreditation is valid",
                        "type": "string",
                        "format": "uri"
                      },
                      {
                        "type": "array",
                        "description": "Defines the jurisdictions for which the accreditation is valid",
                        "items": {
                          "type": "string",
                          "format": "uri"
                        }
                      }
                    ]
                  }
                },
                "required": ["schemaId", "types", "limitJurisdiction"]
              }
            }
          },
          "required": ["id", "reservedAttributeId", "accreditedFor"]
        },
        "credentialStatus": {
          "description": "Defines revocation details for the issued credential. Further redefined by type extension",
          "type": "object",
          "properties": {
            "id": {
              "description": "Exact identity for the credential status",
              "type": "string",
              "format": "uri"
            },
            "type": {
              "description": "Defines the revocation status type",
              "type": "string",
              "const": "AccreditationEntry"
            }
          },
          "required": ["id", "type"]
        }
      },
      "required": [
        "expirationDate",
        "credentialSubject",
        "credentialStatus",
        "termsOfUse"
      ]
    }
  ]
}

Verifiable Accreditation Examples

Notably, Verifiable Accreditations are credentials that are issued to organisational DIDs on cheqd. In each Verifiable Accreditation, there is also a reservedAttributeId that corresponds to the resourceId of the Accreditation as a DID-Linked Resource.

Verifiable Accreditation to Accredit Example

{
  "@context": ["https://www.w3.org/2018/credentials/v1"],
  "id": "urn:uuid:8568b525-a24e-4bc0-9d97-6a8459ec0130",
  "type": [
    "VerifiableCredential",
    "VerifiableAttestation",
    "VerifiableAccreditation",
    "VerifiableAccreditationToAccredit"
  ],
  "issuer": "did:cheqd:testnet:098c4f66-b461-4037-9cf0-c5db75b270c6",
  "issuanceDate": "2021-11-01T00:00:00Z",
  "validFrom": "2021-11-01T00:00:00Z",
  "expirationDate": "2025-06-22T14:11:44Z",
  "issued": "2020-06-22T14:11:44Z",
  "credentialSubject": {
    "id": "did:cheqd:testnet:e21b63d1-a771-4eb9-9452-869cd30fd622",
    "reservedAttributeId": "05afe541-77dd-4eda-9e01-2258c74b291b",
    "accreditedFor": [
      {
        "schemaId": "did:cheqd:testnet:098c4f66-b461-4037-9cf0-c5db75b270c6/resources/83eb0ed8-37d1-4ba6-9e0b-40d60676d4aa",
        "types": [
          "VerifiableCredential",
          "VerifiableAttestation",
          "DiplomaCredential"
        ]
      }
    ]
  },
  "credentialStatus": {
    "id": "did:cheqd:testnet:098c4f66-b461-4037-9cf0-c5db75b270c6?resourceName=accreditationStatus&resourceType=StatusList2021Revocation",
    "type": "StatusList2021Revocation"
  },
  "termsOfUse": [
    {
      "id": "did:cheqd:testnet:098c4f66-b461-4037-9cf0-c5db75b270c6/resources/ab670b62-469c-4901-af7e-0ce94b5cccea",
      "type": "IssuanceCertificate"
    }
  ],
  "credentialSchema": [
    {
      "id": "did:cheqd:testnet:098c4f66-b461-4037-9cf0-c5db75b270c6/resources/83eb0ed8-37d1-4ba6-9e0b-40d60676d4aa",
      "type": "FullJsonSchemaValidator2021"
    }
  ]
}

Verifiable Accreditation to Attest Example

{
  "@context": ["https://www.w3.org/2018/credentials/v1"],
  "id": "urn:uuid:8568b525-a24e-4bc0-9d97-6a8459ec0130",
  "type": [
    "VerifiableCredential",
    "VerifiableAttestation",
    "VerifiableAccreditation",
    "VerifiableAccreditationToAttest"
  ],
  "issuer": "did:cheqd:testnet:098c4f66-b461-4037-9cf0-c5db75b270c6",
  "issuanceDate": "2021-11-01T00:00:00Z",
  "validFrom": "2021-11-01T00:00:00Z",
  "expirationDate": "2025-06-22T14:11:44Z",
  "issued": "2020-06-22T14:11:44Z",
  "credentialSubject": {
    "id": "did:cheqd:testnet:e21b63d1-a771-4eb9-9452-869cd30fd622",
    "reservedAttributeId": "15b49499-2a36-4c73-9f5b-7409b44ce7a3",
    "accreditedFor": [
      {
        "schemaId": "did:cheqd:testnet:098c4f66-b461-4037-9cf0-c5db75b270c6/resources/da4159f1-ff50-4a7c-b0cb-40d3a1f71003a",
        "types": [
          "VerifiableCredential",
          "VerifiableAttestation",
          "DiplomaCredential"
        ]
    ]
  },
  "credentialStatus": {
    "id": "did:cheqd:testnet:098c4f66-b461-4037-9cf0-c5db75b270c6?resourceName=accreditationStatusToAttest&resourceType=StatusList2021Revocation",
    "type": "EbsiAccreditationEntry"
  },
  "termsOfUse": [
    {
      "id": "https://api-test.ebsi.eu/trusted-issuers-registry/../..xyz",
      "type": "IssuanceCertificate"
    }
  ],
  "credentialSchema": [
    {
      "id": "did:cheqd:testnet:098c4f66-b461-4037-9cf0-c5db75b270c6/resources/da4159f1-ff50-4a7c-b0cb-40d3a1f71003a",
      "type": "FullJsonSchemaValidator2021"
    }
  ]
}

Verifiable Accreditations as DID-Linked Resources

Storing Verifiable Accreditations as DID-Linked Resources enables each accreditation to be individually resolvable using a DID URL. It also enables Accreditations to be "chained" to a DID, allowing the traversal of the Accreditation to the root of trust.

The diagram below shows how DID-Linked Resources can be applied to the trust hierarchy to enable DID resolvable Verifiable Accreditations: