Verifiable credentials scheme for education

Terminology

vc — Verifiable Credential, according to vc data model https://www.w3.org/TR/vc-data-model/

credential — A set of one or more claims made by an issuer. A verifiable credential is a tamper-evident credential that has authorship that can be cryptographically verified. Verifiable credentials can be used to build verifiable presentations, which can also be cryptographically verified. The claims in a credential can be about different subjects.

All credentials have the next fields according to a scheme

claim — all data + metadata (An assertion made about a subject.))
proof — signature by gov't
issuer — id of the issuer organization (URI, DID, JWK or object with ID)

W3C Task Force: https://github.com/w3c-ccg/vc-ed/

did 101: https://w3c-ccg.github.io/did-method-v1/

Verifiable credentials lifecycle

Interoperability: https://www.youtube.com/watch?v=mXLy2Rof_iA

There are 3 main roles in VC lifecycle: Issuer, Holder and Verifier.

Issuer receiving the credentials request from holder's wallet application, and answers with a signed Verifiable Credential.
Holder then can generate a verifiable presentation to share required data of VC with the verifier.
Verifier

Diagram: https://www.w3.org/TR/vc-use-cases/#user-tasks

https://www.w3.org/TR/vc-use-cases/#terminology

HTTP API: https://w3c-ccg.github.io/vc-api/#architecture-overview

Verifiable Credentials status

For invalidating credentials the VC status list concept can be used

https://w3c-ccg.github.io/vc-status-list-2021/

The support for issuing credentials compliant with VC Status List 2021 was added to sign and verify services in https://github.com/digitalcredentials/sign-and-verify-core/pull/18

DID methods

The most popular:

did:web https://w3c-ccg.github.io/did-method-web/#did-method-operations
did:key https://w3c-ccg.github.io/did-method-key/
Bitcoin, Ethereum, etc.

To register DID, we need a pair of private/public jwk keys.

DID registration specification: https://identity.foundation/did-registration/#abstract

Testing Tool for DID and VC: https://github.com/transmute-industries/api.did.actor

VC Extensions

OpenBadges3.0 specific: https://imsglobal.github.io/openbadges-specification/ob_v3p0.html

There is a custom data model that maps to VC data model. For example, instead of the claim credentialSubject is presented.

"credentialSubject": {
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
    "type": ["AchievementSubject"],
    "achievement": {}
  },
  "credentialSchema": [{
    "id": "https://imsum2.herokuapp.com/jsonschema?classId=org.1edtech.ob.v3p0.achievementcredential.class",
    "type": "JsonSchemaValidator2019"
  }]