What Are Verifiable Credentials?

VCs represent digital credentials that are cryptographically verifiable. This allows them to be kept on digital devices, enabling the use of cryptography to confirm their data and the identity of the issuer.

Using digital identity wallets, users can store and provide for verification their VCs representing:

ID card
Driving license
University degree
Vaccine proof
And more...

University Degree Credential
{
  "@context": [
    "https://www.w3.org/2018/credentials/v1.1"
  ],
  "type": ["VerifiableCredential", "UniversityDegreeCredential"],
  "id": "urn:credential:123456789-1010",
  "issuer": "did:web:roma-university.com",
  "issuanceDate": "2023-05-15T10:20:30Z",
  "credentialSubject": {
    "id": "did:example:123456789abcdefghi",
    "studentIdentifier": "123456789",
    "name": "Marcus Tullius",
    "dateOfBirth": "1993-03-31",
    "degreeEarned": "Bachelor of Arts in Philosophy",
    "issueDate": "2023-05-15",
    "universityName": "University of Rome",
    "gender": "Male"
  },
  "credentialStatus": {
    "id": "https://roma-university.com/vcs/credential/status/33",
    "type": "CredentialStatusList2023"
  },
  "proof": {
    "type": "Ed25519Signature2020",
    "created": "2023-05-15T10:20:30Z",
    "proofPurpose": "assertionMethod",
    "verificationMethod": "https://roma-university.com/keys/9",
    "proofValue": "z3ht4KPvnzDcUZKL5mY6PvZioQfgsC7z2nk2G8QJ3R8m5NzPF9t5JH8kzZ9RfzT5pX3z6rL7v89mp9yV7sN6xjg9Q"
  }
}

Verifiable Credential Example

To the left you can see a verifiable credential example for a university degree. It is prepared according to the W3C VC Data Model v1.1.

The type of a credential can help ascertain its relevance for certain situations. For example, a credential with the type DriverLicense is suitable for verifying driving privileges but may not be relevant for academic verification purposes.

The issuer indicates the entity that issued the credential. This should be a URI or an object that includes an 'id' attribute. While the URI or 'id' could be a Decentralized Identifier (DID), it is not a strict requirement.

The subject refers to the entity (such as an individual or organization) that the credential information pertains to. The credentialSubject encompasses one or more attributes linked to the credential's user. Usually, but not necessarily, a subject identifier is part of this object. Although the id might be a Decentralized Identifier (DID), it is not obligatory. There can be multiple subjects within the credentialSubject (for instance, in the case of a car insurance credential).

The proof refers to one or several cryptographic proofs, which can be structured as either an object or an array, utilized to identify any alterations and ascertain the origin of a credential or presentation.

How Verifiable Credentials Work