Working definition

A digital identity credential is a machine-processable credential containing claims about, or bound to, an identifiable or pseudonymous subject. It is issued by an authority and used by another party to inform a trust, eligibility, or authorization decision.

The subject is often a person, but may also be an organization acting through an authorized representative. The credential need not reveal a civil identity: a pseudonymous credential or a selectively disclosed age assertion can still participate in digital identity when its claims are bound to the same subject or holder.

This definition is intentionally narrower than every technical use of the word credential. Passwords, API keys, operating-system security contexts, and session tokens are often called credentials, but they are not digital identity credentials in the sense used here.

What they can assert

Digital identity is more than a name or government identifier. A credential may establish core identity attributes or associate qualifications, roles, and rights with a subject.

Category Typical claims Examples
Identity-establishing Name, date of birth, nationality, portrait, identifier Person identification data, passport-derived credential
Qualification Education, training, professional competence Degree, diploma, professional certification
Licence Regulated status and permitted activity Driving licence, medical licence
Affiliation and role Membership, employment, organizational role Employee credential, association membership
Authorization and entitlement Permission, eligibility, access right Practice authorization, benefit entitlement
Derived or minimal assertion A fact derived from underlying attributes Over 18, resident of a jurisdiction, licensed to drive

A professional licence is therefore a digital identity credential under this definition. Its primary claim concerns authorization or professional status, but that claim is bound to a particular subject.

Roles and lifecycle

Most credential systems distinguish several roles:

  1. The issuer creates the credential and makes claims about the subject.
  2. The holder controls or stores the credential and may present it.
  3. The subject is the entity described by the claims. The subject and holder are often, but not always, the same.
  4. The verifier receives claims or a presentation and evaluates them for a stated purpose.

The lifecycle can include issuance, storage, presentation, verification, status checking, renewal, suspension, and revocation. Exchange protocols coordinate some of these steps, but a protocol message is not itself necessarily a credential.

Representation is not meaning

The same real-world claim can be represented through different credential families and security mechanisms. Examples include W3C Verifiable Credentials, SD-JWT VC, ISO mdoc, and AnonCreds. They differ in data model, encoding, proof construction, disclosure behavior, and ecosystem rules.

These dimensions must be kept separate:

  • credential family defines the base model;
  • profile adds versioned domain or ecosystem constraints;
  • serialization describes the concrete encoding;
  • security envelope carries or embeds integrity protection;
  • presentation mechanism determines how claims are disclosed;
  • exchange protocol coordinates issuance or presentation.

Calling an artifact a verifiable credential, JWT, or mobile document does not establish that it is authentic, trusted, current, privacy-preserving, or suitable for a particular purpose.

Trust is evaluated, not assumed

Useful analysis separates observable structure from assurance. Depending on the operation and available evidence, a verifier may need to determine:

  • whether the artifact can be decoded and is structurally well formed;
  • whether its cryptographic proof is valid;
  • whether the verification key was authorized by the issuer;
  • whether the issuer is trusted to make the specific claim;
  • whether the credential is expired, suspended, or revoked;
  • whether the presenter is bound to the credential and current transaction;
  • whether disclosure is proportionate to the verifier’s purpose; and
  • whether the verified evidence satisfies an explicit policy.

No single successful check establishes all of these properties. In particular, a valid signature does not by itself establish issuer authority or fitness for purpose.

Privacy considerations

Digital identity credentials can disclose more information than a verifier needs. Privacy-oriented systems may support selective disclosure, derived predicates, pseudonymous identifiers, unlinkable presentations, or zero-knowledge proofs. These mechanisms have distinct guarantees and must not be treated as interchangeable.

Even when claim values are hidden, stable identifiers, status lookups, issuer metadata, and repeated presentation patterns may enable correlation. Privacy analysis therefore covers the complete presentation and verification process, not only the credential payload.

Scope boundary

Within Proofet research, digital identity credentials include civil identity, qualifications, licences, affiliations, roles, authorizations, entitlements, and privacy-preserving assertions bound to an identifiable or pseudonymous subject.

The primary scope excludes:

  • passwords, authentication secrets, and ordinary session tokens;
  • transferable bearer instruments, digital cash, and general-purpose tickets;
  • product provenance credentials and device attestations unrelated to a subject’s identity;
  • protocol requests and responses that contain no credential; and
  • arbitrary signed documents without a credential model or trust purpose.

These neighboring artifacts may still matter to the wider Proofet Atlas, but they are not treated as digital identity credentials merely because they are digital, signed, or called credentials by a particular platform.

Reference points

This working definition synthesizes concepts used across several bodies of work rather than adopting the broadest possible use of credential:

Proofet Atlas 0.1.0 records the classifications and assurance boundaries needed to compare these families without implying that one terminology or representation applies universally.