W3C Credential Standard Leaves Issuer Trust to Verifiers

A digital identity credential can pass a signature check without proving its claim is true, leaving verifiers to decide whether they trust the issuer before relying on it.

A verifiable credential involves three roles: an issuer makes a claim, a holder presents the credential and a verifier evaluates it. A matching digital signature helps establish that a statement came from a key associated with the issuer and has not been altered. It does not, by itself, establish whether the issuer was entitled to make that particular claim.

The Verifiable Credentials Data Model v2.0 became a World Wide Web Consortium (W3C) Recommendation on May 15, 2025. It separates verification of an authentic, current issuer statement from validation of whether the claims meet a verifier’s requirements. The decision about which issuers to trust, and for which claims, rests with the verifier.

That distinction matters for identity systems built around credentials held in digital wallets. A system can check a signature correctly and still accept a claim from an issuer it should not rely on for that purpose. The verifier needs a basis for accepting the issuer’s authority as well as a way to check the credential itself.

Trust Begins With Issuance

U.S. identity proofing guidance includes mobile driver’s licenses among forms of digital evidence. The strength of such evidence depends on how rigorously it was issued, how confidently it can be validated and whether it can be linked to the person presenting it. A cryptographic check addresses only part of that assessment.

Consider a holder presenting a credential whose signature passes. The verifier still has to assess whether the claim meets its requirements and whether the evidence belongs to that holder. The signature does not answer either question on its own. Nor does it establish that every claim made with the same issuer key deserves the same level of trust.

Issuer trust therefore concerns the scope of a claim, not just the identity of a signing key. A verifier may recognize who issued a credential while still needing to decide whether to accept what it says. That judgment is part of using the credential, even when the cryptography works as intended.

Trust Can Change After Issuance

A signing key can also cease to be reliable. If an attacker compromises a key, use of that key may be indistinguishable from use by its authorized controller until the key is revoked. A signature check alone cannot resolve that problem: the attacker’s signature may pass the same check as an authorized one.

A credential’s status is a separate consideration. Revocation cancels its validity, while suspension temporarily prevents its acceptance. A verifier evaluating a credential needs to know whether a change in status affects its decision to rely on the claim. A signature made before that change does not remove the need for a current status check.

Status checks introduce a privacy concern. Looking up a unique status URL for each credential can expose when that credential is checked and which verifier checks it. The check helps a verifier avoid relying on a revoked or suspended credential, but its design also affects what can be learned about the holder’s use of it.

These are distinct checks. The signature concerns the statement and its key; the status concerns whether the credential remains acceptable; and the verifier’s rules determine whether the issuer’s claim serves the intended purpose. Passing one check does not settle the others.

A Registry Does Not Set Trust Rules

A blockchain can serve as a tamper-evident registry for parts of a credential system. Other publication methods can serve that role as well. A record that makes changes evident can help a verifier inspect information it needs, but the record cannot decide which issuers should be trusted to make which claims.

For a crypto identity project, putting registry information on a blockchain leaves the central trust decision with the party evaluating a credential. That party must still consider the issuer’s authority, the link between the evidence and its presenter, and whether a key or credential remains valid. The value of a signed claim depends on those decisions as well as on the signature.