Digital credentials

A digital credential is a set of claims about a holder, signed by an issuer, stored in a wallet, and verifiable by anyone without contacting the issuer.

What one contains

Claims	The statements themselves — date of birth, licence class, qualification
Issuer	Who signed it, and the key that proves it
Holder binding	A key held by the wallet, so a stolen credential cannot be replayed
Validity	When it was issued and when it stops being accepted

Why the signature is enough

The verifier checks that the signature is intact and that the issuer's certificate chains to something it trusts. No lookup, no shared database, no availability dependency on the issuer.

Holder binding

Without it, a credential would be a bearer token: whoever copied the file could present it. The wallet holds a private key that the credential commits to, and presenting requires a fresh signature with that key — tied to the specific verifier and request, so a captured presentation cannot be reused elsewhere.