SD-JWT

SD-JWT is an IETF credential format used in the EUDI Wallet, letting holders selectively disclose individual attributes from a signed token.

SD-JWT (Selective Disclosure JWT) is an IETF format for digital credentials built on JSON Web Token (JWT), in which each attribute value is combined with a random salt and hashed separately into a signed JWT. The holder receives the signed token plus the raw attribute values and salts, and can prove any subset to a verifier - the basis of selective disclosure. Because the issuer's signature is reused across presentations, SD-JWT does not provide unlinkability: a verifier (or colluding verifiers) can in principle correlate presentations of the same credential, unlike zero-knowledge proof schemes such as BBS+.

SD-JWT VC is one of the two credential formats prescribed for the EUDI Wallet (next to mdoc), typically used for online/remote presentations via OpenID4VP (OpenID4VC).