Revoking Direct Anonymous Attestation credentials by updating group public/private key pair and only updating valid credentials

摘要

Direct Anonymous Attestation (DAA) involves a Signer (B11/B) using a credential supplied by an Issuer (B10/B) to anonymously prove to a Verifier (B12/B), on the basis of a public key of the Issuer, the Issuer's attestation to the Signer's membership of a particular group. To facilitate membership revocation, the Issuer updates (B62/B) the public key at intervals, and also effects a complementary updating (B63/B) to the Signer's credential unless the Signer has ceased to be a legitimate group member. A non-updated credential is inadequate to enable the Signer (B11/B) to prove its Issuer attested group membership to a Verifier (B12/B) on the basis of the updated Issuer public key. The system can be used with Trusted Platform Modules (TPM).