ID-Based Deniable Threshold Ring Authentication

Deniable threshold ring authentication allows at least t members of a group participants to authenticate a message m without revealing which t members have generated the authenticator, and the verifier cannot convince any third party the message m is authenticated. It can be applied in anonymous and privacy communication scenarios. In this paper, we present a non-interactive identity-based deniable threshold ring authentication scheme. Our scheme is provably secure in the random oracle model under the bilinear Diffie-Hellman assumption. To the best of our knowledge, our scheme is the first identity based deniable threshold ring authentication scheme. Our scheme is very efficient since it only requires one pairing operation in authentication phase and one pairing operation in verification phase regardless of the number of the ring.