ID-Based Deniable Ring Signature with Constant-Size Signature

The ring signature can guarantee the signer’s anonymity. Most proposed ring signature schemes have two problems: One is that the size of ring signature depends linearly on the ring size, and the other is that the signer can shift the blame to victims because of the anonymity. Some authors have studied the constant-size ring signature and deniable ring signature to solve these two problems. This paper shows that an identity-based ring signature scheme with constant size has some security problems by using an insecure accumulator and its verification process does not include the message m. Then we combine the concepts of “constant-size” and “deniable” to form an id-based deniable ring signature with constant-size signature. The new scheme with constant-size signature length is proposed based on an improved accumulator from bilinear pairings and it solves the problem of anonymity abuse.