A new ID-based ring signature scheme with constant-size signature

The ring signature can guarantee the signer´s anonymity. Most proposed ring signature schemes have the problem that the size of ring signature depends linearly on the ring size. Some authors have studied the constant-size ring signature to solve the problem. This paper shows that an identitybased 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. A new scheme with constant-size signature length is proposed based on a new secure accumulator from bilinear pairings.