An Efficient Group Signatures Based on Discrete Logarithm

A group signature scheme allows a group member to sign a message anonymously on behalf of the group. In case of a dispute, the group manager can reveal the actual identity of signer. To enhance the efficiency of group signature schemes, in this paper, we propose an efficient group signature scheme which adds some redundant bits to each divided message block, to avoid the conspiracy attack. In our scheme, the size of a signature is the same as that of an individual signature and the signature verification process is simplified by a group public key. The security of the proposed scheme is based on the difficulty of computing the discrete logarithm modulo for a composite number.