An efficient scheme for anonymous authentication using identity based group signature

Group signature allows any valid group member to sign any number of messages on behalf of the group without revealing the member identity. The group manager can reveal the identity of the signer in the case of a dispute. Most of the group signatures are based on traditional cryptography, such as RSA, ECC and discrete logarithm. But these schemes would be easily broken if quantum computers emerge. In this paper, we propose a new identity based group signature. Our signature scheme is based on bilinear maps. This identity based scheme has the security properties of group signatures. In this scheme the size of the group pubic key and the length of signatures are independent on the size of the group. This scheme is well suited for large groups. Using the same key pair the group member can sign many messages.