Quasi-Efficient Revocation of Group Signatures
Giuseppe Ateniese, Dawn Xiaodong Song, Gene Tsudik · 2001
A group signature scheme allows any group member to sign on behalf of the group in an anonymous and unlinkable fashion. In the event of a dispute, a designated trusted entity can reveal the identity of the signer. Group signatures are claimed to have many useful applications such as voting and electronic cash. A number of group signature schemes have been proposed to-date. However, in order for the whole group signature concept to become practical and credible, the problem of secure and efficient group member revocation must be addressed. In this paper, we construct a new revocation method for group signatures based on the signature scheme by Ateniese et al. [ACJT]. This new method represents an advance in the state-of-the-art since the only revocation schemes proposed thus far are: 1) based on implicit revocation and the use of fixed time periods, or 2) require the signature size to be linear in terms of the number of revoked members. Our method, in contrast, requires no time periods and offers constant-length signatures.