Efficient group signature with forward secure revocation

Forward secure revocation for group signature allows a revoked group member to preserve the anonymity of its signatures generated before the revocation. Most of the existing schemes of this type either have the signing or verifying complexity linear to the group size or the number of revoked members, or require the updates of signing key or public key once revocation occurs. Recently, an outstanding improvement has been made in Nakanishi et al.'s proposal [15]. However, the size of public key in their scheme is linear to the group size. In this paper, we propose a new forward secure revocable group signature scheme satisfying 1) constant signing and verifying complexity, 2) constant size in signature, public key and signing key, 3) no updates of public key or signing key are required when member joining or delete occurs. © 2009 Springer-Verlag Berlin Heidelberg.