A New Type of Group Signature Scheme

On the basis of BB short signature scheme, this paper derives a new signature scheme, from which a new kind of group signature scheme is constructed. The security of the new group signature scheme is based on the q- SDH assumption and the decisional Diffie-Hellman assumption in the random oracle model. The length of the new group signature is a little longer than that of BBS short group signature. However, in the group signature scheme, giving certificates and private keys to group members do not need any third trusted party, while in BBS short group signature scheme it does need.