关键词: 群签名，前向安全，成员撤销，超前签名

Abstract: A group signature scheme equipped with multiple security strategy was proposed. This scheme has forward security which can minimize the damage caused by the exposure of any group membefs signing key, and does not affect to the past signatures generated by this member; meanwhile, ahead signature generated by a group member before the joining date can be prevented via this strategy. Moreover, this scheme supports the group member revocable function efficicntly, if a certain group member is cancelled from the group, he can sign a message on the behalf of the group no longer. There is traceability for signature, in the case of a dispute about a signature, GM can open the signature to determinate the identity of a signature, anyone besides GM can not open any signature. Furthermore, there is no requirement for time period limits like previous schemes in which it is necessary to setup system while all time periods are used out.

Key words: Group signature, Forward security, Member revocation, Ahead signature