根据RSA数字签名、GQ数字签名和IR前向数字签名的基本思想,提出一种基于前向安全的组签名体制.在这种签名体制中,组内所有成员共用惟一的一个公钥,而密钥服务器为组内每个成员分配一个能产生私人密钥的“种子”;在有效时间段,组内成员运用私人密钥产生算法或更新算法,实现自己私人密钥的产生或更新.通过对签名体制的性能分析,可以确定:对于一个有n个成员参加的组通信,如果采用此签名体制,那么,即使有n-1个组内成员“变节”,对于剩余的惟一一个成员来讲系统也是安全的.
Based on the basic theories of RSA signature, GQ signature, and IR forward secure signature, a group signature scheme with forward security is presented. In this signature scheme, the key server only generates one public key for all members of group and all members share this public key. At the same time, the key server also generates the secret key "seeds" for each member, thus, each member can only get one secret key "seed". During each time period, each member of group can generate or update his own secret key by using the secret key generation algorithm or the secret key update algorithm. By analyzing the performance of the digital signature, a conclusion may be drawn. It can be described as follows: In a group communication that includes n members, if the digital signature is adopted, and even (n- 1) members corrupt, the only one legal member is still secure under such attacks.