Abstract: This paper proposes a secure and efficiency group signature scheme from bilinear pairings in certificateless cryptography.It not only enjoys all the security requirements of a group signature，but also is a dynamic group signature scheme that allows users to join or leave the group freely without updating the group public key and other group members’ private signing key.At the same time，the length of the signature is independent of the numbers of the group members.The security of our scheme is based on the fact that computational Differ-Hellman problem is hard.

Key words: group signature, certificateless cryptography, bilinear pairing, random oracle, computational Differ-Hellman problem

摘要： 提出一个安全有效的无证书群签名方案。该方案满足群签名的各种安全性要求，还允许用户动态地加入与离开且不需更新群公钥和其他群成员的签名私钥。群签名的长度不依赖于群成员的数目。它的安全性建立在计算Differ-Hellman问题的困难性之上。

关键词: 群签名, 无证书密码体制, 双线性映射, 随机预言器, 计算Differ-Hellman问题