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

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