关键词: 无证书密码系统, 盲签名, 双线性映射, 计算Diffie-Hellman问题, 随机预言器

Abstract: An improved certificateless signature scheme，based on a previous construction of Zhang et al，is advanced.The new certificateless signature scheme is computationally efficient in that it just needs two pairing operations in its signing and verification phases.It is proved secure in the random oracle models with the assumption that the computational Diffie-Hellman problem is infeasible.At the same time，a blind signature scheme is presented，which is based on the new certificateless signature scheme.Therefore，the security of blind signature scheme depends on certificateless signature scheme.

Key words: certificateless cryptography, blind signature, bilinear pairing, computational Diffie-Hellman problem, random oracle