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

摘要： 改进了Zhang等人的无证书签名方案，使新的无证书签名方案在签名和验证阶段只需两个双线性运算。新的无证书签名方案在随机预言模型下被证明是安全的。它的安全性建立在计算Diffie-Hellman问题的困难性之上。同时，基于新的无证书签名方案，还给出一个无证书盲签名方案。无证书盲签名方案的安全性归结到新的无证书签名方案的安全性。

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