摘要： 对李继国等人提出的基于身份的高效签名方案(计算机学报，2009年第11期)进行分析，以一个具体的攻击方法，证明任何攻击者都可以伪造任意消息关于任意身份的有效签名，因此方案不满足存在不可伪造性。通过将原方案中签名的一个分量值固定，并将其作为用户的公钥，使方案在保证效率的同时，满足存在不可伪造性。

关键词: 密码学, 基于身份的签名方案, 数字签名, 双线性对, 密码分析

Abstract: This paper concludes that the efficient identity-based signature scheme proposed by Li Jiguo et al is insecure, and gives an attack method, which shows that any attacker can forge a valid signature on any message with respect to any identity. Therefore, Li Jiguo’s scheme does not satisfy existential unforgeability. By making a component of a signature as user’s public key, an improved scheme is proposed, which does not reduce the efficiency of Li Jiguo et al’s scheme while satisfying the existential unforgeability.

Key words: cryptography, identity-based signature scheme, digital signature, bilinear pairings, cryptanalysis

中图分类号: 

• TP309.2