针对一类无证书签名方案的攻击及改进

摘要

For the security problem, which is insecure against public-key replacement attack, on the certificateless signature scheme proposed by Su et al.'s, this paper proposes an improved certificateless signature scheme. The proposed scheme simplifies the process of verification. Analysis results show that the improved scheme is secure against public-key replacement attack and is provably secure against existential forgery under adaptively chosen message attack in the random oracle model.%苏万力等人提出的无证书签名方案(江苏大学学报,2009年第4期)中存在公钥替换攻击的安全问题,敌手可以通过替换签名者的公钥对任意的消息进行签名伪造.针对该问题,提出一种改进的无证书签名方案,并对签名验证算法进行简化.分析结果表明,改进方案能抵抗公钥替换攻击,在随机预言机模型下,还能抵抗适应性选择消息攻击下的存在性伪造.