【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。更多还原

【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.更多还原