一种服务器辅助验证聚合签名方案的安全性分析及改进

摘要

为提高服务器辅助验证聚合签名的安全性,在共谋攻击和自适应选择消息攻击下,提出一种新的服务器辅助验证聚合签名的安全模型.分析了牛淑芬等人(计算机应用研究,2015年第7期)提出的基于聚合思想的服务器辅助验证签名方案的安全性,发现该方案无法抵抗服务器与非法签名者的共谋攻击.针对该安全性缺陷,在新的安全性定义下提出一种改进方案,并在共谋攻击和自适应选择消息攻击下证明了新方案是安全的.分析结果表明,该方案能有效降低签名验证算法的计算复杂度,并具有固定的聚合签名长度.%To improve the security of server-aided aggregate verification signature,a new security model of server-aided aggregate verification signature against collusion and adaptive chosen message attacks is presented.It analyzes the security of server-aided aggregate verification scheme proposed by Niu et al (Application Research of Computers,2015,No.7),and finds that this scheme cannot resist collusion attack between a server and a signature forger.In view of security shortcomings,an improved scheme is proposed under the new security definition.The proposed scheme is proven to be secure under collusion attack and adaptive chosen message attack.Analysis results show that the new scheme can effectively reduce computational complexity of signature verification algorithm,and it has the fixed length of aggregate signature.