无证书签名方案的安全性分析与改进

针对王怡等(王怡，杜伟章.无双线性对的无证书签名方案的分析及改进.计算机应用，2013，33(8)：2250-2252)提出的无双线性对运算的无证书签名方案，指出该方案无法抵抗伪造性攻击，并提出改进方案。改进方案加强了签名算法中参数的关联程度，以抵抗伪造性攻击。安全性分析结果表明，在随机预言机模型下，新方案对于自适应选择消息和身份攻击是存在性不可伪造的。改进方案避开双线性对和逆运算，效率优于已有方案。

Security analysis and improvement of certificateless signature scheme

By analyzing the security of a certificateless signature scheme without bilinear pairing proposed by Wang Y, et al. (WANG Y, DU W. Security analysis and improvement of certificateless signature scheme without bilinear pairing. Journal of Computer Applications, 2013, 33(8): 2250-2252), the result that the scheme can not resist forgery attack was pointed out and an improved scheme was proposed. The improved scheme enhanced the relationship of parameters in signature algorithm to resist forgery attack. The results of security analysis show that the improved scheme is proved to be existentially unforgeable against adaptive chosen message and identity attacks in random oracle model. The improved scheme is more efficient than the existing schemes for avoiding bilinear pairings and inverse operation.