内部安全模型下几个签密方案的密码分析

Cryptanalysis of some signcryption schemes in insider-security model

针对五个文献中的六个签密方案,分析了它们在内部安全模型下的保密性和不可伪造性。分析表明有五个方案存在保密性攻击,有四个方案存在伪造性攻击,提出了一些针对这些方案的攻击方法,并分析了攻击成功的原因。针对这些方案的安全缺陷,使用签名部分绑定接收者和加密部分绑定发送者的方法,分别给出了能有效克服攻击的改进措施。

This paper analyzed the confidentiality and unforgeability of six signcryption schemes in five papers under insider-security model.The analysis results show that there’s existing confidentiality attacks in five schemes and forgeability attacks in four schemes.Then this paper presented some concrete attack methods for these schemes,and analyzed the reasons for the success of attacks.According to the security flaws of these schemes,using the methods of binding receiver in signature part and binding sender in encryption part,it put forward countermeasures against these attacks respectively