异构双向签密方案的安全性分析和改进

摘要

Heterogeneous signcryption can be used to guarantee the confidentiality and unforgeability in the different cryptography. In 2016, between traditional public key cryptography and certificateless public key cryptography, the mutual signcryption schemes including PCHS and CPHS were proposed by Liuet al.However, via the security analysis, it is shown that the above schemes are not secure. Firstly, the processes of attack performed by the second type of adversary are described. Secondly, the possible reasons why the second type of adversary can perform these attacks are analyzed. In the end, the original schemes are improved. The improved schemes can overcome the security weakness of the original schemes, and can also ensure the security of data transmission between traditional public key cryptographic and certificateless public key cryptography.%异构签密可以保证异构密码系统之间数据的机密性和不可伪造性.2016年,刘景伟等人提出了传统公钥密码和无证书公钥密码之间的PCHS和CPHS双向异构签密方案.但是,经过分析,发现PCHS方案和CPHS方案均不安全.首先描述了第2类敌手对两个方案的攻击过程,其次分析了两个方案存在第2类敌手攻击的原因,最后对PCHS方案和CPHS方案进行改进.改进方案克服了原方案的安全性问题,保证了传统公钥密码和无证书公钥密码环境之间数据的安全传输.