公钥加密体制选择密文安全性的灰盒分析

Gray-box analysis of chosen ciphertext security for public key encryption scheme

为了更简单准确地判断公钥加密方案的IND-CCA2安全性,提出了IND-CCA2安全性的灰盒分析法。该方法对解密服务产生的信息泄露进行了详细完备的分解,然后通过分析每一类信息泄露的可能性来判定方案的IND-CCA2安全性。与IND-CCA2安全性的规约证明相比,灰盒分析更加简单容易理解,更适合作为公钥加密体制IND-CCA2安全性的评测方法。最重要的是,灰盒分析的信息泄露分析不仅可以判定公钥加密体制的IND-CCA2安全性,还可以发现方案不安全的原因,为方案的设计提供依据和指导。

To evaluate the IND-CCA2 security of public key encryption schemes, proposed the gray-box analysis of IND-CCA2 security. In the new method, evaluated the IND-CCA2 security by careful catalog and analysis of the information leak of decryption oracle. Compared with the reduction proof, gray-box analysis was more simple and easy to understand, and more suitable to be used as an evaluation method of the public key encryption scheme＇ s IND-CCA2 security. Most importantly, the analysis of the decryption oracle＇ s information leak not only can evaluate the IND-CCA2 security of a scheme, but also can find the reason of insecurity. This provides direction information for the design of IND-CCA2 schemes.