公钥密码体制与选择密文安全性

PKC and chosen ciphertext security

讨论了公钥密码体制对选择密文攻击的安全性(简称为选择密文安全性或IND CCA2),比较和分析了几种使一般公钥密码体制达到IND CCA2的方法,对目前所有达到IND CCA2的方法进行了分类,从而找到它们的一个共同特点:构造密文合法性测试.指出了OAEP+的IND CCA2证明中存在的问题,并给出了两种解决方法.

Security against the chosen ciphertext attack of PKC is discussed (simply denoted by chosen ciphertext security of IND-CCA2). Some schemes which make general PKCs IND-CCA2 are compared and analyzed, on the basis of which we classify all the present methods which can obtain IND-CCA2 and find a common idea among them, which is the contruction of a test of ciphertext validity. Finally a problem in the IND-CCA2 security proof of OAEP+ is pointed out together with its two solutions.