关于窃听敌手不可区分与CPA安全的一个反例  

On a Counterexample Related to Indistinguishable Encryptions for an Eavesdropper and CPA Security

作　　者：常金勇[1] 李海增[1] 

机构地区：[1]长治学院数学系,长治046011

出　　处：《科学技术与工程》2013年第16期4717-4719,共3页Science Technology and Engineering

基　　金：山西省高校科技研究开发项目(20111129);山西省大学生创新性实验项目(2011361)资助

摘　　要：在密码学中,窃听敌手不可区分与CPA(选择明文攻击)安全这两个概念有着"天然"的不等价性。对于私钥加密方案来说,窃听敌手不可区分的多次加密又是介于这两者之间的一个概念。这也是私钥加密方案与公钥加密方案非常重要的一个区别。针对一个具体构造的例子,通过运用"归约"和"混合论证"这两个密码学中最常用的方法详细论述了窃听敌手不可区分的多次加密与CPA安全之间的区别。从而,有助于人们对于前述三个概念进行区分。In cryptography, the notions indistinguishable encryptions in the presence of an eavesdropper and CPA （ chosen plaintext attack） security are not equivalent naturally. In symmetric key encryption, indistinguishable multiple encryptions in the presence of an eavesdropper is also a concept falling in between them, which is a signifi- cant difference between private key encryption and public key encryption. A concrete example is discussed which can explain the difference between indistinguishable multiple encryptions in the presence of an eavesdropper and CPA security using ＂reduction＂ and ＂hybrid reasoning＂ that are often used in cryptography so that we have a un- ambiguous cognition for those notions mentioned above.

关 键 词：窃听敌手 选择明文攻击 加密方案 

分 类 号：TP309.08[自动化与计算机技术—计算机系统结构]