对一个基于细胞自动机的分组密码变形的分析

摘要

Subhayan Sen et al. have proposed a block cipher system CAC(cellular automata based cryptosystem)based on cellular automata theory, but they have not given a detailed description of some of its modules. From the point of view of application, one module of CAC is fixed, and the variant is called SMCAC (same major-CA CAC).The analysis of SMCAC is given, and the results show that the variant of this cipher is very insecure under chosen-plaintext attacks. Using cryptanalysis of the variant for reference, attacks on the cipher itself may be found when some of the design details of the cipher are known.%Subhayan Sen等人提出了一个基于细胞自动机的分组密码系统(cellular automata based cryptosystem,简称CAC),但并没有给出CAC的某些构造模块的细节描述,从应用角度考虑,将其中的一个模块固定得到CAC的变形--SMCAC(samemajor-CACAC).对SMCAC进行密码分析,结果表明,CAC的这种变形在选择明文攻击下是极不安全的.对SMCAC进行分析的意义在于,知道CAC的具体设计细节以后,借鉴对SMCAC的分析,有可能对CAC密码系统本身的安全性造成威胁.