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.

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.

Supported by the National Natural Science Foundation of China under Grant Nos.60373047,90304007(国家自然科学基金);the National Grand Fundamental Research 973 Program of China under Grant No.G1999035802(国家重点基础研究发展规划(973))