混沌系统具有良好的伪随机性、混频特性、对初始状态的敏感性、复杂的映射参数等特性,这些特性与密码学要求的产生伪随机信号、混乱和扩散、加解密密钥的难以预测等属性是十分吻合的。因此近些年来,不少学者提出了多种基于混沌理论的密码算法,但对其安全性大多草草一笔带过,并没有详尽的安全性分析。本文针对一种较新的基于Feistel结构的混沌分组密码,应用不可能差分的分析方法,分别在固定s盒、动态s盒两种情况对该算法进行了分析。分析结果表明,相比较于传统分组密码,该混沌分组密码能够更有效的抵抗差分密码攻击。
Chaos system has many excellent properties, such as pseudo random,frequency mixing,sensitivity of the initial value, complex mapping parameters, these properties are consistent with the requirements of cryptography: producing pseudo -random signal, confusion and diffusion, difficulty to predict the keys. In recent years, many scholars proposed cryptographic algorithms based on chaos theory, but without detailed security analysis. In this paper, we use impossible differential cryptanalysis to analyze a new kind of chaotic block cipher based on Feistel structure with fixed S -box and dynamic S -box. The result shows that com- pared to traditional block cipher, the block cipher based on chaos is more effective against differential crypta- nalysis.