一种带有猫映射动态置换盒的分组密码

A block cipher with dynamic S-boxes based on arnold map

对猫映射的混沌特性进行研究,提出一种基于迭代二维猫映射的动态置换盒(S-盒)生成方法,由此构造一种基于S-盒的加密算法。将明文划分成组,与不同S-盒进行加密,通过32轮的替代和循环左移得到密文分组。为了提高密码系统的安全性,利用密文反馈来改变猫映射的状态值,使得S-盒与明文相关,可提高密码系统的混淆与扩散性能。由于加密使用了动态S-盒,密码系统不会遇到固定结构分组密码的问题。实验结果表明,该密码系统具有较高的安全性,适用于保密通信。

Chaotic characteristics of Arnold map are studied,and a method for generating substitution boxes（S-boxes） based on the iterating Arnold map is presented.On this basis,a block encryption scheme based on dynamic S-boxes is proposed.The plaintexts are divided into blocks and encrypted with different S-boxes.The cipher blocks are obtained by 32 rounds of substitution and left cyclic shift.To improve the security of the cryptosystem,a cipher feedback is used to change the state value of the Arnold map,which makes the S-boxes relate to the plaintext and enhances the confusion and diffusion properties of the cryptosystem.Since dynamic S-boxes are used in the encryption,the cryptosystem does not suffer from the problem of fixed structure block ciphers.Theoretical and experimental results indicate that the cryptosystem has high security and is suitable for secure communications.