一种新的混沌分组密码算法

New Block Cryptosystem Based on Chaotic System

提出了一种新的分组密码算法,该算法把128比特的明文加密为128比特的密文。算法的密钥由128位的比特流K和Logistic映射的初值x0两部分组成。整个加密过程包含了一个初始变换、8个轮变换和最后的一个输出变换。每一轮使用一个128比特的轮密钥K(r)来加密上一轮的输入C(r-1),并把输出反馈到下一轮的输入。所有的轮密钥都是由128位的比特流K和由Logistic映射产生的128比特随机二进制序列导出。理论与实验分析表明该算法克服了一些纯混沌密码系统的固有缺陷,具有较高的性能。

A new block cipher is proposed based on the study of some existing chaotic encryption algorithms. The proposed cipher encrypts 128-bit plaintext to 128-bit ciphertext blocks, using a 128-bit key K and the initial value xn and the control parameter μ of logistic map. The block cipher process consists of an initial permutation and eight computationally identical rounds followed by an output transformation. Round r uses a 128-bit roundkey K^（r） to transform a 128-bit input C^（r-1）, which is fed to the next round. The output after round 8 enters the output transformation to produce the final ciphertext. All roundkeys were derived from K and a 128-bit random binary sequence generated from a chaotic map. Analysis shows that the proposed block cipher does not suffer from the flaws of pure chaotic cryptosystems and possesses high security.