一种基于Lorenz混沌系统的有效图像加密算法

An Effective Image Rryptosystem Based on the Hyper Chaotic Lorenz System

提出一种基于Lorenz超混沌系统和动态DNA编码的图像加密算法.首先利用SHA-384哈希函数生成混沌系统初始值,接着得到混沌随机变量序列,然后利用该序列构造DNA编码规则矩阵,使得图像上不同的像素点对应不同的DNA编码规则.为了提高安全性,引入基于随机数的DNA置乱机制,再进行一次置乱,最终得到密文图像.实验结果和安全性分析显示该算法能起到很好的置乱效果,并且能够抵抗多种攻击.

This paper presents a color image crypto system based on the Lorenz hyper-chaotic system and dynamic DNA coding.Firstly,the initial values of the chaotic system and four intermittent parameters are computed by the secret key K which is generated by SHA-384 hash function of the plain image.Secondly iterate the hyperchaotic system to get the chaotic sequences,then a DNA encoding matrix is obtained by the chaotic sequences,subsequently different pixels in the image correspond to different DNA coding rules.In order to improve the security,diffusion mechanism based on random number related to plaintext is introduced to diffuse the DNA matrix of the original image,and the color cipher image is obtained.Experimental results and security analysis demonstrate that our encryption algorithm has good performance and may resist against various typical attacks.