基于组合混沌系统和交换策略的彩色图像加密算法

Color Image Encryption Scheme Based on Hybrid Chaotic Systems and Exchange Strategy

针对传统的图像加密算法的抗统计分析能力差、加密系统安全性能不足的缺点,提出一种新的基于混沌系统的图像加密方法.通过已经成熟的Arnold映射来改变图像像素位置和交换图像像素灰度值比特位信息,破坏原图像像素位置的相关性.表现在图片视觉上的特点是使图像信息混乱无法直接阅读出信息,同时像素灰度值的比特位信息交换破坏了原图像的灰度统计信息,能够有效地对抗各种统计分析.得到的置乱图像再通过由Tent映射得到的混沌序列作为密钥流进行像素灰度值扩散,使得灰度值信息充分混合后得到安全性能优秀的加密图像.该加密图像能够有效应对差分攻击等破解手段.

In this paper,a new image encryption method based on chaotic system is proposed aiming at the poor anti-statistical analysis ability of the traditional image encryption algorithm and the security performance of the encryption system.The mature Arnold mapping is used to change the image pixel position and exchange the gray value bit information of the image pixel,which damages the correlation of the original image pixel position.The visual characteristics of the images are that the image information is confused and the information cannot be read directly.At the same time,the bit information exchange of the pixel gray value damages the gray statistical information of the original image,which can effectively resist various statistical analyses.The chaotic sequence obtained by Tent mapping is used as the key stream for pixel gray value diffusion,so that the gray value information is fully mixed to obtain an encrypted image with excellent security performance,which can effectively deal with differential cryptanalysis and other cracking methods.