基于混沌系统的数字彩色图像加密技术

Digital Color Image Encryption Technology Based on Chaos System

近年来,彩色图像的安全存储与传输一直受到学者们的关注,现有的低维混沌系统和单调DNA编码系统因其结构单调、繁杂度和安全性较低,不能满足图像加密的最根本要求。在此基础上提出一种基于混沌系统与DNA编解码相结合的彩色图像加密算法。首先,对彩色图像的分块进行加密;其次,将Logistic混沌映射生成的参数与空间复杂的Chen超混沌映射结合;再次,对彩色图像的红色(red,R)、绿色(green,G)和蓝色(blue,B)的3个通道进行置乱;最后,利用DNA编码对图像进行混乱加密处理。同时增加了加密算法中混沌系统的个数,优化了加密算法的流程。改进算法在MATLAB 2018b上进行仿真,通过直方图、信息熵和相邻像素相关性等对仿真结果进行安全性分析,结果表明改进算法提高了加密算法的加密效率,并增强了加密的安全性。

In recent years,the secure storage and transmission of color images has attracted the attention of scholars.The existing low-dimensional chaotic systems and monotonic DNA coding systems can't meet the most fundamental requirements of image encryption because of their monotonous structure,low complexity and low security.On this basis,a color image encryption algorithm based on the combination of chaotic system and DNA encoding and decoding was proposed.Firstly,the blocks of color image were encrypted.Secondly,the parameters generated by Logistic chaotic map were combined with spatially complex Chen hyperchaotic map.Thirdly,the three channels of red(R),green(G)and blue(B)of the color image were scrambled.Finally,DNA coding was used to encrypt the image.At the same time,the number of chaotic systems in the encryption algorithm was increased,and the process of the encryption algorithm was optimized.The improved algorithm was simulated on MATLAB 2018b,and the security analysis of the simulation results was carried out through histogram,information entropy and adjacent pixel correlation.The results show that the improved algorithm improves the encryption efficiency of the encryption algorithm and enhances the encryption security.