基于置乱切换决策机制和声搜索的图像加密算法  

Image encryption algorithm based on scrambling switching decision mechanism harmony search

作　　者：陈煜欣[1] 

机构地区：[1]环境保护部信息中心,北京100029

出　　处：《沈阳工业大学学报》2017年第3期333-339,共7页Journal of Shenyang University of Technology

基　　金：环保部环保公益行业科研专项基金资助项目(201509090)

摘　　要：为解决当前图像加密算法因其置乱过程存在周期性而难以有效降低相邻像素间的紧密度,导致其安全性不高的问题,提出了一种置乱切换决策机制耦合动态和声搜索的图像加密算法.将明文分割成均等图像子块,通过Logistic映射形成一组随机数组,并定义置乱切换决策机制,根据切换参数选择合适的置乱函数对各子块进行置乱.以图像熵值与相邻像素间的紧密度为目标函数,替换传统的和声搜索模型.通过改进和声搜索机制输出的最佳密钥设计像素加密函数并反复搜寻优化,使相邻像素间的紧密度最小.结果表明:与当前图像加密技术相比,所提算法的安全性更高,具有更高的抗剪切攻击与抗差分攻击能力.该算法能够较好地用于QR二维码以及数字图像的信息加密.In order to solve the low security problem caused by the fact that it is difficult to reduce effectively the closeness between adjacent pixels because of the periodicity in the scrambling process for the current image encryption algorithms, an image encryption algorithm based on scrambling switching decision mechanism coupling with dynamic harmony search was proposed. The plain text was divided into equal image sub-blocks, and a random array group was obtained through Logistic mapping. In addition, the scrambling switching decision mechanism was defined, and the sub-blocks were permutated through selecting the appropriate scrambling function according to the switching parameters. The closeness between the image entropy and adjacent pixels was taken as the objective function, and was used to replace the traditional harmony search model. Through improving the optimal secret key exported by the harmony search mechanism and performing the repeated searching and optimization, the smallest closeness between adjacent pixels was obtained. The results show that compared with the current image encryption techniques, the proposed algorithm has higher security as well as better shear and differential attack resistances.

关 键 词：图像加密 置乱切换决策机制 和声搜索算法 切换参数 Zigzag扫描 像素加密函数 LOGISTIC映射 加密函数 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]