基于DNA编码的安全高效的图像加密算法

摘要

提出一种基于DNA随机编码与随机运算结合混沌映射的图像加密算法.由图像的SHA-256的哈希值来生成算法所需要的密钥,将Lorenz和Logistic混沌映射作为密钥发生器,产生所有的初始参数.采用Lorenz混沌映射对图像的像素值进行置换以及生成随机DNA掩码;为了增强随机性以及克服有限的DNA运算规则,通过Logistic映射随机决定的8种DNA编码中的1种对图像逐行进行编码;提出DNA同或运算,进而使编码图像与DNA随机掩码逐行进行Logistic映射随机决定的4种DNA运算中的一种;对运算后的编码图像进行随机解码,得到最终加密图像.仿真结果表明,提出的算法能够抵制各种典型的攻击,具有很强的安全性.%In this paper,an image encryption algorithm based on DNA random coding and random operation combined with chaotic map is proposed.SHA-256 hash of the plain image is used to generate secret keys and Lorenz Map and Logistic Map are applied to generate all parameters the presented algorithm needs.Lorenz chaotic map is exploited to permute the pixels of color components;R,G and B,at the same time generate random DNA masks.In order to get the high randomness and overcome the limitations of DNA computing rules,encode the plain image with DNA rules by rows respectively and different rows are encoded according to eight rules selected by logistic map;Then,employ encoded plain image to conduct DNA operations with encoded DNA masks row by row to obtain an intermediate image and the one of the four DNA operations including proposed DNA XNOR operation executed every row randomly is chosen by logistic map;Finally,randomly decode the intermediate image to get the ultimate cipher image.Simulated experimental results indicated that the proposed algorithm was capable of withstanding typical attacks and had good character of security.