基于Chen超混沌和DNA编码的图像加密算法  

Image encryption algorithm based on Chen hyperchaos and DNA coding

作　　者：李志远[1] 蒋爱平[1] 沈彦琦 LI Zhiyuan;JIANG Aiping;SHEN Yanqi(College of Electronic Engineering,Heilongjiang University,Harbin 150080,China)

机构地区：[1]黑龙江大学电子工程学院,哈尔滨150080

出　　处：《黑龙江大学自然科学学报》2020年第5期602-609,共8页Journal of Natural Science of Heilongjiang University

基　　金：国家自然科学基金资助项目(51607059);黑龙江省自然科学基金资助项目(QC2017059);黑龙江省博士后基金资助项目(LBH-Z16169);黑龙江省教育厅科技成果培育项目(TSTAU-C2018016);黑龙江大学科研项目(HDJMRH20191)。

摘　　要：提出了一种基于Chen超混沌和DNA编码的图像加密算法。算法关键在于对Logistic映射进行迭代,得到伪随机序列,并将该序列转为二维矩阵;改变参数和初始值,再次迭代Logistic混沌系统,得到新的伪随机序列,并构造索引序列完成对原始图像的置乱及扩散,使原始图像的位置及像素值均改变。再利用参数多、空间复杂的Chen超混沌,得到四条混沌序列即X、Y、Z和H。用X和Y序列的随机值控制DNA编码规则的选取,使编码具有随机性和不确定性,分别对转化的二维矩阵和扩散后的图像进行编码,得到DNA矩阵。对两矩阵进行DNA运算,运算方式由序列Z的随机值决定,最后根据序列H进行解码,解码和编码的规则不同,进一步加强了安全性,得到最终加密图像。加密方案在Matlab上进行仿真,通过对密钥空间、密钥敏感性、直方图、信息熵和像素相关性等进行安全性分析,可以看出本算法可获得较好的加密效果,不易被破解。An image encryption algorithm is proposed based on Chen hyperchaos and DNA coding.The pseudo-random sequence is generated by iterating the Logistic map,which will be converted to a two-dimensional matrix with the parameters and initial values being changed.The Logistic chaotic system is iterated again to get a new pseudo-random sequence,and the index sequence is constructed to complete the scrambling and diffusion of the original image,so that the position and pixel values of the original image are changed.Then,Chen hyperchaos with many parameters and complicated space are introduced to obtain four chaotic sequences,namely X,Y,Z,H.Using the random values of X and Y sequences controls the selection of DNA coding rules,so that the coding has randomness and uncertainty.The transformed two-dimensional matrix and the diffused image are encoded to obtain a DNA matrix.Next,DNA matrix performs a DNA operation on the two matrices with the operation method being determined by the random value of the sequence Z.Decoding is performed according to the sequence H,different decoding and encoding rules further enhance security so as to get the final encrypted image.The encryption scheme is simulated on Matlab.Through security analysis of key space,key sensitivity,histogram,information entropy,pixel correlation,etc.,it can be seen that the algorithm in this paper can obtain better encryption results and is not easy to be cracked.

关 键 词：Chen超混沌 LOGISTIC混沌映射 DNA编码 图像加密 

分 类 号：Q939.97[生物学—微生物学]