基于混沌系统的图像加密算法设计与应用  

The design and application of image encryption algorithm based on chaotic system

作　　者：郑永爱[1] 王莹莹[1] 王咏梅[1] Zheng Yong'ai;Wang Yingying;Wang Yongmei(Global Institute Of Software Technology,Suzhou 215000,Jiangsu,China)

机构地区：[1]苏州高博软件技术职业学院,江苏苏州215163

出　　处：《长江信息通信》2021年第7期46-50,共5页Changjiang Information & Communications

基　　金：2019年江苏省现代教育技术研究课题(2019-R-69463);2020年江苏省现代教育技术研究课题(2019-R-77049);2020年苏州高职“产教融合、校企合作”教育改革研究课题(JG2020116)。

摘　　要：文章设计了一种"置乱-置乱-扩散"的图像加密方案。首先采用混沌系统Logistic进行像素点置乱,然后进行比特置乱,最后采用超混沌Henon映射和超混沌Chen系统两个混沌系统进行扩散来完成对图像的加密。在图像的像素点置乱阶段,选用了Logistic混沌系统来打乱图像的信息分布。再采用比特置乱对图像进行再次置乱,经过双重置乱后,图像的置乱效果更好。扩散时先利用SHA-256哈希函数生成混沌系统的初始值,得到超混沌Henon映射和超混沌Chen系统的随机变量序列,对超混沌Henon映射和超混沌Chen系统产生的混沌序列进行异或运算,生成新的序列。将该序列转换为密文图像矩阵,从而完成扩散操作。仿真结果表明:设计的加密方案在密钥敏感性、直方图、相邻像素相关性、信息熵等方面具有很好的性能,加密效果良好。A encryption scheme"scrambling-scrambling-diffusion"is designed.Firstly,the chaotic system logistic is used for pixel scrambling,and then bit scrambling.Finally,hyperchaoticHenon mapping and hyperchaotic Chen system are used for image encryption.When scrambling the image pixels,Logistic chaotic system is used to disturb the information distribution of the image.Then the image is scrambled again by bit scrambling,After double scrambling,the scrambling effect is better.In the diffusion process,the SHA-256 hash function is used to generate the initial value of the chaotic system,and the random variable sequence of the hyperchaoticHenon map and the hyperchaotic Chen system is obtained.The XOR operation is performed on the chaotic sequence generated by the hyperchaoticHenon map and the hyperchaotic Chen system to generate a new sequence.The sequence is transformed into ciphertext image matrix to complete the diffusion operation.The simulation results show that the encryption scheme has good performance in key sensitivity,histogram,adjacent pixel correlation,Information entropy and so on.The encryption effect is good.

关 键 词：Logistic系统 超混沌Henon映射 超混沌Chen系统 图像加密 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]