基于双混沌和彩色图像的空间加密算法

Spatial Encryption Algorithm Based on Double Chaos and Color Image

针对大量彩色图像加密算法中的混沌序列具有单一性、加密算法具有独立性这两个缺点,设计了一种基于双混沌和彩色图像的空间加密算法。该算法利用了彩色图像可分解为三层分量这一特点,对三层分量采用有关联(平行置乱-有序扩散)的加密模式,使得难以单一破解彩色图像的其中任意一层分量,并且借助Henon映射和四维超混沌结合多组初始条件生成复杂混沌序列,将其用于加密过程。对加密算法进行仿真实验,结果表明,NPCR为99.6108%,UACI为33.4606%,信息熵为7.9975,密钥空间为10^16×21。所提算法密钥空间之大足以抵抗穷举攻击,通过分析可知该算法可以抵抗差分攻击,并且该算法可有效地解决混沌序列的单一性、加密算法的独立性这两个问题,使得破解难度增加。将其与其他类似的彩色图像加密算法进行比较,结果表明文中加密算法的安全性更高。

Aiming at the shortcomings of single character of chaotic sequences in a large number of color image encryption algorithms and the independence of encryption algorithms,a spatial encryption algorithm based on double chaos and color images was designed.The algorithm can be decomposed into three layers by using color images.A feature that uses an associated(parallel scrambling-ordered diffusion)encryption mode for the three-layer component,making it difficult to simply singulate any one of the components of the color image,and combining multiple sets of initial conditions with Henon mapping and four-dimensional hyperchaos Generate complex chaotic sequences for use in the encryption process.The simulation results of the encryption algorithm show that the NPCR is 99.6108%,the UACI is 33.4606%,the information entropy is 7.9975,and the key space is 10^16×21.The algorithm key space is large enough to resist exhaustive attacks,and the analysis results show that the algorithm can resist differential attacks.And the proposed algorithm can effectively solve the singularity of chaotic sequence and the independence of encryption algorithm,which makes.Compared with other similar color image encryption algorithms,the encryption algorithm in this paper is more secure.