基于Lorenz映射和Logistic映射的图像分块加密算法

An image block encryption algorithm based on Lorenz map and Logistic map

针对当前大多数图像加密算法安全性较低,且无法抵御选择明文攻击的问题,提出了一种基于Lorenz映射和Logistic映射的图像分块加密算法。算法采用Logistic映射对明文图像进行置乱操作;对置乱后的图像进行分块;利用Lorenz映射产生的混沌序列分别对图像进行块内扩散操作和块间扩散操作,得到加密后的密文图像。仿真结果表明,算法密钥空间大,敏感性高,加密效果较好。

Aiming at the problem that most of the image encryption algorithms are low security and can’t resist the choice of plaintext attack,an image block encryption algorithm based on Lorenz mapping and Logistic mapping is proposed.The algorithm first uses Logistic mapping to scramble the plain image.Secondly,the image after the scramble are divided into blocks.Then,the chaotic sequence generated by the Lorenz map is used to perform the intra-block diffusion operation and the inter-block diffusion operation respectively,and the encrypted cipher image is finally obtained.Experimental results show that:the algorithm has large key space,high sensitivity and good encryption effect.