混沌映射与可逆线性记忆元胞自动机相融合的图像认证加密算法研究

摘要

In order to have the encryption system with image authentication function,and be able to prevent the image being wilfullytamperedby various attacks in the process of storage and transmission,as well as improve its encryption and decryption speed as well as itssecurity,while have the reversible linear cellular automaton possess the memory storage function as well,in this paper we proposed areversiblelinear memory cellular automaton,use image authentication and encryption algorithm integrating the chaotic mapping and thereversiblelinear memory cellular automaton to strengthen the performance of encryption system.What to be used by this algorithm is the imageblock encryption algorithm but not the traditional cipher stream.First,2D phased linear chaotic mapping is used to permute the original plainimage and to alter the position of pixel;then the permuted image is divided into blocks,the Logistic mapping and reversible linear memorycellular automaton are used to carry out diffusion and encryption processing on every block to change its pixel value;afterwards,theseencryptedblocked ciphertexts are composed to form the ciphertext image.Moreover,HASH function is introduced into this algorithm to makethe encryption system have image authentication function.MATLAB simulation software is used to verify this algorithm,the results show thatthis new image authentication encryption algorithm proposed in the paper has excellent encryption performance,it has highly secure diffusionmechanism,high computation efficiency,sufficient key space,and the anti-attack property is significantly improved.%为了使加密系统拥有图像认证功能，能够防止图像在存储与传输过程中被各种攻击肆意篡改，并提高其加解密速度以及安全性，使可逆线性元胞自动机具备记忆贮存功能，提出一种可逆线性记忆元胞自动机。采用混沌映射与可逆线性记忆元胞自动机相融合的图像认证加密算法来增强加密系统的性能，采用的是图像块加密算法，而非传统的密码流。首先采用二维分段线性混沌映射对初始明文图像进行置乱，改变像素位置；然后对置乱图像进行分块，并利用Logistic映射和可逆线性记忆元胞自动机对每一块进行扩散加密处理，改变其像素值，随后将这些加密后的分块密文组合起来形成密文图像；将HASH方程引入到本文算法中，使其拥有图像认证功能。借助MATLAB仿真软件来验证本文算法，结果表明：所提出的图像认证加密新算法具有优异的加密性能，扩散机制高度安全，计算效率高，其密钥空间足够大，抗攻击能力大幅度提升。