基于细胞自动机的安全图像加密算法

Secure Image Encryption Algorithm Based on Cellular Automata

利用初等细胞自动机状态环性质进行加密后的密文图像仍可看出原图像的部分轮廓,且明文敏感性差。由此提出一种安全的图像加密算法,采用周期为2的二维细胞自动机对图像进行位平面加密,再通过状态环加密的方法使明文改变1 bit即可影响整个密文图像。仿真结果表明,改进算法敏感性更高,密钥空间更大,且加密速度较快。

In order to solve the problems that the cipher image encrypted by encryption algorithm based on the merit of the state attractors of Elementary Cellular Automata（ECA） can still discern part outline of the original image, and the plaintext sensitivity is poor, this paper proposes a secure image encryption algorithm. It employs the method which encrypts every bit plane with period two 2D Cellular Automata（CA）, and then uses state attractors to encrypt the image, to achieve the effect that 1 bit change in the plaintext can be spreaded to the whole cipher image. Simulation results show that the improved algorithm is more sensitive, has larger key space, and easy to implement.