融合Hénon映射和元胞自动机的图像加密算法

Image Encryption Algorithm Based on Hénon Map and Cellular Automata

为增强数字图像在通信传输中的安全性,提出了一种结合了Hénon映射和元胞自动机优良特性的图像加密算法.该算法先将明文图像转换为二进制矩阵,根据外部密钥使用Hénon映射采取逐级迭代法产生伪随机序列,依据伪随机序列采用初等元胞自动机演化规则对图像信息逐行逐列地进行扩散,迭代3次后得到加密图像.经过仿真实验表明,该图像加密算法所需伪随机序列短,加密速度较快,并且对密钥、明文和密文均具有良好的敏感性,与测试指标的理论值最大相对误差仅为0.0417%,能够有效地抵抗各类被动攻击.

In order to enhance the security of digital image in communication,an image encryption algorithm is proposed by combining Hénon map and cellular automata.The algorithm first converts the plaintext image into a binary matrix,and then a pseudo-random sequence is generated by a step-by-step iterative method using Hénon map according to the external key.Using to the pseudo-random sequences,the image information is diffused row by row and column by column with the help of elementary cellular automata evolution rules.The encrypted image is obtained after repeating the diffusion iterating three times.The simulation results show that the proposed algorithm has short pseudo-random sequence,fast encryption speed,good sensitivity to the key,plaint-image and cipher-image for the maximum relative error of their indexes is only0.047%,and can effectively resist all kinds of passive attacks.