费雪耶兹算法结合混沌理论的图像加密方案

为解决明文图像与加密密钥无关引起的安全性问题，提出一种基于费雪耶兹算法结合混沌理论的图像加密方案。首先采用一维的Logistic混沌系统针对明文图像特征进行处理生成密钥，密钥作为三维Chen混沌系统的初值，再对三维Chen混沌系统产生的混沌序列进行离散以及量化处理，得到三组伪随机序列。利用费雪耶兹算法与其中两组伪随机序列对图像进行置乱，得到置乱后的图像再与剩余的一组伪随机序列进行扩散变换，得到最终的加密图像。实验测试结果表明，该算法具有良好的安全性，能抵抗大部分攻击。

Image Encryption Scheme Based on Fisher-Yates Algorithm Combined with Chaos Theory

In order to solve the security problem caused by the plaintext image independent of the encryption key， a new image encryption scheme based on Fischer algorithm and chaos theory is proposed. Firstly， the one-dimensional Logistic chaotic system is used to process the characteristics of plaintext image to generate the key. The key is taken as the initial value of the three-dimensional Chen chaotic system. Then， the chaotic sequence generated by the three-dimensional Chen chaotic system is discretized and quantized， and three groups of pseudo-random sequences are obtained. The image is scrambled by using Fischer algorithm and two groups of pseudo-random sequences. The image is then transformed with the remaining pseudo-random sequences to obtain the final encrypted image. Experimental results show that the algorithm has high security and can resist most attacks.