基于多个混沌系统和位运算的图像加密算法

Image Encryption Algorithm Based on Multiple Chaotic Systems and Bit Operations

为了有效改进图像加密效果及安全性,在对基于混沌系统及位运算的图像加密算法进行研究的基础上,提出了一种改进的基于多个混沌系统和位运算的图像加密算法。首先对任意大小灰度进行位平面分解,利用Logistic混沌映射进行混沌排序置乱,再分解成若干个二值图像,利用2-DArnod变换进行置乱,最后对加密后的二值图像组合,生成密文图像。实验结果表明,与置乱扩散加密算法比较,改进算法具有更好的加密效率,密钥空间接近2136,具有较好的安全性,且能较好地抵御擦除和椒盐噪声攻击,有效恢复出原始图像。

In order to effectively improve the image encryption effect and safety, after studying image encryption algorithm based on chaotic systems and bit operations, an improved image encryption algorithm which is based on multiple chaotic systems and bit operations is proposed. Firstly, the original image is decomposed into bit-planes, and chaotic sequence scrambling is done by using Logistic chaotic map, and then it is divided into several binary images. Each divided bit plane is operated by 2-DArnod transformation to scramble. Finally, the encrypted binary images are combined to obtain the final ciphertext image. The experimental result shows that compared with diffusion scrambling encryption algorithm, the modified algorithm achieves a better encryption, and the key space is near to . It has a better security and can be against the attack of and salt-pepper noise. It also can recover the original picture.