In order to improve the key space of color image encryption algorithm, the sensitivity to the contents of plain images, the robustness against various types of known attacks, and to achieve the tamper location analysis, a novel color image encryption algorithm based on image hashing, six-dimensional (6D) hyperchaotic and dynamic DNA coding is proposed. Firstly, the color image is pre-processed and the hash sequence is extracted by image hashing algorithm which is used as the initial value and control parameter of chaotic system. Secondly, three color channels of the color image RGB are synthesized into a two-dimensional matrix and the pixels replacement are performed by using the improved two-dimensional chaotic map. Finally, a 6D hyperchaotic system is used to generate random sequences for DNA dynamic coding and arithmetic operations of color images, the encrypted image is obtained. The experimental results show that, compared with the existing methods, the proposed algorithm has a large enough key space, better plain-image sensitivity, better statistical and differential characteristics, as well as can resistant various forms of attacks such as noise and cropping, and the tampering image can be tamper-located analyzed, which has good security and strong robustness.

为了改善彩色图像加密算法的密钥空间，对普通图像内容的敏感度，针对各种已知攻击的鲁棒性并实现篡改位置分析，一种基于图像哈希的新型彩色图像加密算法，提出了六维（6D）超混沌和动态DNA编码。首先，对彩色图像进行预处理，并通过图像哈希算法提取哈希序列，将其作为混沌系统的初始值和控制参数。其次，将彩色图像RGB的三个颜色通道合成为二维矩阵，并且通过使用改进的二维混沌图来执行像素替换。最后，利用6D超混沌系统生成随机序列，对彩色图像进行DNA动态编码和算术运算，得到加密图像。实验结果表明，与现有方法相比，该算法具有足够大的密钥空间，更好的纯图像敏感度，更好的统计和差分特性，并且能够抵抗各种形式的攻击，例如噪声和裁剪，以及篡改图像可以进行篡改分析，安全性好，鲁棒性强。