Abstract: Image encryption is an essential method of protecting image security. Existing image encryption schemes are not very secure and have low encryption and decryption efficiency, and cannot resist various types of attacks. In response to the above problems, an image encryption algorithm based on fully scrambled hyperchaotic sequences and multi-ary DNA encoding is proposed, which can improve the encryption efficiency while ensuring the security of ciphertext images. First, combined with the content of the grayscale image, an image hash algorithm and an external key are used to generate the initial values of the five-dimensional hyperchaotic system and the logical map. Secondly, the original image is converted into a four-valued image, and the random sequence generated by five-dimensional hyperchaotic system and logical map is used to perform DNA encryption on the image, including four stages of DNA encoding, DNA scrambling, DNA diffusion and DNA decoding. Finally, the image is decomposed into bit planes, and the random matrix generated by five-dimensional hyperchaotic system and logical map is used to perform XOR operations with the high four-bit plane and the low four-bit plane respectively to obtain the final ciphertext image. Experimental results show that the image encryption algorithm has the advantages of large key space, strong key sensitivity, good encryption effect and high encryption efficiency. It can resist a variety of conventional attacks such as statistical analysis, differential attacks, clipping attacks, and noise attacks.

摘要： 图像加密是保护图像安全性的重要方法。现有的图像加密方案安全性不高且加解密效率较低，无法抵御多种类型的攻击。针对上述问题，提出了一种基于全置乱超混沌序列和多进制DNA编码的图像加密算法，可以在提高加密效率的同时，保证密文图像的安全性。首先，结合灰度图像的内容，使用图像哈希算法和外部密钥生成五维超混沌系统和逻辑映射的初始值。其次，将原始图像转换为四值图像，使用五维超混沌系统和逻辑映射生成的混沌序列，对图像进行DNA加密，包括DNA编码、DNA置乱、DNA扩散和DNA解码四个阶段。最后，对图像进行位平面分解，利用五维超混沌系统和逻辑映射生成的随机矩阵分别与高四位平面和低四位平面做异或运算，得到最终的密文图像。实验结果证明，该图像加密算法具有密钥空间大、密钥敏感性强、加密效果良好、加密效率高等优点，能够抵抗统计分析、差分攻击、裁剪攻击和噪声攻击等多种常规攻击方式。