Abstract: Digital image encryption technology is an effective means to protect digital image transmission. An image encryption algorithm based on bit permutation and DNA sequence operations is proposed in this paper. The algorithm firstly uses the Chen system to generate the chaotic map index to scramble the image pixels, and the butterfly network is used to implement the bit permutation. Then the image is coded into DNA matrix, and the algebraic operation is performed with the DNA sequence to realize the substitution of the pixels, which further improves the security of the encryption. Finally, the confusion and diffusion properties of the algorithm are further enhanced by the ciphertext feedback. Experimental results and security analysis show that the algorithm not only has a large key space, the sensitivity of the key, but also can effectively resist statistical analysis and exhaustive analysis attacks.

Key words: image encryption, bit permutation, hyper-chaos, DNA code, DNA sequence

摘要： 提出了一种基于比特置换与DNA序列运算的混沌图像加密的算法。该算法首先利用Chen系统产生混沌映射索引对图像进行像素位置置乱，结合蝶形网络对比特位置乱，以实现位级别置乱。再对图像进行DNA编码，并与核酸序列进行代数运算，实现像素的替代，进一步提高了加密的安全性。最后通过密文反馈来进一步增强算法的混淆和扩散特性。实验和安全性分析结果表明，该算法不仅密钥空间大、对密钥的敏感性强，而且能有效抵御统计性分析和穷举分析等攻击操作。

关键词: 图像加密, 比特置换, 超混沌系统, DNA编码, DNA序列