【摘要】 针对目前多图像加密算法中置乱效果不佳、DNA编码模式固定及密钥更新方式实用性低等问题，提出了一种基于动态密钥更新与DNA动态交错编码的加密方案。首先，设计了一种利用SHA-256的动态密钥更新方案，通过限制新密钥中的明文信息量摆脱一次一密的密钥系统。其次，改进了三维循环移位置乱方法，并以此降低明文中的相关性。随后，根据混沌序列动态选取DNA编码规则及编码顺序，并在此基础上将图像矩阵逐像素动态交错编码为DNA序列。最后，将编码后的DNA序列与给定序列进行碱基运算完成对明文图像的加密。仿真实验表明，该算法密文图像的相关性可低至10^-3,全局信息熵可达7.999 4。该算法能抵挡各种攻击方式，具有较高安全性。更多还原

【Abstract】 To solve the problems of poor scrambling effect, fixed DNA encoding pattern, and low practicality of key update method in current multi-image encryption algorithms, an encryption scheme based on dynamic key update and dynamic interleaved DNA encoding is proposed.Firstly, a dynamic key update scheme using SHA-256 is designed to discard the one-time pad key system by limiting the amount of plaintext information in the new key.Secondly, the 3D cyclic-shift position permutation scheme is improved and used to reduce the correlation in the plain image.Subsequently, the DNA encoding rules and order are dynamically selected based on the chaotic sequence, and the image matrix is dynamically interleaved pixel by pixel to encode the DNA sequence on this basis.Finally, the encoded DNA sequence is calculated with the given sequence based on the principle of complementary base pairing to complete the encryption of plain images.Simulation shows the correlation of the cipher image can be as low as 10^-3 and the global information entropy can reach 7.999 4.The algorithm can resist various attack methods and has high security.更多还原