基于混沌映射和DNA序列运算的数字图像加密算法

Digital image encryption algorithm based on chaotic map and DNA sequence operation

提出一种混沌映射和DNA序列运算相结合的图像加密算法。该体系结构包括置乱和扩散两部分,置乱过程将锯齿形混淆算法和约瑟夫环置乱相结合提出一个变步长分块置乱的方法;扩散过程将置乱后的红、绿、蓝分量转换为三个DNA矩阵,引入DNA计算来扩散三个DNA矩阵。将混沌系统与哈希函数SHA-256相结合,使得DNA编码和混沌序列的产生都依赖于明文信息。因此,算法对明文图像有很高的敏感性。采用512×512×3的Lena彩色图像进行测试,Lena密文图像相邻像素的相关系数接近于0,信息熵达到7.9997。实验结果和安全性分析表明,算法具有良好的加密效果和可靠的安全性能。

To solve this problem,an image encryption algorithm combining chaotic mapping and DNA sequence operation is proposed.The architecture includes two parts:scrambling and diffusion,and the scrambling process combines the zigzag obfuscation algorithm and Joseph's ring scrambling to propose a variable step size block scrambling method.The diffusion process converts the scrambled red,green,and blue components into three DNA matrices,and introduces DNA calculations to diffuse the three DNA matrices.Combining chaotic systems with the hash function SHA-256 makes both DNA coding and chaotic sequence generation dependent on plaintext information.Therefore,the algorithm has a high sensitivity to plaintext images.The Lena color image of 512×512×3 was used for testing,and the correlation coefficient of neighboring pixels of the Lena ciphertext image was close to 0,and the information entropy reached 7.9997.Experimental results and security analysis show that the algorithm has good encryption effect and reliable security performance.