基于黄金分割-Lucas动态置乱与异扩散的图像加密算法

当前图像加密算法的每一轮像素位置置乱过程都是相同的,且扩散操作是有序的,降低了算法的动态性与随机程度,使得算法安全性不佳.为了解决这一问题,本文提出了黄金分割-Lucas动态置乱与异扩散的图像加密算法.首先,引入黄金分割序列与Lucas序列,基于2D Arnold映射变换思想,设计了动态置乱机制,根据不同的迭代次数,动态改变其置乱变换核,使得每一次像素置乱操作都是不同的,有效提高明文像素置乱度;联合Cosine映射、sine映射与Logistic映射,设计复合串联混沌映射,利用置乱密文的像素总量来生成复合映射的初始条件,输出伪随机序列,并构造量化函数,对其进行量化,获取一组密钥流;最后,对置乱图像像素进行分组,并结合密钥流,设计两个加密引擎函数,通过构造像素加密模型,分别对图像第一个像素、中间像素以及最后一个像素进行异扩散,完成图像的加密.实验结果表明,与当前混沌加密技术相比,所提算法具有更高的安全性与用户响应,具备更强的抗明文与抗噪声攻击能力.

On Image Encryption Algorithm Based on Gold Segmentation-Lucas Dynamic Scrambling and Different Diffusion

In order to solve the defect such as low dynamic and random degree resulting in low security caused by same pixel location scrambling process with each round, and the orderly diffusion operation, the image encryption algorithm based on gold segmentation-Lucas dynamic scrambling and different diffusion has been proposed in this paper. Firstly, the plaint pixel scrambling degree was effectively improved by introducing the gold segmentation-Lucas transform mechanism to dynamic transform the permutation changing kernel according to the iteration number so that the pixel scrambling operation is different during each round. Then the complex tandem chaotic mapping was designed based on Cosine map, sine map and Logistic map to produce its initial conditions according to the pixels number of cipher for outputting the random sequence, and a quantization function was constructed to quantifies the sequence to obtain the key-streams. Finally, the block image is grouped, and the two encryption engine functions are designed combination with the key stream. By constructing the pixel encryption model, the first pixel, middle pixels and the last pixel of the image is diffused to finish the image encryption. The experimental results show that this proposed algorithm has higher security and user response with stronger anti-shear, anti-plaintext attack capability compared with the current chaotic encryption technology.