基于多方向像素连续折叠机制与Radon变换的图像加密算法

Image encryption algorithm based on multi-direction pixel continuous folding mechanism and Radon transform

提出了基于多方向像素连续折叠机制与Radon变换的图像加密算法,从不同的方向、利用不同的像素扩散技术来加密明文,显著消除密文周期性。首先,对初始明文完成均等分割,获取左、右两个子块;引入Radon变换机制,对左、右子块进行0°~180°的Radon变换,获取对应的Radon投影谱图像;利用Arnold映射、引力模型分别混淆左、右子块的Radon谱图像,获取两个子置乱密文,将二者进行组合,输出完整的置乱图像。为了从空间多个方向来扩散像素,设计了4个方向连续折叠机制,利用4个不同方向对应的扩散函数来改变像素值,实现图像加密。实验结果表明,与当前图像加密技术相比,所提算法具有更高的安全性与抗攻击能力,输出密文的像素分布更加均匀。

The image encryption algorithm based on multi-direction pixel continuous folding mechanism and Radon trans- form was proposed. Firstly, the initial plaintext was equally segmented to get left and fight sub-blocks. Then the Radon transform was used to obtain the radon projection spectrum image by processing the left and right blocks at 0-180 degrees. And Radon projection spectrum image of left block was permutated by Amold map, while the Radon projection spectrum image of right block was permutated based on gravity model to get two su-scrambling ciphers, then the entire scrambled image is formed by combining them. To diffuse pixels from multiple directions in space, four direction continuous folding mechanism was designed to change the pixel values by using the diffusion function corresponding to four different direc- tions for realizing image encryption. The experimental results show that this algorithm has higher security and attack resis- tance with more uniform ofpixel distribution in output cipher compared with the current image encryption technology.