关键词: 信息安全, 数字图像置乱, 三维亚仿射变换, 周期性, 奇异点

Abstract: In order to improve the security and flexibility of digital image information hiding, adopting the theory of sub-affine transformation, a new image encryption algorithm based on three dimensional sub-affine transformation was designed. By analyzing the constraints of three dimensional sub-affine transformation, according to the relation between variables and randomness of variables, a rapid construction method of three dimensional sub-affine transformation was given. Three color components of each pixel in the color space chose different ways to transform for achieving image scrambling, and its periodicity was discussed, for proposing the concept of singularity point and fake period. The experimental analysis shows that the algorithm has good effect of scrambling, larger key space, flexible encryption, and high security. And its diffusion and disturbance are ideal.

Key words: information security, digital image scrambling, three dimensional sub-affine transformation, periodicity, singularity point