基于改进广义cat映射的彩色卫星图像加密算法

为了提高彩色卫星图像的加密效果,提出了一种基于改进广义cat映射的彩色卫星图像加密算法。该算法利用广义cat映射的构造思想,将离散广义cat映射的第一个变换表达式所对应的变换结果非线性的融入第二个变换表达式,利用改进广义cat映射对彩色卫星图像的三个色彩分量分别进行三轮置乱,然后利用复合混沌映射对置乱后的图像进行扩散。经过理论分析和仿真实验检测,该算法可以更好的改善图像的加密效果,具有密钥空间大、抗统计攻击能力强、密钥敏感性强等良好的性能,能够达到相应的安全水平。

Color Satellite Image Encryption Algorithm Based on Improved Generalized Cat Mapping

In order to improve encryption effect of color satellite image,in this paper,a color satellite image encryption algorithm based on improved generalized cat map is proposed; the idea of constructing the generalized cat mapping is used in this algorithm. The transformation of the corresponding first transform expression of discrete generalized cat mapping of the nonlinear transform into second, three color components of color images were three scrambled by using the improved generalized cat mapping; then the diffusion for scrambled image is carried out by using compound chaos mapping. Theoretical analysis and simulation results show that the algorithm can improve encryption effect of the image;it has a large space with a secret key,anti-statistical attack,good performance and strong sensitivity of the secret key and can achieve the appropriate level of safety.