基于混沌切换系统与余弦数量变换的图像加密  

Image encryption algorithm based on chaotic switching system and cosine number transform

作　　者：马建明[1] 高正平[2] 任兴东 

机构地区：[1]四川传媒学院数字媒体技术系,四川成都611730 [2]电子科技大学微电子与固体电子学院,四川成都611731 [3]四川工商职业技术学院信息工程系,四川成都611830

出　　处：《计算机工程与设计》2016年第9期2490-2496,共7页Computer Engineering and Design

摘　　要：当前图像加密算法因存在舍入误差,其解密图像存在失真问题,且其置乱结构为单向扰乱,造成算法的安全性不佳,缺乏图像内容认证功能等不足,为此提出双向置乱耦合余弦数量变换的抗失真图像加密技术。设计组合混沌切换系统,依据控制输出值生成1D混合数组,定义双向置乱结构,对明文完成正反向扫描操作,提高其置乱度;将置乱密文分割为子块,定义2D余弦数量变换机制,对其完成扩散,将扩散子块重组成密文;借助Hash认证函数,通过验证置乱与解密图像的Hash值,完成图像完整性检测。实验结果表明,与当前图像加密技术相比,该算法具备真伪认证功能,具有更高的安全性能与更低的失真度。To solve these defects such as big distortion existing in decrypted image induced by round-off errors,and poor security of algorithm caused by low permutation degree in current image encryption algorithms,the image encryption algorithm based on two directions scrambling coupled with cosine number transform was proposed.The two direction permutation structure was constructed by Hankel theory to finish the positive and reverse scan operation for changing the pixel position to increase the scrambling degree.The scrambling cipher was divided into sub-blocks,and these sub-blocks were diffused by introducing cosine number transform.And the diffusion sub-images were reorganized into cipher.According to the Hash authentication function,the image integrity was detected.Experimental results show that the proposed algorithm has the authentication function,and has better security performance and lower distortion degree compared with the current image encryption technology.

关 键 词：图像加密 双向置乱 组合切换混沌系统 余弦数量变换 Hash认证 失真度 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]