一种基于混合混沌序列的图像置乱加密算法  

An Image-scrambling Algorithm Based on Mixed Chaotic Sequences

作　　者：范延军[1] 孙燮华[1] 阎晓东[1] 郑林涛[1] 

机构地区：[1]中国计量学院计算机科学与技术系,杭州310034

出　　处：《中国图象图形学报》2006年第3期387-393,共7页Journal of Image and Graphics

摘　　要：由Logistic映射产生的混沌序列常被用来置乱加密数字图像,但迄今为止,在国内外有关文献中,均未提到由Logistic映射产生的混沌序列中存在“平凡密钥”和“拟平凡密钥”的现象。如果用“平凡密钥”和“拟平凡密钥”作为Logistic映射的初始值,则将无法产生可用于图像置乱的混沌序列,并且在Logistic映射中存在无穷多个“平凡密钥”和“拟平凡密钥”,这可能会导致对图像置乱加密无效,这是值得注意的问题.针对该问题,在对由Logistic映射产生的混沌序列中存在的“平凡密钥”和“拟平凡密钥”进行研究的基础上,提出了一种新的基于混合混沌序列的图像置乱加密算法,从而彻底解决了“平凡密钥”和“拟平凡密钥”对图像置乱加密无效的问题。The Logistic-Map chaotic sequence is often used to scramble and encrypt the digital images. In the former papers, the invalid-keys and the quasi invalid-keys existing in the Logistic-Map have not yet been discussed. If using the invalid-keys or the quasi invalid-keys as the initial value of the Logistic-Map, we can＇ t get the chaotic sequence to scramble the digital images. Furthermore, there are infinite invalid-keys and quasi invalid-keys in the Logistic-Map. So we should take the problems seriously. In this paper, the invalid-keys and the quasi invalid-keys existing in the Logistic-Map chaotic sequence are deeply discussed. Then, an image-scrambling algorithm based on mixed chaotic sequences is proposed. Using this algorithm, the invalidity of the invalid-keys and the quasi invalid-keys is avoided thoroughly.

关 键 词：混沌 混合混沌序列 排列变换 加密 小波变换 平凡密钥 拟平凡密钥 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]