摘要
很多基于混沌的映射数字图像加密算法都采用了量化策略,而量化后,其映射能否保持混沌的性质仍是一个未知数。在有限精度下,其映射会产生循环或收敛于不动点,与理想的密度函数分布背道而弛;提出了一种新的基于混沌映射的加密算法,该算法不需要对轨道分布具有先验知识,所以可以选用任何一个混沌模型,这极大地扩展了算法的密码空间、大大减少了混沌映射迭代次数并能很好地利用混沌的特性;同时还引入了广义面包师分割的思想,进一步提高密钥的空间、增强算法的安全。对所提出的算法进行了安全分析,实验结果表明:该算法具有对密钥敏感、密钥空间大、加密后像素分布均匀等特点,可有效地保障加密图像的安全。
Many digital image encryption algorithms based on chaotic map were presented; most of them use the quantization of coefficients. In finite precision, chaotic map will generate a circulation or an unmovable point, which does not accord with perfect density distributing function. This paper proposes a new encryption algorithm based on chaotic map without transcendental knowledge of orbit distributing. So that people can choose any chaos model, which extends the key space of algorithm. The algorithm reduces iterative number and makes full use of chaotic property of map. This paper also introduces the segmentation mechanism of general baker transformation, which enhances the key space and security of algorithm. The experiment shows that it has the property of key sensitivity, high key space and pixel distributing uniformity.
出处
《中山大学学报（自然科学版）》
CAS
CSCD
北大核心
2004年第A02期29-33,共5页
Acta Scientiarum Naturalium Universitatis Sunyatseni
基金
国家973计划资助项目(2002CB312104)
国家自然科学基金资助项目(60133020)
北京市科技发展计划资助项目(KM200310009027)
关键词
混沌映射
排列
图像加密
chaotic map
arrangement
image encryption
