基于复合混沌系统的数字图像加密研究

Research on Digital Image Encryption Based on Composite Chaotic System

引入两个混沌迭代子系统组成的复合混沌迭代系统,其动力学行为保持了各个混沌迭代子系统的特定行为,并且比单个子系统的动力学行为更为复杂。证明了复合混沌迭代系统的复合选择序列、复合混沌迭代系统的输出和单一子系统输出之间的关系。改进了复合混沌迭代系统的复合选择序列的产生方法,使得其子系统在被均匀选择的条件下,复合混沌迭代系统的不变分布密度为1,复合混沌迭代系统的输出在(0,1)空间的分布具有均匀性。如果再配以使输出二进制位独立同分布的转换算子,应用于数字图像加密等领域,其视觉效果和性能参数都有较大的提高,在通信、信息处理等领域的应用前景广阔。

Dynamic behaviors of composite chaotic iteration system retain all the special behaviors of each chaotic iteration subsystem and are more complicated than any single chaotic iteration subsystem. This paper proves the relations between the output of composite chaotic iteration system, chaotic iteration subsystem and the composite choosing sequences. If the uniformity with respect to composite choosing sequences is confirmed, it can guarantee that the invariant distribution density of composite chaotic iteration system is 1, which means the value in output space of （0,1） keeps uniform. And if the composite chaotic iteration system is also matched with a conversional operator with the attributions of independence and the same distribution, and applied to the province of digital image encryption, its visual effect and capability parameters have great improvements, it takes a great role in communication, information processing etc..