基于优化耦合映像格子的比特级图像加密方法

Bit-Level Image Encryption Method Based on Optimized Coupled Map Lattice

现有的比特级图像加密方法通常按照图像数据采集、图像数据分解、图像数据加密这3个相对独立的步骤进行设计,加密效率难以提高。为了在保证安全性的前提下解决这一问题,研究并改进了Logistic映射,提出一种优化Logistic映射。利用此映射进一步改善了耦合映像格子系统的混沌特性。此外,利用优化后的耦合映像格子和压缩感知技术设计了一种比特级数字图像加密方法,将现有比特级图像加密方法中3个相对独立的步骤合而为一,实现了在图像数据采集的同时即完成比特级的信息分解与加密。理论分析和仿真实验结果表明,该方法在保证安全性的同时提高了现有比特级图像加密系统的运行效率。

The existing bit-level image encryption methods are usually designed according to the three relatively independent steps of image data collection,data decomposition and encryption,which causes low efficiency.In order to solve this problem without compromising security,Logistic map was studied and then OLM(Optimized Logistic Map)was proposed to improve the performance of chaotic map as well as the corresponding CML(Coupled Map Lattice).Besides,a bit-level image encryption method was designed by applying OCML(Optimized Coupled Map Lattice)and CS(Compressive Sensing)technologies.It combines three independent steps in encryption methods,which helps to realize the decomposition and encryption of bit-level information during the measurement process.Theoretical analysis and simulation results reveal that the proposed method could improve the efficiency of existing bit-level image encryption system while ensuring security.