融合压缩感知的图像加密技术研究

So far, the two major branches in image encryption research include chaotic image encryption and optical image encryption, and both their development trends have become slow. However, the appearance of compressive sensing theory, and the hotter and hotter security study for compressive sensing, revives their development for new vitality. This project investigates the integration technique of image encryption based on compressive sensing. Specifically, (1) after performing lightweight image encryption, some appropriate compressive sensing techniques are fully excavated and then used for sampling, which realizes the robust coding of encrypted image; (2) under the precondition of not affecting the sampling performance of compressive sensing, some chaotic cryptographic features are embedded in compressive sensing and then used for sampling, which realizes simultaneous image sampling, compression and encryption; (3) some appropriate encryption algorithms are designed for the measurement values generated by compressive sensing by utilizing chaos theory or optical technology, which realizes the security guarantee for compressive sensing measurements; (4) the latter two aspects can be further combined，which realizes dual encryption for image compressive sensing, i.e., which achieves an organic integration of compressive sensing, chaotic theory and optical technique under the application background of image. This project will broaden the application sphere of compressive sensing, provide the new technical support for chaotic image encryption and optical image encryption, and promote the further development of image encryption research.

目前，图像加密研究领域的两大主流，混沌图像加密和光学图像加密，发展动态均略显沉寂。压缩感知理论的出现，以及其安全特性愈来愈热的研究,为图像加密技术的研究注入了新的发展活力。本项目旨在对融合压缩感知的图像加密技术进行系统地研究，研究内容有：（1）在图像轻度加密的基础上，充分挖掘出一些适配的压缩感知技术进行采样，实现密文图像的鲁棒编码；（2）在不影响压缩感知采样性能的前提下，将混沌密码学特性融入其中后再作用于图像，实现图像的同时采样、压缩和加密；（3）借助混沌理论或光学技术，对压缩感知采样图像产生的测量值设计适合的加密算法，实现测量值的安全保障；（4）后两个内容进一步缝合实现压缩感知采样图像时的双重加密,从而在图像的应用背景下，实现了压缩感知、混沌理论和光学技术的有机融合。本项目将拓宽压缩感知技术的应用范围，为混沌图像加密和光学图像加密提供新的技术支持，促进图像加密技术研究的更进一步发展。

图像加密的研究已有很多年了，其中研究非常广泛的两种加密技术是混沌理论和光学变换。混沌加密常使用轮加密架构，密文的微小改变将会导致解密图像严重受损甚至不可解，故可称之为敏感加密。而光学加密恰恰相反，即使密文丢失很多数据，仍然能够将原始图像恢复到一定的程度，故可称为鲁棒加密。这两大类加密方案各有优缺点，各有适用的环境。可是就目前研究现状而言，两者的研究进展都遇到了瓶颈，前者主要是因为混沌数字化后的退化现象严重，后者缘于光学要求极高的精密度，所以发展动态均略显沉寂。..压缩感知是一种采样和压缩同时进行的技术，与Nyquist标准相比，只需要对信号采样非常少量的数据，仍能精确恢复出原始信号。压缩感知理论的出现，为图像加密的研究注入了新的活力，因为它提供了一种新的思路，即实施安全的压缩感知，对图像实现同时性的压缩和加密。本项目对融合压缩感知的图像加密技术进行了系统的研究，从四个基本层面入手：先图像加密后压缩感知；先在压缩感知中嵌入密码特征后采样图像；先图像压缩感知后加密；在压缩感知中嵌入密码特征执行图像采样后再加密，分析设计出了一些新型的融合方案，有效地克服以上缺陷和不足，使得压缩感知和图像加密获得了进一步的发展研究。..受该项目资助共发表30余篇科技论文，其中20余篇SCI论文。相关成果发表在了IEEE Communications Surveys & Tutorials、IEEE Transactions on Big Data、IEEE Internet of Things Journal 、Nonlinear Dynamics、IEEE Transactions on Cybernetics、IEEE Multimedia、Neurocomputing、Signal Processing、Information Sciences、International Journal of Bifurcation and Chaos等国际著名期刊上。有4名博士生和4名研究生因参与本项目的实施很大地提升了科研素养。