数字图像加密技术的安全性分析及其可证明安全理论研究

Theoretical security analysis for the digital image encryption is one of the most basic problems in the study field of the digital image encryption. It has a direct relationship with the development of the digital image encryption. This project aims to investigate the theoretical security of the image encryption algorithm, which mainly includes the image encryption algorithm for the space domain and compression domain respectively, according to the provable security analysis which is as the main approach. Specifically, we firstly make use of the differential cryptanalysis and linear cryptanalysis to study the security of image encryption algorithms for the space domain and the corresponding main structures. Secondly, we use the provable security theory to study the security of image encryption modes for the space domain. Thirdly, we take advantage of the provable security theory to study the security of encryption algorithms based on the Huffman coding and arithmetic coding. Our project focuses on the innovation from the research source. It is expected to achieve the breakthrough results in three aspects, namely, the theoretical security of the image encryption algorithm for the space domain and the corresponding structure for resisting the differential cryptanalysis and linear cryptanalysis, the study on the provable security of the image encryption mode for the space domain and the provable security analysis of the image encryptions based on the Huffman coding and arithmetic coding. Moreover, we expect to achieve the sufficient security condition about the encryption algorithms based on the Huffman coding and arithmetic coding which are secure against the chosen-plaintext attack. The study of our project can provide the theoretical basis and technical support from the security part for the design of the image encryption algorithm. Therefore, this project is of significance from the theoretical aspect and practical aspect.

数字图像加密技术的理论安全性分析是数字图像加密研究领域最基础的问题之一，它关系到数字图像加密研究的发展前景。本项目以两种主要图像加密算法即空域图像加密和压缩域图像加密算法为研究对象，以可证明安全分析为主要研究方法，探索图像加密算法的理论安全性。具体内容包括：研究空域图像加密算法及其整体结构对差分和线性分析的安全性；利用可证明安全理论研究空域图像加密模式的安全性；利用可证明安全理论研究基于哈夫曼和算术编码的加密算法的安全性。本项目注重源头创新，可望在空域图像加密算法及其整体结构对差分和线性分析的理论安全性、对空域图像加密模式的可证明安全研究、对基于哈夫曼和算术编码的加密算法的可证明安全分析3方面取得突破性成果，得到关于基于哈夫曼和算术编码对选择明文攻击安全的加密算法的充分安全条件。本项目的研究将为图像加密算法的设计提供安全性方面的理论基础和技术保障。因此，本项目具有重要的理论意义和实用价值。

针对图像数据的加密技术的研究一直以来都被认为是信息安全研究领域内一个重要的方向，这其中对相关加密算法的理论安全性分析又是最基础的研究问题之一，它能够在根本上保证加密算法的可行性。本项目以可用于加密图像数据的对称密钥加密算法为研究对象，研究了加密算法本身以及其相应整体结构的理论安全性问题。具体来说，研究了广义Feistel加密结构的理论安全性问题、Even-Mansour整体加密结构的理论安全性问题以及相对应的具体加密算法LBlock、TWINE和LED的安全性问题。针对这些研究问题，我们深入分析和调研了国内外的研究现状，提出了我们自己的改进方案和思路，撰写了多篇学术论文，并已在高质量的国际会议上发表了部分相关的学术成果。本项目的研究为对称密钥加密算法的分析提供了新的思路和方法，也为今后加密算法的设计和改进提供了一定的理论依据。