轻量级分组密码算法的设计和分析

Block cipher is the core technology to protect the confidentiality of data in the network age. However, traditional block cipher is difficult or impossible to be implemented on resource-constrained devices, such as RFID tag and sensor nodes. In order to satisfy the requirement of security in the new environment, the design and cryptanalysis of lightweight block ciphers become a hot issue on the field of cryptography. In this project, I will focus on this issue, build new automatic security evaluation models based on Mixed Integer Linear Programming (MILP) and Boolean Satisfiability Problem (SAT), and design a new lightweight block cipher with excellent software and hardware performances based on the new models above and my previous work. The detailed research contents are as follows: (1)build new automatic search model for impossible differential targeting lightweight block ciphers; (2)construct automatic evaluation model for security bound against differential cryptanalysis targeting ARX ciphers; (3) design a new lightweight block cipher, which has the advantage on software/hardware indicators comparing with other similar ciphers, while has the ability against all current attacks. All results in this project will provide new theoretical and technical supports for the design and cryptanalysis of lightweight block ciphers.

分组密码算法是保障网络时代信息机密性的核心密码技术。然而传统的分组密码算法不能很好的适应于RFID标签和传感器节点等资源受限设备。为应对新环境对安全性的需要，轻量级分组密码算法的设计与分析成为国际密码学领域的一个热点研究问题。本项目将围绕这一问题展开研究，基于混合线性整数规划技术和可满足性问题求解技术构建新的安全性自动化评估模型，并设计一个软硬件性能良好的ARX类轻量级分组密码算法。具体研究内容如下：（1）提出针对轻量级分组密码算法的不可能差分的自动化搜索模型；（2）构建ARX类算法的抗差分安全界的自动化评估模型；（3）基于新分析模型和已有研究工作，设计一个新的轻量级分组密码算法，在保证算法安全性的前提下，使其软硬件综合指标与国际同类算法相比较具有明显优势。本项目研究成果将为轻量级分组密码算法的设计和分析提供理论和技术支持。

分组密码算法是保障网络时代信息机密性的核心密码技术。然而传统的分组密码算法不能很好的适应于RFID标签和传感器节点等资源受限设备。为应对新环境对安全性的需要，轻量级分组密码算法的设计与分析成为国际密码学领域的一个热点研究问题。本项目围绕这一问题展开研究，提出了三个安全性分析和算法S盒构造模型：基于混合线性整数规划的不可能差分自动化搜索模型；基于可满足性问题的轻量级S盒构建模型；基于分层结构的8比特S盒构造模型。除此，本项目对现有的安全性分析模型进行改进，给出国际重要密码算法XOOFFF、2-GOST、GOST R和LBlock的最新攻击成果。最后，我们基于前期工作，设计完成一个分组密码算法和一个轻量级认证加密算法。前者荣获全国密码算法设计竞赛一等奖，后者已申请发明专利。本项目成果有利于推动中国密码事业的发展，为商用密码的标准化和党政密码的更新提供技术支持和备选方案。