分组密码代数攻击及构造代数免疫S盒

项目名称： 分组密码代数攻击及构造代数免疫S盒

项目编号： No.61272465

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 自动化技术、计算机技术

项目作者： 祁传达

作者单位： 信阳师范学院

项目金额： 52万元

中文摘要： 由于很多密码算法在设计时没有考虑到超定多元高次方程组的可解性问题，随着较为有效的求解方程组的方法的出现，代数攻击越来越受到人们的重视。目前序列密码Toyocrypt、LILI-128、E0、公钥密码HFE、分组密码6圈的DES、Keeloq相继被代数攻击所攻破，代数攻击在分组密码AES、Serpent、SMS4的分析中也有出色的表现。 本课题瞄准AES、SMS4和一些典型的轻量级分组密码算法中唯一非线性变换S盒的代数结构，在不同数域上对加密算法实施代数攻击，现有的研究表明，我们攻击方法的计算复杂性低于目前已知的公开成果。进一步研究具有针对性的求解超定多元高次方程组的方法是本项目的研究重点之一。 代数攻击方法的出现必然导致对S盒代数免疫问题的研究，密码设计者迫切需要能抵抗代数攻击的S盒设计新准则的出现。S盒代数免疫研究是本课题的另一研究重点。

中文关键词： 代数攻击；代数免疫；S-盒；分组密码；密码函数

英文摘要： As cryptographer designed many cipher algorithms without considering the solvability problems of overdetermined nonlinear equations of higher order before. Recently, with the appearance of effective methods of solving these equations, algebraic attacks have received more and more attention. Till now, stream cipher such as Toyocrypt, LILI-128, E0 and public key cipher HFE and block cipher such as KeeLoq, six rounds DES are broken by algebraic attacks one by one, which also do a good job in the analysis of block cipher such as AES, Serpent, SMS4. The project focuses on the algebraic structure of S-box which is based on the only one nonlinear transformation in the block cipher such as AES ,SMS4 and some typical lightweight block cipher and imposes algebraic attacks on encryption algorithm in different number fields . According to the results of research, our methods of attacks are better than those have been attained. Therefore, further studying the methods of solving overdetermined higher order equations is the key part of the project. In order to resist algebraic attacks, S-box algebraic immunity has been proposed. A new cryptographic properties of S-box are urgently needed. So, S-box algebraic immunity is also the major focus of the project.

英文关键词： Algebraic attacks；Algebraic immunity；S-box；block cipher；Cryptographic function