S盒和P置换安全性指标评估方法的研究与比较

Research and Comparison on Security Evaluation Method of S⁃box and P⁃value Permutation

分组密码具有速度快、易于标准化和便于软硬件实现等特点,是信息与网络安全中实现数据加密和认证的核心体制。分组密码算法的思想是通过混淆和扩散来克服统计分析,由此引入了两个关键部件:S盒与P置换。S盒的安全指标主要有差分均匀度、非线性度、代数次数与代数项数、扩散性、严格雪崩性、代数免疫度,P置换的安全指标主要以矩阵分支数为主。针对S盒与P置换的安全指标,本文提出P置换新的评估算法,并与已有的评估算法进行比较分析,在此基础上,针对现行的多种S盒与P置换方案进行评估和比较分析,得出在安全性和实现效率最具优势的S盒和P置换方案。

As the core framework to realize data encryption and authentication in information and net⁃work security,block ciphers have the characteristics of fast speed,easy to standardize,convenient to implement with software and hardware,which overcome the statistical analysis through confusion and diffusion,thus inducing two key components of S⁃box and the P⁃value permutation.Security metrics of the S⁃box mainly include differential uniformity,nonlinearity,algebraic degree and algebraic terms number,diffusion,strict avalanche criterion,and algebraic immunity,and the security metric of the P⁃value permutation is matrix branch number.In this paper,for the security metrics of the S⁃box and the P⁃value permutation,a novel evaluation algorithm for the P⁃value permutation is proposed,and a com⁃parison with existing evaluation algorithms is presented,based on which,multiple S⁃box and the P⁃per⁃mutation schemes in use are evaluated and compared,and the scheme with highest security and effi⁃ciency is determined.