S盒中仿射层对差分分析指标的影响

Influence of Affine Matrix in S-Boxes on Differential Cryptanalysis Index

S盒作为对称密码算法中的基础组件之一,其安全强度直接影响算法整体的好坏。考察轻量级算法PRINCE和PRESENT,通过给S盒加上不同的仿射矩阵,研究同一仿射等价类里不同S盒对2轮SPN结构的Anne界造成的影响。通过分析数据,从差分概率上界角度给出了部分比原S盒更好的仿射等价S盒,并发现仿射层的重量、分支数等参数会引起Anne界值的变化。上述结论可为PRINCE和PRESENT算法的S盒优化提供理论依据,同时可扩展到其他轻量级算法,为其S盒的选取提供在抗差分分析方面的参考。

S-boxes are important components in symmetric ciphers,whose safety strengths directly affect the quality of the whole structure.This paper investigate two lightweight ciphers:PRINCE and PRESENT.To analyze the influence of S-boxes in the same equivalence class on Anne bound of two round SPN,we add different affine matrix to these S-boxes.By analyzing the result,we provide S-boxes with better differential properties than the original one.Moreover,the differential brunch number and the weight of affine matrix will influence the new upper bound as well.All these results can be used in further analysis of S-box choice in PRINCE and PRESENT,and they can also be extended to other lightweight ciphers.