电子学报 ›› 2006, Vol. 34 ›› Issue (10): 1799-1802.

• 论文 • 上一篇    下一篇

非平衡Feistel网络的线性可证明安全性的进一步分析

王念平, 金晨辉, 余昭平   

  1. 解放军信息工程大学电子技术学院,河南郑州 450004
  • 收稿日期:2005-03-15 修回日期:2006-07-08 出版日期:2006-10-25 发布日期:2006-10-25

Furthermore Analyses of Linear Provable Security for a Class of Unbalanced Feistel Networks

WANG Nian-ping, JIN Chen-hui, YU Zhao-ping   

  1. Institute of Electronic Technology,the PLA Information Engineering University,Zhengzhou,Henan 450004,China
  • Received:2005-03-15 Revised:2006-07-08 Online:2006-10-25 Published:2006-10-25

摘要: 线性密码分析已成为分组密码最主要的密码分析方法之一.基于此,本文深入研究了一类非平衡Feistel网络的线性可证明安全性.设LP为该非平衡Feistel网络的轮函数F的线性偏差的最大值,本文从非平衡Feistel网络的线性偏差的结构形式入手,在轮子密钥是相互独立且均匀分布的假设下,证明了当轮数不少于m轮时,该非平衡Feistel网络的线性偏差关于密钥的平方均值的上界为LP的平方;当轮数不少于2m轮时,证明了该非平衡Feistel网络的线性偏差关于密钥的平方均值的上界为LP四次方的2倍.

关键词: 非平衡Feistel网络, 线性可证明安全性, 线性偏差关于密钥的平方均值, 上界

Abstract: Linear Cryptanalysis is one of the most important attacks on block ciphers.In this paper,the linear provable security for a class of unbalanced Feistel networks is investigated deeply.Using the structure of linear deviation,we prove that the upper bound of r-round(r≥m) linear hull probabilities are bounded by LP×LP and r-round(r≥2m) linear hull probabilities are bounded by 2(LP× LP×LP×LP) when the maximal linear hull probabilities of round function is LP and rounds keys are independent and uniformly random.

Key words: unbalanced Feistel networks, the linear provable security, linear hull probabilities, upper bounds

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