新的低轮Keccak线性结构设计  

New design of linear structure for round-reduced Keccak

作　　者：刘晓强 韦永壮[2,3] 刘争红[1] LIU Xiaoqiang;WEI Yongzhuang;LIU Zhenghong(Guangxi Key Laboratory of Cryptography and Information Security (Guilin University of Electronic Technology),Guilin Guangxi 541004,China;Guangxi Key Laboratory of Wirekess Wideband Communication and Signal Processing (Guilin University of Electronic Technology),Guilin Guangxi 541004,China;Guangxi Colleges and Universities Key Laboratory of Cloud Computing and Complex Systems (Guilin University of Electronic Technology),Guilin Guangxi 541004,China)

机构地区：[1]广西密码学与信息安全重点实验室(桂林电子科技大学),广西桂林541004 [2]广西无线宽带通信与信号处理重点实验室(桂林电子科技大学),广西桂林541004 [3]广西高校云计算与复杂系统重点实验室(桂林电子科技大学),广西桂林541004

出　　处：《计算机应用》2018年第10期2934-2939,共6页journal of Computer Applications

基　　金：国家自然科学基金资助项目(61572148);广西无线宽带通信与信号处理重点实验室2016年主任基金资助项目(GXKL06160112)~~

摘　　要：针对Keccak算法S盒层线性分解的问题,提出一种新的线性结构构造方法,该方法主要基于Keccak算法S盒代数性质。首先,S盒层的输入比特需要固定部分约束条件,以确保状态数据经过这种线性结构仍具有线性关系;然后再结合中间相遇攻击的思想给出新的低轮Keccak算法零和区分器的构造方法。实验结果表明:新的顺1轮、逆1轮零和区分器可以完成目前理论上最好的15轮Keccak的区分攻击,且复杂度降低至2257;新的顺1轮、逆2轮零和区分器具有自由变量更多、区分攻击的组合方式更丰富等优点。Focusing on the linear decomposition of the S-box layer in Keccak algorithm,a new linear structure construction method was proposed based on the algebraic properties of the S-box.Firstly,to ensure the state data was still linear with that after this linear structure,some constraints about input bits of S-box needed to be fixed.Then,as an application of this technique,some new zero-sum distinguishers of round-reduced Keccak were constructed by combining the idea of meet-in-the-middle attack.The results show that a new 15-round distinguisher of Keccak is found,which extends 1-round forward and 1-round backward.This work is consistent with the best known ones and its complexity is reduced to 2 257.The new distinguisher,which extends 1-round forward and 2-round backward,has the advantages of more free variables and richer distinging attack combinations.

关 键 词：SHA-3 HASH算法 中间相遇 零和区分器 线性结构 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]