一种针对祖冲之算法的猜测决定攻击  

A guess and determine attack on ZUC algorithm

作　　者：赵跃华[1] 刘文山[1] 韩牟[1] 

机构地区：[1]江苏大学计算机科学与通信工程学院,江苏镇江212013

出　　处：《江苏大学学报（自然科学版）》2015年第5期578-582,共5页Journal of Jiangsu University：Natural Science Edition

基　　金：国家自然科学基金资助项目(61300229);中国博士后基金资助项目(2013M531283);江苏省博士后基金资助项目(1201037C);江苏省"六大人才高峰"计划项目(DZXX-012);江苏省高校自然科学基金资助项目(12KJD580002);江苏省研究生创新基金资助项目(KYLX-1057)

摘　　要：为了分析ZUC算法在抵御猜测决定攻击方面的安全性,针对ZUC算法在比特重组以及非线性函数中独特的16比特半字的运算,提出基于16比特半字的猜测决定攻击.该攻击方法首先将ZUC中的状态转换运算变换为半位的运算,将线性反馈移位寄存器中的每个状态分为上下半位,然后通过使用Viterbi-like算法计算出猜测决定攻击的基本点,根据已知的基本点状态和变换后的半位运算,决定出其他未知的状态,从而实现对内部状态的恢复.结果表明,这种猜测决定攻击计算复杂度为2398,所需数据量为6个32比特密钥字,该结果优于已有的针对ZUC的猜测决定攻击.To analyze the security of ZUC algorithm for resisting guess and determine attack,a guess and determine attack was proposed based on unique 16 bite half word for ZUC algorithm in half word operation. The operation of state transition was transformed to the half word operation,and every state in LFSR was divided into up and down half word. The basic point of the guess and determine attack was computed out by Viterbi-like algorithm. The other unknown states were determined according to the known state of basic points and the operation of half word to recover all internal states. The results show that the proposed attack on ZUC has a computational complexity of 2^398 and requires 6 key stream words,which is better than the previous guess and determine attack on ZUC.

关 键 词：3GPP ZUC 猜测决定攻击 密码分析 流密码 Viterbi-like算法 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]