BLAKE抗线性化差分分析安全性研究  

Security Analysis of Resistance against Differential-linear Attack on BLAKE-32

作　　者：毛明[1] 贺强[1,2] 曾绍昆[1,2] 张珺[3] 

机构地区：[1]北京电子科技学院信息安全系,北京100070 [2]西安电子科技大学通信工程学院,西安710071 [3]北京邮电大学电子工程学院,北京100876

出　　处：《计算机科学》2011年第7期76-79,共4页Computer Science

摘　　要：基于模加、循环及异或运算的系统(ARX系统)通常被认为是设计密码算法的重要基础。在SHA-3第二轮候选算法中,BLAKE等杂凑函数基于该系统设计。通过对BLAKE-32中的模加运算进行线性化,分析了初始差分在各轮运算过程中的扩散情况,得出了初始状态字存在差分时各轮运算中差分的扩散特征。在此基础上,研究了多次加法运算的线性化逼近概率,并分析了线性化逼近方法对分析算法的有效性。研究表明,线性化情况下,部分初始差分字在BLAKE-32中的扩散效果并不理想,可以将BLAKE算法局部线性化后进行差分攻击。Hash function BLAKE is one of candidates for the second round SHA-3 competition,which is based on modu-lar addition,rotation and XOR that is called as ARX system commonly.It is a common belief that the mixture of the three operations gives a good primitive in designing cryptographic algorithm.By replacing modular addition with XOR,this paper researched linearization of ARX system in BLAKE-32 algorithm,then,analyzed differential diffusibility of the algorithm after linearization and exploited some diffusion characteristics,furthermore,researched the probability of linearapproximation of addition,and analyzed its validity on the algorithm.The result shows that differential spreading does not satisfy the designers＇ declaration.On account of ARX in BLAKE,differential attack can be applied on BLAKE by local linearizing its core function.

关 键 词：杂凑函数 ARX BLAKE算法 线性化 差分攻击 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]