摘要
代数攻击是近年来兴起的一种有效而有趣的攻击方法[2]之一,被成功地应用于一些基于LFSR的流密码系统中,对流密码体制产生了巨大影响,众多密码工作者在代数攻击中求解多变元超定方程组求解、零化子的构造等方面都做了比较有效的研究。为了抵抗代数攻击,Meier等人[4]引入度量布尔函数安全性的新指标——代数免疫。代数免疫的提出给密码函数的分析和设计提出了新的课题[5]。该文介绍了一种具有最高代数免疫阶的非对称布尔函数的构造,这类构造最初由密码爱好者在2005年快速软体加密国际研讨会上做了简单介绍,但没有进行深入分析。该文研究证明了该类函数具有n个变量的时候函数具有最大可能的代数免疫阶为,是一类具有最高可能代数免疫阶的布尔函数。该文的最后研究了这类函数的代数阶、汉明重量,非线性度、Walsh谱等密码学特性。
Arising in recent years, algebraic attack is regarded as one of effective and pervasive attack methods. The method, which has been applied successfully in stream ciphers system based on LFSR, has significant influence on the mechanism of stream ciphers system. A great many of researches have been done to make contribution to the study of algebraic attack in terms of solving over-determined equations and the formation of annihilator. In order to resist algebraic attack, Meier introduced the concept of algebraic immunity which measures the security of Boolean Functions. The proposition of algebraic immunity takes the analysis and design of cryptographic function to a new level..In this paper, the construction of asymmetric Boolean Functions with highest algebraic immune order, which was first introduced on Indocrypt 2004 and FSE 2005 by anonymous reviewers , is proposed. It is proved in this paper that the functions have the possible highest algebraic immunity order when it contains variables with the number of n. In the end, the cryptography characteristics of the functions, including algebraic order, hamming weights and nonlinearity as well as the Walsh spectrum are analyzed and studied.
出处
《计算机安全》
2008年第10期44-47,共4页
Network & Computer Security
