多维零相关线性分析模型的改进及在23轮LBlock-s算法中的应用

发布时间：2018-03-10 23:50

本文选题：分组密码　切入点：LBlock-s　出处：《计算机学报》2017年05期 　论文类型：期刊论文

【摘要】：基于相关性为零的线性逼近的多维零相关线性密码分析是目前最重要的分组密码分析手段之一.该文主要对多维零相关线性分析模型的密钥恢复阶段进行了深入的研究,通过定义等价密钥的距离来刻画等价密钥在压缩表达式中的位置关系,进一步约简区分器候选集合同时优化密钥猜测顺序,从而改进了原有的多维零相关线性分析的攻击模型.改进的模型首先找到所有最长的多维零相关线性区分器,然后利用密钥编排算法求得密钥恢复阶段所涉及的独立猜测密钥量,以此筛选区分器候选集合.最后,根据等价密钥的距离对候选区分器进行再次筛选,同时得到相应的密钥猜测顺序.LBlock-s算法是CAESAR竞赛中所提交的认证加密算法LAC的核心分组算法.与Lblock算法不同,LBlock-s采用具有更快混淆速度的密钥编排算法.基于改进的优化模型,该文分析了该算法抵抗多维零相关线性攻击的能力.研究表明,攻击23轮LBlock-s算法所需的数据复杂度为2~(62.3)个选择明文,时间复杂度为2~(73.75)次23轮LBlock-s加密,存储复杂度为2~(56)字节.这是目前针对LBlock-s算法的最优攻击结果.
[Abstract]:Based on the correlation analysis of multidimensional approximation zero linear zero correlation linear cipher block cipher is the most important means of analysis. This paper mainly focuses on the multidimensional zero correlation linear analysis model of the key studied the recovery phase, position relation defined by equivalence key distance to describe the equivalent keys in the compression expression, further reduction distinguisher candidate set and optimize the key to improve the order of speculation, attack the original multidimensional analysis model of zero correlation linear. The improved model first finds all the longest dimension zero correlation linear distinguisher, and then use the key schedule algorithm independent key key recovery stage by speculation involved, to screen the candidate set is distinguished finally, according to the distance of the equivalent key candidate divider further screened, and get the key guessing sequence. LBlock-s algorithm is the core algorithm of packet encryption algorithm LAC presented in CAESAR competition. Different certification with the Lblock algorithm, LBlock-s uses a key schedule algorithm faster speed. Confusion based on the improved optimization model, this paper analyzes the ability of the algorithm against multidimensional zero correlation linear attack. The study shows that the attack on 23 round LBlock-s algorithm the required data complexity is 2~ (62.3) a chosen plaintext, the time complexity is 2~ (73.75) 23 round LBlock-s encryption, the storage complexity is 2~ (56 bytes). This is the LBlock-s algorithm for the optimal result of the attack.

【作者单位】：中国科学院软件研究所可信计算与信息保障实验室;中国科学院大学;
【基金】：国家“九七三”重点基础研究发展规划项目(2013CB338002) 国家自然科学基金(61272476,61232009,61202420)资助~~
【分类号】：TN918.1

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