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演化密码是我国学者提出的一种新型密码.文中对演化密码对抗多重线性密码分析的能力进行研究,研究表明演化密码对抗多重线性攻击方面的能力高于普通固定算法密码.文中介绍了基于对数似然比(LLR)统计方法的两种多重线性密码分析方法,这两种方法利用多个线性逼近式分别扩展了Matsui最初提出的线性攻击算法1和算法2.在考察这两种算法的数据复杂度N、比特优势a,以及预期成功率PS三者关系的基础上,证明了在比特优势和预期成功率相同的条件下,攻击演化密码的数据复杂度大于攻击固定算法密码的数据复杂度,并论述了在数据复杂度N相同的情况下,攻击演化密码的时间复杂度和空间复杂度都明显高于攻击固定算法密码的情形.这表明演化密码在对抗多重线性攻击方面的安全性高于固定算法密码.
Evolutionary Cryptography is a new type of cryptography proposed by Chinese scholars.This paper studies the evolvement of cryptanalysis against multiple linear cryptanalysis, and shows that the ability of evolved cryptography against multiple linear attacks is higher than that of ordinary fixed cryptographic algorithms.In this paper, Two methods of multiple linear cryptanalysis based on LLR statistical methods, which use multiple linear approximations to extend Matsui’s original linear attack algorithm 1 and algorithm 2, respectively.2 After examining the data of these two algorithms Complexity N, bit advantage a, and expected success rate PS, it is proved that the data complexity of attack evolution cryptography is greater than that of attacking fixed algorithm cryptography under the condition of the same bit advantage and expected success rate , And discusses the case that attack-evolve password is both more time-consuming and complex in space than attack-fixed algorithm under the condition of the same data complexity N. This shows that evolved password is highly secure against multiple linear attacks Fixed algorithm password.