Linear hulls with correlation zero and linear cryptanalysis of block ciphers
Linear hulls with correlation zero and linear cryptanalysis of block ciphers
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DOI：
10.1007/s10623-012-9697-z
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发表时间：
2014-03-01
影响因子：
1.6
通讯作者：
Rijmen, Vincent
中科院分区：
文献类型：
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作者：
Bogdanov, Andrey;Rijmen, Vincent
线性密码分析与差分密码分析沿着，是评估分组密码安全性的重要工具。本文介绍了线性密码分析的一种新的扩展：零相关线性密码分析，一种适用于许多分组密码构造的技术。它基于线性近似，相关值恰好为零。对于一个n比特的置换，提出了一个复杂度为2（n-1）的相关性精确计算算法。非平凡的零相关线性近似证明了各种块密码结构，包括AES，平衡Feistel网络，Skipjack，CLEFIA和CAST 256。作为示例，使用零相关线性密码分析，对AES-192和AES-256的6轮以及CLEFIA-256的13轮进行了密钥恢复攻击。
Linear cryptanalysis, along with differential cryptanalysis, is an important tool to evaluate the security of block ciphers. This work introduces a novel extension of linear cryptanalysis: zero-correlation linear cryptanalysis, a technique applicable to many block cipher constructions. It is based on linear approximations with a correlation value of exactly zero. For a permutation on n bits, an algorithm of complexity 2 (n-1) is proposed for the exact evaluation of correlation. Non-trivial zero-correlation linear approximations are demonstrated for various block cipher structures including AES, balanced Feistel networks, Skipjack, CLEFIA, and CAST256. As an example, using the zero-correlation linear cryptanalysis, a key-recovery attack is shown on 6 rounds of AES-192 and AES-256 as well as 13 rounds of CLEFIA-256.