Cryptanalysis of White-Box DES Implementations with Arbitrary External Encodings
Cryptanalysis of White-Box DES Implementations with Arbitrary External Encodings
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DOI：
10.1007/978-3-540-77360-3_17
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发表时间：
2007-08
期刊：
影响因子：
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通讯作者：
B. Wyseur;Wil Michiels;Paul Gorissen;B. Preneel
中科院分区：
文献类型：
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作者：
B. Wyseur;Wil Michiels;Paul Gorissen;B. Preneel
在DRM 2002上，Chowet al. [4]提出了一种实现DES分组密码的方法，使得在白盒攻击环境中难以提取嵌入的秘密密钥。在这样的上下文中，攻击者可以完全访问实现及其执行环境。为了提供额外的安全级别，Chowet等人引入了一种用外部编码屏蔽的实现，并由Link和Neumann [10]改进。在本文中，我们提出了一个算法来提取这样的白盒DES实现的秘密密钥。密码分析是对混淆轮的差分攻击，并且无论应用的屏蔽外部编码如何都有效。密码分析的平均时间复杂度为214，空间复杂度可以忽略不计。
At DRM 2002, Chowet al.[4] presented a method for implementing the DES block cipher such that it becomes hard to extract the embedded secret key in a white-box attack context. In such a context, an attacker has full access to the implementation and its execution environment. In order to provide an extra level of security, an implementation shielded with external encodings was introduced by Chowet al.and improved by Link and Neumann [10]. In this paper, we present an algorithm to extract the secret key from such white-box DES implementations. The cryptanalysis is a differential attack on obfuscated rounds, and works regardless of the shielding external encodings that are applied. The cryptanalysis has a average time complexity of 214and a negligible space complexity.