Cryptology ePrint Archive: Report 2013/530

The Parallel-Cut Meet-In-The-Middle Attack

Ivica Nikolic and Lei Wang and Shuang Wu

Abstract: We propose a new type of meet-in-the-middle attack that splits the cryptographic primitive in parallel to the execution of the operations. The result of the division are two primitives that have smaller input sizes and thus require lower attack complexities. However, the division is not completely independent and the sub-primitives depend (output of one is the input for the other) mutually on a certain number of bits. When the number of such bits is relatively small, we show a technique based on three classical meet-in-the-middle attacks that can recover the secret key of the cipher faster than an exhaustive search. We apply our findings to the lightweight block cipher Klein and show attacks on 10/11/13 rounds of Klein-64/-80/-96. Our approach requires only one or two pairs of known plaintexts and always recovers the secret key.

Category / Keywords: secret-key cryptography / meet-in-the-middle attack, cryptanalysis, parallel-cut, block cipher, hash function, Klein

Date: received 25 Aug 2013, last revised 22 Sep 2013

Contact author: inikolic at ntu edu sg

Available format(s): PDF | BibTeX Citation

Version: 20130923:012036 (All versions of this report)

Short URL: ia.cr/2013/530

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