In this paper we concentrate on {\it efficient} slide attacks, whose time complexity is less than $2^n$. We present a number of new attacks that apply in scenarios in which previously known slide attacks are either inapplicable, or require at least $2^n$ operations. In particular, we present the first known slide attack on a Feistel construction with a {\it 3-round} self-similarity, and an attack with practical time complexity of $2^{40}$ on a 128-bit key variant of the GOST block cipher with {\it unknown} S-boxes. The best previously known attack on the same variant, with {\it known} S-boxes (by Courtois, 2014), has time complexity of $2^{91}$.
Category / Keywords: secret-key cryptography / Slide Attacks, Cryptanalysis, Recovering Unknown S-boxes, GOST, 3K-DES Date: received 23 Dec 2016 Contact author: orrd at cs haifa ac il Available format(s): PDF | BibTeX Citation Version: 20161230:194338 (All versions of this report) Short URL: ia.cr/2016/1177