Cryptology ePrint Archive: Report 2014/860
Differential Factors: Improved Attacks on SERPENT
Cihangir Tezcan and Ferruh Özbudak
Abstract: A differential attack tries to capture the round keys corresponding to the S-boxes activated by a differential. In this work, we show that for a fixed output difference of an S-box, it may not be possible to distinguish the guessed keys that have a specific difference. We introduce these differences as differential factors. Existence of differential factors can reduce the time complexity of differential attacks and as an example we show that the 10, 11, and 12-round differential-linear attacks of Dunkelman et al. on SERPENT can actually be performed with time complexities reduced by a factor of 4, 4, and 8, respectively.
Category / Keywords: secret-key cryptography / S-box, differential factor, Serpent, differential-linear attack
Original Publication (in the same form): Lightsec 2014
Date: received 20 Oct 2014, last revised 2 Nov 2014
Contact author: cihangir at metu edu tr
Available format(s): PDF | BibTeX Citation
Note: Some typos are corrected.
Version: 20141102:103856 (All versions of this report)
Short URL: ia.cr/2014/860
Discussion forum: Show discussion | Start new discussion
[ Cryptology ePrint archive ]