Cryptology ePrint Archive: Report 2017/1209

Improvements for Finding Impossible Differentials of Block Cipher Structures

Yiyuan Luo and Xuejia Lai

Abstract: In this paper we improve Wu and Wang's method for finding impossible differentials of block cipher structures. This improvement is more general than Wu and Wang's method that it can find more impossible differentials with less time. We apply it on Gen-CAST256, Misty, Gen-Skipjack, Four-Cell, Gen-MARS, SMS4, MIBS, Camellia*, LBlock, E2 and SNAKE block ciphers. All impossible differentials discovered by the algorithm are the same as Wu's method. Besides, for the 8-round MIBS block cipher, we find 4 new impossible differentials, which are not listed in Wu and Wang's results. The experiment results show that the improved algorithm can not only find more impossible differentials, but also largely reduce the search time.

Category / Keywords: block cipher; cryptanalysis; impossible differential; Automatic search

Original Publication (in the same form): Security and Communication Networks 2017

Date: received 18 Dec 2017, last revised 25 Dec 2017

Contact author: luoyiyuan777 at qq com

Available format(s): PDF | BibTeX Citation

Note: Minor Revision: some typos are corrected and more reference are added.

Version: 20171225:073549 (All versions of this report)

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