Theoretical analysis of η2 attack on RC6

Abstract

In this paper, we give a theoretical analysis of η2 attack proposed by Knudsen and Meier on the RC6 block cipher. To this end, we propose the method of security evaluation against η2 attack precisely including key dependency by introducing a method "Transition Matrix Computing." Previously, no theoretical security evaluation against η2 attack was known, it has been done by computer experiments. We should note that this is the first results that a theoretical evaluation against η2 attack is shown. © 2003 Springer-Verlag Berlin Heidelberg.