On the optimality of differential fault analyses on CLEFIA

Abstract

In 2012, several Differential Fault Analyses on the AES cipher were analyzed from an information-theoretic perspective. This analysis exposed whether or not the leaked information was fully exploited. We apply the same approach to all existing Differential Fault Analyses on the CLEFIA cipher. We show that only some of these attacks are already optimal. We improve those analyses which did not exploit all information. With one exception, all attacks against CLEFIA-128 reach the theoretical limit after our improvement. Our improvement of an attack against CLEFIA-192 and CLEFIA-256 reduces the number of fault injections to the lowest possible number reached so far.