Differential attacks on reduced round LILLIPUT

Abstract

In SAC 2013, Berger et al. defined Extended Generalized Feistel Networks (EGFN) and analyzed their security. Later, they proposed a cipher based on this structure: LILLIPUT. Impossible differential attacks and integral attacks have been mounted on LILLIPUT. We propose a tool which has found some classical, impossible and improbable differential attacks by using the variance method. It has highlighted unusual differential conditions which lead to efficient attacks according to the complexity. Moreover, it is the first time we apply the generic variance method to a concrete cipher.