Security Analysis of Lightweight loT Encryption Algorithms: SIMON and SIMECK

This paper presents the differential cryptanalysis of two lightweight ciphers, namely, SIMON and SIMECK. The first cipher SIMON was presented by the U.S. National Security Agency in 2013 and the second one SIMECK was presented by researchers from the University of Waterloo, Canada in 2015. Both block ciphers belong to the lightweight encryption family that relies on the Feistel structure. The primary goal of making a differential attack is finding a high probability differential characteristic (path) for the cipher. However, finding a differential characteristic in a limited amount of time is the most challenging and take several hours, which can possibly be reduced by a heuristic approach. This paper used nested tree search-based methods to find differential paths and presented a state of art results but in reduced time and simpler framework.