Improved Zero-Correlation Cryptanalysis on SIMON

Abstract

SIMON is a family of lightweight block ciphers publicly released by the NSA. Up to now, there have been many cryptanalytic results on it by means of differential, linear, impossible differential, integral, zero-correlation linear cryptanalysis and so forth. At INDOCRYPT 2014, Wang et al. gave zero-correlation attacks for 20-round SIMON32, 20-round SIMON48/72 and 21-round SIMON48/96. We investigate the security of whole family of SIMON by using zero-correlation linear cryptanalysis in this paper. For SIMON32 and SIMON48, we can attack one more round than the previous zero-correlation attacks given by Wang et al. We are the first one to give zero-correlation linear approximations of SIMON64, SIMON96 and SIMON128. These approximations are also utilized to attack the corresponding ciphers.