Security evaluation on Simeck against zero‐correlation linear cryptanalysis

Abstract

Since proposed by the National Security Agency in June 2013, two lightweight block ciphers-SIMON and SPECK have attracted the attention of cryptographers from all over the world. At CHES 2015, Simeck, a new block cipher inspired from both SIMON and SPECK is proposed, which is more compact and efficient. However, the security evaluation on Simeck against zero-correlation linear cryptanalysis seems missing from the specification. The main focus of this study is to fill this gap and evaluate the security level of Simeck against zero-correlation linear cryptanalysis. According to the authors' study, 11-, 13- and 15-round zero-correlation linear distinguishers on Simeck32/48/64 are proposed, respectively, then zero-correlation linear cryptanalysis on 21-, 24-, 28-round Simeck32/48/64 are first proposed. As far as they know, for Simeck32, their result is the best result up to date.