Linear And Differential Analysis Of Simplified Kuznyechik Cipher

We presented a paper with the description of simplified Kuznyechik ciphers at SIN 2017 conference previous year [9]. We introduced two ciphers in [9]. The first one was designed for teaching general principles of Kuznyechik. The second one was designed for modeling different attacks in order to understand which ones need more research with regard to original Kuznyechik. In this paper we propose to consider the approaches of linear and differential cryptanalysis to the second simplified version. In order to achieve this, we investigate linear and differential properties of the cipher and find their particular features. We present an algorithm of building multi-round characteristics that engage as many non-zero blocks as possible for the differential analysis. As to the linear cryptanalysis, we consider possible ways to build efficient linear statistical analogs. We find maximal possible number of rounds for which the considered attacks are applicable.