An algorithm for computing the upper bound for non-minimum weight differentials in 2-round LSX-ciphers

We describe some approaches to upper bounding the non-minimum weight differentials (EDP) and linear hulls (ELP) in 2-round LSX-cipher. We propose a dynamic programming algorithm to solve this problem. For 2-round Kuznyechik the nontrivial upper bounds on all differentials (linear hulls) with 18 and 19 active S-boxes are obtained. These estimates are also holds for other differentials (linear hulls) with a larger number of active S-boxes.