Dynamic GOST

Abstract

GOST is a block algorithm which was adopted as a standard by the former Soviet Union. Because it keeps a lot of secret information, including S-boxes, the algorithm is secure and easy to understand. In this article, we propose a variant of COST, called dynamic COST, in which permutations are applied. With the permutation information securely kept: the new version of COST is more secure and better to withstand differential and linear attacks.