Adding variables variation to Rainbow-like scheme to enhance its security level against MinRank attack

摘要

Rainbow is a very effective multivariate digital signature scheme proposed by J. Ding and D. Schmidt. In this paper, we define any scheme that has basic multilayer Rainbow structure as Rainbow-like scheme. Then, we propose a way to enhance Rainbow-like schemes' security level against MinRank attack. In our construction, we simply turn some of their first layers' Oil variables into Vinegar variables by adding corresponding quadratic terms. Copyright (c) 2014 John Wiley & Sons, Ltd.