On the resistance of Boolean functions against fast algebraic attacks

Abstract

Boolean functions with large algebraic immunity resist algebraic attacks to a certain degree, but they may not resist fast algebraic attacks (FAA's). It is necessary to study the resistance of Boolean functions against FAA's. In this paper, we localize the optimal resistance of Boolean functions against FAA's and introduce the concept of e-fast algebraic immunity (e-FAI) for n-variable Boolean functions against FAA's, where e is a positive integer and . We give the sufficient and necessary condition of e-FAI. With e-FAI the problem of deciding the resistance of an n-variable Boolean function against FAA's can be converted into the problem of observing the properties of one given matrix. An algorithm for deciding e-FAI and the optimal resistance against FAA's is also described. © 2012 Springer-Verlag.