The strict avalanche criterion: Spectral properties of boolean functions and an extended definition

Abstract

A necessary and sufficient condition on the Walsh-spectrum of a boolean function is given, which implies that this function fulfills the Strict Avalanche Crit,erion. This condition is shown to be fWed for a class of functions exhibiting simple spectral symmetries. Finally, an extended definition of the Strict Avalanche Criterion is proposed and the corresponding spectral characterization is derived.