Recursion orders for weights of Boolean cubic rotation symmetric functions

Abstract

Rotation symmetric (RS) Boolean functions have been extensively studied in recent years because of their applications in cryptography. In cryptographic applications, it is usually important to know the weight of the functions, so much research has been done on the problem of determining such weights. Recently it was proved that for cubic RS functions in n variables generated by a single monomial, the weights of the functions as n increases satisfy a linear recursion. Furthermore, explicit methods were found for generating these recursions and the initial values needed to use the recursions. It is important to be able to compute the order of these recursions without needing to determine all of the coefficients. This paper gives a technique for doing that in many cases, based on a new notion of towers of RS Boolean functions.