Paper 2015/588

An analysis of the $C$ class of bent functions

Bimal Mandal, Pantelimon Stanica, Sugata Gangopadhyay, and Enes Pasalic

Abstract

Two (so-called $C,D$) classes of permutation-based bent Boolean functions were introduced by Carlet two decades ago, but without specifying some explicit construction methods for their construction (apart from the subclass $D_0$). In this article, we look in more detail at the $C$ class, and derive some existence and nonexistence results concerning the bent functions in the $C$ class for many of the known classes of permutations over ${\mathbb{F}}_{2^n}$. Most importantly, the existence results induce generic methods of constructing bent functions in class $C$ which possibly do not belong to the completed Maiorana-McFarland class. The question whether the specific permutations and related subspaces we identify in this article indeed give bent functions outside the completed Maiorana-McFarland class remains open.