The characterization of hyper-bent function with multiple trace terms in the extension field

TL;DR

This paper characterizes hyper-bent functions with multiple trace terms over extension fields, solving an open problem by linking hyper-bentness to Dillon-like exponents and hyperelliptic curve properties.

Contribution

It provides a complete characterization of hyper-bent functions with multiple trace terms using Dillon-like exponents and hyperelliptic curve theorems, addressing an open problem.

Findings

Hyper-bentness characterized via Dillon-like exponents.

Application of Möbius transformation and hyperelliptic curves.

Solution to an open problem in hyper-bent function classification.

Abstract

Bent functions are maximally nonlinear Boolean functions with an even number of variables, which include a subclass of functions, the so-called hyper-bent functions whose properties are stronger than bent functions and a complete classification of hyper-bent functions is elusive and inavailable.~In this paper,~we solve an open problem of Mesnager that describes hyper-bentness of hyper-bent functions with multiple trace terms via Dillon-like exponents with coefficients in the extension field~$\mathbb{F}_{2^{2m}}$~of this field~$\mathbb{F}_{2^{m}}$. By applying M\"{o}bius transformation and the theorems of hyperelliptic curves, hyper-bentness of these functions are successfully characterized in this field~$\mathbb{F}_{2^{2m}}$ with~$m$~odd integer.