Paper 2004/284

ON THE DEGREE OF HOMOGENEOUS BENT FUNCTIONS

Qingshu Meng and Huanguo Zhang and Min Yang and Jingsong Cui

Abstract

It is well known that the degree of a $2m$-variable bent function is at most $m.$ However, the case in homogeneous bent functions is not clear. In this paper, it is proved that there is no homogeneous bent functions of degree $m$ in $2m$ variables when $m>3;$ there is no homogenous bent function of degree $m-1$ in 2m variables when $m>4;$ Generally, for any nonnegative integer $k$, there exists a positive integer $N$ such that when $m>N$, there is no homogeneous bent functions of degree $m-k$ in $2m$ variables. In other words, we get a tighter upper bound on the degree of homogeneous bent functions. A conjecture is proposed that for any positive integer $k>1$, there exists a positive integer $N$ such that when $m>N$, there exists homogeneous bent function of degree $k$ in $2m$ variables.

Note: a scholar told me one spelling error due to my unfamilarity to latex when i submitted this paper to eprint in 2004.