The Good lower bound of Second-order nonlinearity of a class of Boolean function
In this paper we find the lower bound of second-order nonlinearity of Boolean function fλ(x) = Trn 1 (λx p) with p = 22r + 2r + 1, λ ∈ F2r and n = 5r. It is also demonstrated that the lower bound obtained in this paper is much better than the lower bound obtained by Iwata-Kurosawa [14], and Gangopadhyay et al. (Theorem 1, [12]).