International Association
for Cryptologic Research

Obtainment of exact value or high lower bound on the $r$-th order nonlinearity of Boolean function is a very complicated problem (especial if $r > 1$). In a number of papers lower bounds on the $r$-th order nonlinearity of Boolean function via its algebraic immunity were obtain for different $r$. This bounds is rather high for function with maximum near maximum possible algebraic immunity. In this paper we prove theorem, which try to obtain rather high lower bound on the $r$-th order nonlinearity for many functions with small algebraic immunity.