## Cryptology ePrint Archive: Report 2009/502

On second order nonlinearities of cubic monomial Boolean functions

Abstract: We study cubic monomial Boolean functions of the form $Tr_1^n(\mu x^{2^i+2^j+1})$ where $\mu \in \mathbb{F}_{2^n}$. We prove that the functions of this form do not have any affine derivative. A lower bound on the second order nonlinearities of these functions is also derived.