On the affine classification of cubic bent functions
We consider cubic boolean bent functions, each cubic monomial of which contains the same variable. We investigate canonical forms of these functions under affine transformations of variables. In particular, we refine the affine classification of cubic bent functions of 8 variables.
Exponentiation in finite fields of characteristic 2 is proposed to construct large bijective S-boxes of block ciphers. We obtain some properties of the exponential S-boxes that are related to differential, higher order differential, and linear cryptanalysis methods.