FOURIER SPECTRA OF BINOMIAL APN FUNCTIONS.

In this paper we compute the Fourier spectra of some recently discovered binomial almost perfect nonlinear (APN) functions. One consequence of this is the determination of the nonlinearity of the functions, which measures their resistance to linear cryptanalysis. Another consequence is that certain error-correcting codes related to these functions have the same weight distribution as the 2-error-correcting Bose-Chaudury-Hocquenghem (BCH) code. Furthermore, for field extensions of F₂ of odd degree, our results provide an alternative proof of the APN property of the functions. [ABSTRACT FROM AUTHOR]