Characterization of almost perfect nonlinear functions in terms of subfunctions
A. A. Gorodilova · Discrete Mathematics and Applications · 2016
Abstract The paper is concerned with combinatorial description of almost perfect nonlinear functions (APN-functions). A complete characterization of n -place APN-functions in terms of ( n − 1)-place subfunctions is obtained. An n -place function is shown to be an APN-function if and only if each of its ( n − 1)-place subfunctions is either an APN-function or has the differential uniformity 4 and the admissibility conditions hold. A detailed characterization of 2, 3 or 4-place APN-functions is presented.