Constructing new APN functions from known ones.
Lilya Budaghyan, Claude Carlet, Gregor Leander · IACR Cryptology ePrint Archive · 2007
We present a method for constructing new quadratic APN functions from known ones. Applying this method to the Gold power functions we construct an APN function x 3 + tr(x 9 ) over F2n. It is proven that in general this function is CCZinequivalent to the Gold functions (and therefore EA-inequivalent to power functions), to the inverse and Dobbertin mappings, and in the case n = 7 it is CCZinequivalent to all power mappings.