On almost perfect nonlinear mappings over F/sup n//sub 2/
Thierry Pierre Berger, Anne Canteaut, Pascale Charpin, Yann Laigle-Chapuy · 2005
We investigate some open problems on almost perfect nonlinear (APN) functions over a finite field of characteristic 2. We provide a new characterization of APN mappings and of APN permutations by means of their component functions. We also focus on the case of quadratic functions. Most notably, we prove that a class of quadratic functions cannot be APN. Our result strengthens the conjecture that all quadratic APN functions are power functions, up to equivalence