01▲A (6, 4) Vectorial Boolean Function With Nonlinearity 26 and the Maximum Nonlinearity for Six-Bit Permutations eprint.iacr.org Can a 6-bit S-box do better? This preprint says 6->4 maps hit 26, while permutations still top out at 24.bent-functionsboolean-functionscryptanalysiseprintnonlinearityreed-muller-codess-boxeswalsh-transform0 pts/pavelk/15 days ago/4 comments