A note on the confusion coefficient of Boolean functions

Low confusion coefficient values can make side-channel attacks harder for vector Boolean functions in Block cipher. In this paper, we give new results of f ⊞ g, ⊡ ⊕ g and fg different respectively. And deduce a relationship on the sum-of-squares between one n-variable function two (n - 1)-variable decomposition functions. Finally, find that is affine invariant.