The compositional inverse of a class of bilinear permutation polynomials over finite fields of characteristic 2

Abstract

A class of bilinear permutation polynomials over a finite field of characteristic 2 was constructed in a recursive manner recently which involved some other constructions as special cases. We determine the compositional inverses of them based on a direct sum decomposition of the finite field. The result generalizes that in [R.S. Coulter, M. Henderson, The compositional inverse of a class of permutation polynomials over a finite field, Bull. Austral. Math. Soc. 65 (2002) 521-526].