A family of permutation trinomials in ${\mathbb{F}}_{q^2}$

Daniele Bartoli, Marco Timpanella

Let $p>3$ and consider a prime power $q=p^h$. We completely characterize permutation polynomials of ${\mathbb{F}}_{q^2}$ of the type $f_{a,b}(X) = X(1 + aX^{q(q-1)} + bX^{2(q-1)}) \i…