New Permutation Trinomials From Niho Exponents over Finite Fields with   Even Characteristic
  In this paper, a class of permutation trinomials of Niho type over finite fields with even characteristic is further investigated. New permutation trinomials from Niho exponents are obtained from linear fractional polynomials over finite fields, and it is shown that the presented results are the generalizations of some earlier works. 
Nian Li and Tor Helleseth
cs.IT math.IT