On balanced binary sequences with two-level autocorrelation functions

Recently, Maschietti (Des., Codes Cryptogr., vol.14, p.89, 1998) constructed several families of (2/sup m/-1,2/sup m-1/-1,2/sup m-2/-1) cyclic difference sets from monomial hyperovals. In this correspondence, we consider the binary sequences associated to the difference sets constructed by Maschietti. We give algebraic proof of the fact that these sequences have two-level autocorrelation functions, also we discuss the linear spans of these sequences.