  We study the nonlinearity and the weight of the rotation-symmetric (RotS)
functions defined by Pieprzyk and Qu. We give exact results for the
nonlinearity and weight of 2-degree RotS functions with the help of the
semi-bent functions and we give the generating function for the weight of the
3-degree RotS function. Based on the numerical examples and our observations we
state a conjecture on the nonlinearity and weight of the 3-degree RotS
functions.
