Generalized bent functions and their relation to Maiorana-McFarland class

In this paper, most of the known infinite classes of generalized bent functions are analyzed for their relation to the completed Maiorana-McFarland class. This is done using the criterion based on second-order derivatives of a function. In particular, it is shown that, unlike in the binary case, not all quadratic bent functions are EA-equivalent to a function of the Maiorana-McFarland type. This is the first attempt to rise this problem for the generalized bent functions.