On the symmetric negabent boolean functions

Abstract

We study the negabent Boolean functions which are symmetric. The Boolean function which has equal absolute spectral values under the nega-Hadamard transform is called a negabent function. For a bent function, the absolute spectral values are the same under the Hadamard-Walsh transform. Unlike bent functions, negabent functions can exist on odd number of variables. Moreover, all the affine functions are negabent. We prove that a symmetric Boolean function is negabent if and only if it is affine. © 2009 Springer-Verlag.