Investigations on <i>c</i>-Bent₄ Functions via the Unitary Transform and <i>c</i>-Correlation Functions

Abstract

In this paper, some properties of Boolean functions via the unitary transform and 𝑐-correlation functions are presented. Based on the unitary transform, we present two classes of secondary constructions for 𝑐-bent 4 functions. Also, by using the 𝑐-correlation functions, a direct link between 𝑐-autocorrelation function and the unitary transform of Boolean functions is provided, and the relationship among 𝑐-crosscorrelation functions of arbitrary four Boolean functions can be obtained.