Construction of Resilient Functions over a Finite Alphabet
Résumé
We extend the notions of correlation-immune functions and resilient functions to functions over any finite alphabet endowed with the structure of an Abelian group. Thus we generalize the results of Gopalakrishnan and Stinson as we give an orthogonal array characterization and a Fourier transform characterization for resilient functions over any finite alphabet. This leads to a generalization of some related cryptographic objects as perfect local randomizers. It also enables us to construct new resilient functions by composition of resilient functions of smaller order.