Ciphers get their strength from the mathematical functions of confusion and
diffusion, also known as substitution and permutation. These were the basics of
classical cryptography and they are still the basic part of modern ciphers. In
block ciphers diffusion is achieved by the use of Maximum Distance Separable
(MDS) matrices. In this paper we present some methods for constructing dynamic
(and random) MDS matrices.Comment: Short paper at WISA'10, 201
