(1) Department of Pure Mathematics, The University of Adelaide, Adelaide, 5005, Australia.;(2) Department of Mathematics, Royal Holloway, University of London Egham, Surrey, TW20 0EX, United Kingdom
Abstract:
We consider authentication/secrecy schemes from the information theoretic approach. We extend results on unconditionally secure authentication schemes and then consider unconditionally secure authentication schemes that offer perfect L-fold secrecy. We consider both ordered and unordered secrecy. We establish entropy bounds on the encoding rules for authentication schemes with these types of secrecy. We provide some combinatorial characterizations and constructions for authentication schemes having perfect L-fold secrecy that meet these bounds.