3 research outputs found
Almost simple groups with socle acting on Steiner quadruple systems
Let , {}, a prime power, be a projective linear
simple group. We classify all Steiner quadruple systems admitting a group
with N \leq G \leq \Aut(N). In particular, we show that cannot act as a
group of automorphisms on any Steiner quadruple system for .Comment: 5 pages; to appear in: "Journal of Combinatorial Theory, Series A
Constructing Optimal Authentication Codes with Perfect Multi-fold Secrecy
We establish a construction of optimal authentication codes achieving perfect
multi-fold secrecy by means of combinatorial designs. This continues the
author's work (ISIT 2009) and answers an open question posed therein. As an
application, we present the first infinite class of optimal codes that provide
two-fold security against spoofing attacks and at the same time perfect two-
fold secrecy.Comment: 4 pages (double-column); to appear in Proc. 2010 International Zurich
Seminar on Communications (IZS 2010, Zurich