330 research outputs found
Combinatorial Bounds and Characterizations of Splitting Authentication Codes
We present several generalizations of results for splitting authentication
codes by studying the aspect of multi-fold security. As the two primary
results, we prove a combinatorial lower bound on the number of encoding rules
and a combinatorial characterization of optimal splitting authentication codes
that are multi-fold secure against spoofing attacks. The characterization is
based on a new type of combinatorial designs, which we introduce and for which
basic necessary conditions are given regarding their existence.Comment: 13 pages; to appear in "Cryptography and Communications
Information Theoretic Authentication and Secrecy Codes in the Splitting Model
In the splitting model, information theoretic authentication codes allow
non-deterministic encoding, that is, several messages can be used to
communicate a particular plaintext. Certain applications require that the
aspect of secrecy should hold simultaneously. Ogata-Kurosawa-Stinson-Saido
(2004) have constructed optimal splitting authentication codes achieving
perfect secrecy for the special case when the number of keys equals the number
of messages. In this paper, we establish a construction method for optimal
splitting authentication codes with perfect secrecy in the more general case
when the number of keys may differ from the number of messages. To the best
knowledge, this is the first result of this type.Comment: 4 pages (double-column); to appear in Proc. 2012 International Zurich
Seminar on Communications (IZS 2012, Zurich
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
On the equivalence of authentication codes and robust (2,2)-threshold schemes
In this paper, we show a "direct" equivalence between certain authentication
codes and robust secret sharing schemes. It was previously known that
authentication codes and robust secret sharing schemes are closely related to
similar types of designs, but direct equivalences had not been considered in
the literature. Our new equivalences motivate the consideration of a certain
"key-substitution attack." We study this attack and analyze it in the setting
of "dual authentication codes." We also show how this viewpoint provides a nice
way to prove properties and generalizations of some known constructions
Disjoint difference families and their applications
Difference sets and their generalisations to difference families arise from the study of designs and many other applications. Here we give a brief survey of some of these applications, noting in particular the diverse definitions of difference families and the variations in priorities in constructions. We propose a definition of disjoint difference families that encompasses these variations and allows a comparison of the similarities and disparities. We then focus on two constructions of disjoint difference families arising from frequency hopping sequences and showed that they are in fact the same. We conclude with a discussion of the notion of equivalence for frequency hopping sequences and for disjoint difference families
On the equivalence of authentication codes and robust (2,2)-threshold schemes
In this paper, we show a “direct” equivalence between certain authentication codes and robust secret sharing schemes. It was previously known that authentication codes and robust secret sharing schemes are closely related to similar types of designs, but direct equivalences had not been considered in the literature. Our new equivalences motivate the consideration of a certain “key-substitution attack.” We study this attack and analyze it in the setting of “dual authentication codes.” We also show how this viewpoint provides a nice way to prove properties and generalizations of some known constructions
Perfect Secrecy Systems Immune to Spoofing Attacks
We present novel perfect secrecy systems that provide immunity to spoofing
attacks under equiprobable source probability distributions. On the theoretical
side, relying on an existence result for -designs by Teirlinck, our
construction method constructively generates systems that can reach an
arbitrary high level of security. On the practical side, we obtain, via cyclic
difference families, very efficient constructions of new optimal systems that
are onefold secure against spoofing. Moreover, we construct, by means of
-designs for large values of , the first near-optimal systems that are 5-
and 6-fold secure as well as further systems with a feasible number of keys
that are 7-fold secure against spoofing. We apply our results furthermore to a
recently extended authentication model, where the opponent has access to a
verification oracle. We obtain this way novel perfect secrecy systems with
immunity to spoofing in the verification oracle model.Comment: 10 pages (double-column); to appear in "International Journal of
Information Security
Existence of APAV(q,k) with q a prime power ≡5(mod8) and k≡1(mod4)
AbstractStinson introduced authentication perpendicular arrays APAλ(t,k,v), as a special kind of perpendicular arrays, to construct authentication and secrecy codes. Ge and Zhu introduced APAV(q,k) to study APA1(2,k,v) for k=5, 7. Chen and Zhu determined the existence of APAV(q,k) with q a prime power ≡3(mod4) and odd k>1. In this article, we show that for any prime power q≡5(mod8) and any k≡1(mod4) there exists an APAV(q,k) whenever q>((E+E2+4F)/2)2, where E=[(7k−23)m+3]25m−3, F=m(2m+1)(k−3)25m and m=(k−1)/4
- …