47 research outputs found
Authentication and Secrecy Codes for Equiprobable Source Probability Distributions
We give new combinatorial constructions for codes providing authentication
and secrecy for equiprobable source probability distributions. In particular,
we construct an infinite class of optimal authentication codes which are
multiple-fold secure against spoofing and simultaneously achieve perfect
secrecy. Several further new optimal codes satisfying these properties will
also be constructed and presented in general tables. Almost all of these appear
to be the first authentication codes with these properties.Comment: 5 pages (double-column); to appear in Proc. IEEE International
Symposium on Information Theory (ISIT 2009, Seoul, South Korea
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 an almost-universal hash function family with applications to authentication and secrecy codes
Universal hashing, discovered by Carter and Wegman in 1979, has many
important applications in computer science. MMH, which was shown to be
-universal by Halevi and Krawczyk in 1997, is a well-known universal
hash function family. We introduce a variant of MMH, that we call GRDH,
where we use an arbitrary integer instead of prime and let the keys
satisfy the
conditions (), where are
given positive divisors of . Then via connecting the universal hashing
problem to the number of solutions of restricted linear congruences, we prove
that the family GRDH is an -almost--universal family of
hash functions for some if and only if is odd and
. Furthermore, if these conditions are
satisfied then GRDH is -almost--universal, where is
the smallest prime divisor of . Finally, as an application of our results,
we propose an authentication code with secrecy scheme which strongly
generalizes the scheme studied by Alomair et al. [{\it J. Math. Cryptol.} {\bf
4} (2010), 121--148], and [{\it J.UCS} {\bf 15} (2009), 2937--2956].Comment: International Journal of Foundations of Computer Science, to appea
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
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
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