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The resolutions of the designs in two infinite series of 4-designs constructed by Alltop and Hubaut are the subject of this study. We examine two types of resolutions, namely the s -resolutions and the point-missing s -resolutions. The result can essentially be stated that the designs possess 3-resolutions and point-missing s -resolutions for s = 2 , 3 subject to a necessary numerical condition of the parameters. [ABSTRACT FROM AUTHOR]

The aim of the paper is to present a general construction of strongly aperiodic logarithmic signatures (SALS) for elementary abelian p-groups.Their existence significantly extends the classes of tame logarithmic signatures which are used for the cryptosystem MST 3 {\mathrm{MST}_{3}}.They have particular characteristics that do not share with the well-known classes of transversal or fused transversal logarithmic signatures, and therefore they will play a vital role for logarithmic signature based cryptosystems in practice.In theory, the construction of SALS is interesting in its own right as well. [ABSTRACT FROM AUTHOR]

The aim of the paper is to present a general construction of strongly aperiodic logarithmic signatures (SALS) for elementary abelian p-groups. Their existence significantly extends the classes of tame logarithmic signatures which are used for the cryptosystem MST3. They have particular characteristics that do not share with the well-known classes of transversal or fused transversal logarithmic signatures, and therefore they will play a vital role for logarithmic signature based cryptosystems in practice. In theory, the construction of SALS is interesting in its own right as well. [ABSTRACT FROM AUTHOR]

Logarithmic signatures for finite groups are the essential constituent of public key cryptosystems and . Especially they form the main component of the private key of . Regarding the use of , it has become a vital issue to construct new classes of logarithmic signatures having features that do not share with the well-known class of transversal or fused transversal logarithmic signatures. For this purpose Baumeister and de Wiljes recently presented an interesting method of constructing aperiodic logarithmic signatures for abelian groups. In this paper we introduce the concept of strongly aperiodic logarithmic signatures and show their constructions for abelian p-groups on the basis of the Baumeister-de Wiljes method. [ABSTRACT FROM AUTHOR]

Abstract: This paper aims to present new upper bounds on the size of separating hash families. These bounds improve previously known bounds for separating hash families. [ABSTRACT FROM AUTHOR]

A new type of public key cryptosystem, called MST3, has been recently introduced on the basis of covers and logarithmic signatures for non-abelian finite groups. The class of Suzuki 2-groups has been proposed for a possible realization of the generic scheme. Due to their simple structure, the groups enable us to study the security of the system and also provide an efficient implementation. An earlier relevant result of the cryptanalysis has shown that the transversal logarithmic signatures are unfit for use in this realization. In this paper we present a revised version of MST3 for the Suzuki 2-groups and show a thorough study of its security. Using heuristic and algebraic methods we establish strong lower bounds for the workload of conceivable direct attacks on the private key of the scheme. We then develop a powerful chosen plaintext attack which allows us to rule out the usage of a certain class of logarithmic signatures. In addition, we show a class of logarithmic signatures withstanding this attack and thus to our knowledge they could be used in the realization of the scheme. Finally, we describe and discuss the implementation issues of the scheme in detail and include data of its performance obtained from an experimental result. [ABSTRACT FROM AUTHOR]

Simple nontrivial s -resolvable t -designs for t ≥ 3 and 1 < s < t are still very sparsely investigated up to now. The problem has been tackled in a recent paper by the author. Here, we continue to explore the problem by focussing on the case t = 3 and s = 2. In 1963 Shrikhande and Raghavarao published a recursive construction for BIBD. Different authors have studied generalizations of the method for constructing simple 3-designs. In this paper we show that the method can be further extended to studying simple 3-designs having 2-resolutions. As a result, we are able to construct many new infinite families of simple 2-resolvable 3-designs. [ABSTRACT FROM AUTHOR]

Abstract: Shrikhande and Raghavarao (1963) published a recursive construction for designs that starts with a resolvable design (the “master design”) and then uses a second design (“the indexing design”) to take certain unions of blocks in each parallel class of the master design. Several variations of this construction have been studied by different authors. We revisit this construction, concentrating on the case where the master design is a resolvable BIBD and the indexing design is a 3-design. We show that this construction yields a 3-design under certain circumstances. The resulting 3-designs have block size and they are resolvable. We also construct some previously unknown simple designs by this method. [Copyright &y& Elsevier]

For communication schemes employing Frequency Hopping/Multiple Frequency Shift Keying modulation, we present an algorithm for finding good non-binary synchronization sequences, which are permutations, to be used with permutation codes to synchronize/resynchronize data in channels with background noise and interference(frequency jamming/fading). For the synchronization sequences, new analytical expressions for the probability of false acquisition are also given. Using simulation results, we show that our synchronization sequences perform better than some conventional non-binary synchronization sequences, in the presence of background noise and interference. [ABSTRACT FROM AUTHOR]