Blocking sets and semifields

Semifields, Relative Difference Sets, and Bent Functions

Recently, the interest in semifields has increased due to the discovery of several new families and progress in the classification problem. Commutative semifields play an important role since they are equivalent to certain planar functions (in the case of odd characteristic) and to modified planar functions in even characteristic. Similarly, commutative semifields are equivalent to relative dif...

Blocking and Double Blocking Sets in Finite Planes

In this paper, by using properties of Baer subplanes, we describe the construction of a minimal blocking set in the Hall plane of order q2 of size q2 + 2q + 2 admitting ∗This author has been supported as a postdoctoral fellow of the Research Foundation Flanders (Belgium) (FWO). †This author was supported by a Visiting Professor grant of the Special Research Fund Ghent University (BOF project nu...

Blocking sets in handcuffed designs

In this paper we determine the spectrum of possible cardinalities of a blocking set in a H(v,3,A) and in a H(v,4,1). Moreover we construct, for each admissible ~9, a H(v,3,1) without blocking sets. Introduction A handcuffed design with parameters v, k, A, or for short an H(v,k,A), consists of a set of ordered k-subsets of a v-set, called handcuffed blocks. In a block (a., a z ' ... ,a!:) each e...

Blocking sets in chain geometries

Finite semifields

This note surveys the known finite semifields and discusses the question: How many finite semifields of a given order are there up to isotopism?