Speaker: Arkadii Slinko
Affiliation: The University of Auckland
Title: Secret sharing schemes 2 (elementary introduction)
Date: Tuesday, 21 May 2013
Time: 4:00 pm
Location: Room 6115, Owen Glenn Building

This is a continuation of my talk on 7 May 2013.

This time I will first introduce two large classes of ideal access structures, namely, conjunctive and disjunctive hierarchical access structures. They are characterised by the fact that users are divided into classes so that users within each class are equivalent but users belonging to different classes have different status with respect to the activity. For example, the UN Security Council with its permanent and non-permanent members is a conjunctive hierarchical access structure (to the passage of a resolution).

The main part of the talk will be focused on the connection between ideal secret sharing schemes and matroids. The theorem of Brickel and Davenport (1991) which describes this connection plays a central role in the theory of secret sharing. A short introduction to matroids will be given, no prior knowledge of matroids will be necessary.