Abstract The notion of Generalized Oblivious Transfer (GOT) was introduced by Ishai and
Kushilevitz (Proceeding of ISTCS97, IEEE Computer Society, pp 174–184, 1997). In a GOT …

These are basically the lecture notes for the short course" Applications of Combinatorics to
Information-Theoretic Cryptography", Central European University, Budapest, May-June …

A secret sharing scheme is non-perfect if some subsets of players that cannot recover the
secret value have partial information about it. The information ratio of a secret sharing …

We present a new improvement in the linear programming technique to derive lower bounds
on the information ratio of secret sharing schemes. We obtain non-Shannon-type bounds …

We present new families of access structures that, similarly to the multilevel and
compartmented access structures introduced in previous works, are natural generalizations …

Beimel and Orlov proved that all information inequalities on four or five variables, together
with all information inequalities on more than five variables that are known to date, provide …

We present a new improvement in the linear programming technique to derive lower bounds
on the information ratio of secret sharing schemes. We obtain non-Shannon-type bounds …

We study the problem of finding the worst-case bound for the size of the result $ Q (\mathbb
{D}) $ of a fixed conjunctive query $ Q $ applied to a database $\mathbb {D} $ satisfying …

Optimizing the maximum, or average, length of the shares in relation to the length of the
secret for every given access structure is a difficult and long-standing open problem in …

The efficiency of a secret sharing scheme is measured via its information ratio. The optimal
information ratio (OIR) of an access structure is the infimum of the information ratios of all …