A construction for multisecret threshold schemes

Abstract

A multisecret threshold scheme is a system that protects a number of secrets (or keys) among a group of participants, as follows. Given a set of n participants, there is a secret sK associated with each k-subset K of these participants. The scheme ensures that sK can be reconstructed by any group of t participants in K (1 ≤ t ≤ k). A lower bound has been established on the amount of information that participants must hold in order to ensure that any set of up to w participants (0 ≤ w ≤ n - k + t - 1) cannot obtain any information about a secret with which they are not associated. In this paper, for parameters t = 2 and w = n - k + t - 1, we give a construction for multisecret threshold schemes that satisfy this bound. © 1996 Kluwer Academic Publishers.