A Construction for Multisecret Threshold Schemes

AbstractA 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 $$(0 \leqslant w \leqslant n - k + t - 1)$$ 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.