New Secret Sharing Schemes from Old

A secret sharing scheme protects a secret (key) by distributing related information among a group of participants. This is done in such a way that only certain pre-specified groups of these participants (the access structure) can reconstruct the secret. In this paper, we introduce a new measure of the efficiency of a perfect secret sharing scheme and examine methods of producing new secret sharing schemes from existing ones. These constructions can be used to help determine the optimal information rates for certain access structures.