Multi-secret Sharing Scheme Using Modular Inverse for Compartmented Access Structure

Abstract

Secret sharing scheme is a cryptographic primitive or a method for increasing the security of crucial information or data. It is used to share a secret among a set of participants, such that specific sets of participants can uniquely reconstruct the secret by pooling their shares. In this paper, we have proposed a new multi-secret sharing scheme for compartment access structure. In this access structure, the set of participants is partitioned into different compartments. The secret can be obtained only if the threshold number of participants from each of the compartments reconstruct their compartment secret, and participate in recovering the actual secret. The proposed scheme uses Shamir’s scheme first to retrieve partial secrets and combines them to form the requested secret. The scheme can also verify whether the retrieved secret is valid or not. Security analysis of the scheme is carried out and showed that the scheme resists both the insider as well as outsider attacks. Our proposed scheme is simple and easy to understand as we have used only the modular inverse concept.