Secret Sharing on Evolving Multi-level Access Structure

Abstract

Secret sharing is a process that allows storing secret information in a distributed manner among several participants. In the original setting of secret sharing schemes, it was assumed that the total number of participants is fixed from the very beginning. However, to meet the state of the art needs, it is required to consider the scenario where any time a new participant can join and the total number of participants is (possibly) unbounded. Evolving secret sharing solves the problem. Secret sharing for evolving threshold access structure has been considered in the last few years. Here, we consider the Multi-level access structures. More specifically, we consider evolving compartmental and hierarchical access structures. We provide constructions with the estimation of share sizes.