Secret Sharing and Proactive Renewal of Shares in Hierarchical Groups

TL;DR

This paper introduces a hierarchical secret sharing scheme that enhances security against prolonged attacks by incorporating proactive renewal, utilizing Elliptic Curve Cryptography for efficiency.

Contribution

It presents a novel hierarchical secret sharing method with proactive share renewal to resist long-term adversaries, leveraging elliptic curve cryptography for improved performance.

Findings

Enhanced security against long-term share compromise

Efficient computations using elliptic curve cryptography

Hierarchical structure supports complex user organizations

Abstract

Secret sharing in user hierarchy represents a challenging area for research. Although a lot of work has already been done in this direc- tion, this paper presents a novel approach to share a secret among a hierarchy of users while overcoming the limitations of the already exist- ing mechanisms. Our work is based on traditional (k +1; n)-threshold secret sharing, which is secure as long as an adversary can compromise not more than k secret shares. But in real life it is often feasible for an adversary to obtain more than k shares over a long period of time. So, in our work we also present a way to overcome this vulnerability, while implementing our hierarchical secret sharing scheme. The use of Elliptic Curve Cryptography makes the computations easier and faster in our work.