Unbreakable distributed storage with quantum key distribution network and password-authenticated secret sharing

TL;DR

This paper presents a secure distributed storage system combining password-authenticated secret sharing with quantum key distribution to ensure information-theoretic security over long-distance networks.

Contribution

It introduces a novel distributed storage approach that integrates quantum key distribution with password-authenticated secret sharing for enhanced security.

Findings

Successfully demonstrated in Tokyo metropolitan area

Achieved information-theoretic security for data transmission

Enhanced robustness of distributed storage systems

Abstract

Distributed storage plays an essential role in realizing robust and secure data storage in a network over long periods of time. A distributed storage system consists of a data owner machine, multiple storage servers and channels to link them. In such a system, secret sharing scheme is widely adopted, in which secret data are split into multiple pieces and stored in each server. To reconstruct them, the data owner should gather plural pieces. Shamir's (k, n)-threshold scheme, in which the data are split into n pieces (shares) for storage and at least k pieces of them must be gathered for reconstruction, furnishes information theoretic security, that is, even if attackers could collect shares of less than the threshold k, they cannot get any information about the data, even with unlimited computing power. Behind this scenario, however, assumed is that data transmission and authentication must be perfectly secure, which is not trivial in practice. Here we propose a totally information theoretically secure distributed storage system based on a user-friendly single-password-authenticated secret sharing scheme and secure transmission using quantum key distribution, and demonstrate it in the Tokyo metropolitan area.