Unconditionally secure digital signatures implemented in an 8-user quantum network

TL;DR

This paper demonstrates the first experimental implementation of an unconditionally secure digital signature protocol on a fully connected 8-user quantum network, showing its practical feasibility and security features.

Contribution

It introduces a novel USS protocol implemented on a trusted-node-free quantum network, utilizing bipartite entanglement for secure message authentication.

Findings

Protocol is secure against forgery and repudiation

Successfully demonstrated on a real 8-user quantum network

Performance evaluated with different message lengths

Abstract

The ability to know and verifiably demonstrate the origins of messages can often be as important as encrypting the message itself. Here we present an experimental demonstration of an unconditionally secure digital signature (USS) protocol implemented for the first time, to the best of our knowledge, on a fully connected quantum network without trusted nodes. Our USS protocol is secure against forging, repudiation and messages are transferrable. We show the feasibility of unconditionally secure signatures using only bi-partite entangled states distributed throughout the network and experimentally evaluate the performance of the protocol in real world scenarios with varying message lengths.