Scalable authentication and optimal flooding in a quantum network

TL;DR

This paper presents scalable authentication and flooding protocols for quantum networks, demonstrated on an 8-user test-bed, enhancing security and efficiency in quantum communication systems.

Contribution

It introduces novel protocols for authentication transfer and trust-based flooding, addressing key scalability and security challenges in quantum networks.

Findings

Successful experimental demonstration on an 8-user quantum network

Authentication transfer protocol enables secure key distribution via trusted intermediaries

Flooding protocol improves communication speed and security against malicious nodes

Abstract

The global interest in quantum networks stems from the security guaranteed by the laws of physics. Deploying quantum networks means facing the challenges of scaling up the physical hardware and, more importantly, of scaling up all other network layers and optimally utilising network resources. Here we consider two related protocols, their experimental demonstrations on an 8-user quantum network test-bed, and discuss their usefulness with the aid of example use cases. First, an authentication transfer protocol to manage a fundamental limitation of quantum communication -- the need for a pre-shared key between every pair of users linked together on the quantum network. By temporarily trusting some intermediary nodes for a short period of time (<35 min in our network), we can generate and distribute these initial authentication keys with a very high level of security. Second, when end users quantify their trust in intermediary nodes, our flooding protocol can be used to improve both end-to-end communication speeds and increase security against malicious nodes.