Scalable authentication and optimal flooding in a quantum network

• Main Authors: Solomons, Naomi R, Fletcher, Alasdair I, Aktas, Djeylan, Venkatachalam, Natarajan, Wengerowsky, Sören, Lončarić, Martin, Neumann, Sebastian P, Liu, Bo, Samec, Željko, Stipčević, Mario, Ursin, Rupert, Pirandola, Stefano, Rarity, John G, Joshi, Siddarth Koduru
• Format: Journal Article
• Language: English
• Published: 21-06-2023
• Subjects: Physics - Quantum Physics
• DOI: 10.48550/arxiv.2101.12225

PRX Quantum 3, 020311 (2022) 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.