Modular network for high-rate quantum conferencing

TL;DR

This paper introduces a modular continuous-variable quantum network architecture that enables high-rate, secure conference keys over arbitrary distances by combining measurement-device-independent star modules with a relay-based protocol.

Contribution

It proposes a novel modular design for quantum networks using measurement-device-independent star modules, enhancing security and scalability for quantum conferencing.

Findings

Achieves high-rate quantum conference keys over arbitrary distances.

Utilizes off-the-shelf optical components for practical implementation.

Ensures unconditional security through measurement-device-independent architecture.

Abstract

One of the main open problems in quantum communication is the design of efficient quantum-secured networks. This is a challenging goal, because it requires protocols that guarantee both unconditional security and high communication rates, while increasing the number of users. In this scenario, continuous-variable systems provide an ideal platform where high rates can be achieved by using off-the-shelf optical components. At the same time, the measurement-device independent architecture is also appealing for its feature of removing a substantial portion of practical weaknesses. Driven by these ideas, here we introduce a modular design of continuous-variable network where each individual module is a measurement-device-independent star network. In each module, the users send modulated coherent states to an untrusted relay, creating multipartite secret correlations via a generalized Bell detection. Using one-time pad between different modules, the network users may share a quantum-secure conference key over arbitrary distances at constant rate.