# A trusted-node-free eight-user metropolitan quantum communication network

## TL;DR

This paper presents a scalable, trusted-node-free quantum communication network connecting 8 users in a city, enabling secure, simultaneous pairwise connections with minimal infrastructure and hardware.

## Contribution

It introduces a novel fully connected quantum network topology that operates without trusted nodes and is scalable to many users.

## Key findings

- Secure connections established between all user pairs
- Network topology is scalable and minimizes infrastructure
- Supports traffic management features

## Abstract

Quantum communication is rapidly gaining popularity due to its high security and technological maturity. However, most implementations are limited to just two communicating parties (users). Quantum communication networks aim to connect a multitude of users. Here we present a fully connected quantum communication network on a city wide scale without active switching or trusted nodes. We demonstrate simultaneous and secure connections between all 28 pairings of 8 users. Our novel network topology is easily scalable to many users, allows traffic management features and minimises the infrastructure as well as the user hardware needed.