# Quantum Network: Security Assessment and Key Management

## TL;DR

This paper analyzes security and key management in complex quantum networks, proposing schemes to optimize security levels and data utility, applicable to current and future quantum network implementations.

## Contribution

It introduces novel communication and key management schemes that enhance security and efficiency in large-scale quantum networks.

## Key findings

- Designed a high-security communication scheme with minimal trusted nodes
- Developed key management strategies optimizing data transmission utility
- Results applicable to current quantum networks and future standards

## Abstract

As an extension of quantum key distribution, secure communication among multiple users is an essential task in a quantum network. When the quantum network structure becomes complicated with a large number of users, it is important to investigate network issues, including security, key management, latency, reliability, scalability, and cost. In this work, we utilize the classical and graph theories to address two critical issues in a quantum network: security and key management. First, we design a communication scheme with the highest security level that trusts a minimum number of intermediate nodes. Second, when the quantum key is a limited resource, we design key management and data scheduling schemes to optimize the utility of data transmission. Our results can be directly applied to the current metropolitan and free-space quantum network implementations and potentially be a standard approach for future quantum network designs.