Quantum key distribution in a packet-switched network

TL;DR

This paper demonstrates that packet switching can be effectively used in quantum networks for quantum key distribution, achieving practical key rates and enhancing performance through storage strategies, advancing the development of large-scale quantum networks.

Contribution

It introduces a three-step approach for optimizing key rates in packet-switched quantum networks and shows practical feasibility without optical storage, with potential improvements using storage strategies.

Findings

Practical key rates achievable in a 16-user network without optical storage.

Using ultra-low-loss fiber delay lines can improve key rates.

Cut-off storage times significantly enhance network performance.

Abstract

Packet switching revolutionized the Internet by allowing the efficient use of network resources for data transmission. In a previous work, we introduced packet switching in quantum networks as a path to the Quantum Internet and presented a proof-of-concept for its application to quantum key distribution (QKD). In this paper, we outline a three-step approach for key rate optimization in a packet-switched network. Our simulated results show that practical key rates may be achieved in a sixteen-user network with no optical storage capacity. Under certain network conditions, we may improve the key rate by using an ultra-low-loss fiber delay line to store packets during network delays. We also find that implementing cut-off storage times in a strategy analogous to real-time selection in free-space QKD can significantly enhance performance. Our work demonstrates that packet switching is imminently suitable as a platform for QKD, an important step towards developing large-scale and integrated quantum networks.