High-rate quantum digital signatures network with integrated silicon photonics

TL;DR

This paper demonstrates a scalable, chip-based quantum digital signature network that significantly improves signature rates and distance, enabling practical secure communications with integrated silicon photonics.

Contribution

It introduces a fully integrated chip-based QDS network with a novel protocol, achieving high signature rates over long distances, advancing practical quantum secure communication.

Findings

Achieved a maximum signature rate of 0.0414 per second for 1 Mbit files.

Demonstrated secure QDS over fiber distances up to 200 km.

Validated the feasibility of integrated silicon photonics for large-scale quantum networks.

Abstract

The development of quantum networks is paramount towards practical and secure communications. Quantum digital signatures (QDS) offer an information-theoretically secure solution for ensuring data integrity, authenticity, and non-repudiation, rapidly growing from proof-of-concept to robust demonstrations. However, previous QDS systems relied on expensive and bulky optical equipment, limiting large-scale deployment and reconfigurable networking construction. Here, we introduce and verify a chip-based QDS network, placing the complicated and expensive measurement devices in the central relay while each user needs only a low-cost transmitter. We demonstrate the network with a three-node setup using an integrated encoder chip and decoder chip. By developing a 1-decoy-state one-time universal hash-QDS protocol, we achieve a maximum signature rate of 0.0414 times per second for a 1 Mbit file over fiber distances up to 200 km, surpassing all current state-of-the-art QDS experiments. This study validates the feasibility of chip-based QDS, paving the way for large-scale deployment and integration with existing fiber infrastructure.