High key rate quantum conference key agreement with unconditional security

TL;DR

This paper introduces a practical, high-rate quantum conference key agreement protocol for three users, utilizing existing technology components, and capable of secure operation over long distances, advancing quantum network security.

Contribution

The authors propose a new quantum CKA protocol that achieves high key rates with simple, implementable components, suitable for large-scale quantum networks.

Findings

Protocol is secure with information-theoretic guarantees.

Anticipated to operate over 600 km with current technology.

Suitable for large-scale quantum network deployment.

Abstract

Quantum cryptography is a major ingredient of the future quantum internet that promises various secure communication tasks. Quantum conference key agreement (CKA) is an important cryptographic primitive of quantum cryptography, which provides the conference key among multiple users simultaneously. However, quantum CKA is currently far from practical application due to the low conference key rate. Here, we propose a quantum CKA protocol of three users with information-theoretic security. Our protocol only requires phase-randomized weak coherent sources and threshold single-photon detectors, and is anticipated to be experimentally demonstrated over 600 km under current technology. Our scheme can be widely implemented in the approaching large-scale quantum network.