Abstract
Quantum key distribution(QKD)is a physical layer encryption technique that enables two distant parties to exchange secure keys with information-theoretic security.In the last two decades,QKD has transitioned from laboratory research to real-world ap-plications,including multi-user quantum access networks(QANs).This network structure allows users to share a single-photon detector at a network node through time-division multiplexing,thereby significantly reducing the network cost.However,cur-rent QAN implementations require additional hardware for auxiliary tasks such as time synchronization.To address this issue,we propose a cost-efficient QAN that uses qubit-based synchronization.In this approach,the transmitted qubits facilitate time synchronization,eliminating the need for additional synchronization hardware.We tested our scheme by implementing a net-work for two users and successfully achieved average secure key rates of 53.84 kbps and 71.90 kbps for each user over a 50-km commercial fiber spool.In addition,we investigated the capacity of the access network under cross-talk and loss conditions.The simulation results demonstrate that this scheme can support a QAN with 64 users with key rates up to 1070 bps.Our work provides a feasible and cost-effective way to implement a multi-user QKD network,further promoting the widespread application of QKD.
基金项目
国家自然科学基金(62171144)
国家自然科学基金(11905065)
Guangxi Science Foundation(2021GXNSFAA220011)
Guangxi Science Foundation(2021AC19384)
Open Fund of Institute of Pervasive Computing(IPOC)(Beijing University of Posts and Telecommunications)(IPOC2021A02)
Innovation Project of Guangxi Graduate Education(YCSW2022040)
维普
万方数据