发表机构
Quantum Optics Jena GmbH; Institute of Applied Physics, Friedrich Schiller University Jena; Max Planck School of Photonics, Friedrich Schiller University Jena; University of Applied Sciences Nordhausen; Fraunhofer Institute for Applied Optics and Precision Engineering IOF（量子光学耶拿有限公司; 耶拿弗里德里希·席勒大学应用物理研究所; 耶拿弗里德里希·席勒大学马克斯·普朗克光子学院; 诺德豪森应用技术大学; 弗劳恩霍夫应用光学和精密工程研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究在德国图林根州部署了140公里光纤的量子安全网络，结合QKD与PQC技术，实现无需修改现有医疗系统的远程医疗安全传输，验证了量子安全关键基础设施的实用框架。
AI 中文摘要
量子计算机对经典公钥密码构成的威胁，推动了医疗、金融、能源等关键基础设施领域量子安全通信的部署。量子密钥分发（QKD）与后量子密码（PQC）提供互补的安全保障：前者具备信息论安全的密钥交换能力，后者具备抗量子攻击的端到端认证能力，二者可在分层架构中结合。本研究在德国图林根州部署了一套量子安全现场网络，通过可信节点架构将农村医疗亭与大学医院连接，所涉光纤链路总长度达140公里，包含地下与架空光纤链路；该网络整合了基于纠缠的QKD与端到端PQC技术。与依赖专用密钥管理系统向应用转发密钥的传统部署不同，本架构将QKD密钥直接注入相邻节点间基于Linux的标准VPN隧道，同时由PQC保障端到端通信安全，完全兼容现有基础设施与软件。研究中生成了810nm与1550nm的偏振纠缠光子对，其中电信波段光子通过部署的光纤传输；主动偏振稳定与色散补偿技术可维持纠缠态，实现了22天的连续全自动运行，进一步凸显了基于纠缠的QKD在真实光纤环境中的技术成熟度。尽管两条部署链路分别在不同时段运行，架空链路的稳定性明显更差，误码率（QBER）变化与风速的相关性最强。生成的密钥无需修改现有医疗系统，即可保障远程医疗概念验证的安全，为量子安全关键基础设施提供了实用框架。
英文摘要
The threat quantum computers pose to classical public-key cryptography motivates the deployment of quantum-safe communication for critical infrastructure such as healthcare, finance, and energy systems. Quantum key distribution (QKD) and post-quantum cryptography (PQC) offer complementary security guarantees, information-theoretic key exchange and quantum-resistant end-to-end authentication that can be combined in a layered architecture. Here, we demonstrate a field-deployed quantum-secure network integrating entanglement-based QKD with end-to-end PQC over 140 km of installed fiber in Thuringia, Germany, connecting a rural health kiosk to a university hospital via a trusted-node architecture comprising heterogeneous underground and aerial fiber links. Unlike conventional deployments that rely on a dedicated key management system to forward keys to applications, our architecture injects QKD keys directly into standard Linux-based VPN tunnels between adjacent nodes, while PQC secures the communication end-to-end, remaining fully compatible with existing infrastructure and software. Polarization-entangled photon pairs were generated at 810 nm and 1550 nm, with the telecom photon transmitted over deployed fiber. Active polarization stabilization and dispersion compensation preserve the entanglement and enable 22 days of continuous, fully autonomous operation, further underscoring the technological maturity of entanglement-based QKD approaches in a real-world fiber environment. Although the two deployed links were operated during separate rather than concurrent periods, the predominantly aerial link exhibited markedly greater instability, with QBER variations most strongly correlated with wind speed. The generated keys secured a telemedicine proof-of-concept without modifying existing medical systems, demonstrating a practical framework for quantum-safe critical infrastructures.
