由量子密钥分发网络保障安全的精密授时设施之间的国际时间传递
International time transfer between precise timing facilities secured with a quantum key distribution network
AI总结：
本文演示利用卫星 QKD 与地面“最后一英里”QKD 链路，安全连接相距逾 900 公里的两座 PTF，并验证未来 QKD 卫星可依托现有 OGS 实现国际加密时间传递。
摘要：
全球导航卫星系统（GNSS），例如 GPS 和 Galileo，在全球范围内提供精密时间与空间坐标，并构成现代社会关键基础设施的一部分。为可靠运行 GNSS，需要高度准确且稳定的系统时间，例如由世界各地精密授时设施（PTF）中的多个独立时钟所提供的时间。PTF 之间的相对时钟偏差会被周期性测量，以便拥有一个用于同步 GNSS 卫星时钟的备用系统。PTF 之间通信的安全性和完整性至关重要：一旦遭到破坏，可能导致 GNSS 服务中断。因此，这是通过量子密钥分发（QKD）进行保护的一个极具吸引力的用例，因为该技术可提供信息论安全性。我们通过在两个 PTF 之间共享加密的时间同步信息，完成了此类用例的现场试验演示；其中一个 PTF 位于德国 Oberpfaffenhofen，另一个位于意大利 Matera，两地直线距离超过 900 公里。为跨越这一长距离，需要一套卫星 QKD 系统，并辅以“最后一英里”地面链路，将光学地面站（OGS）连接到 PTF 的实际位置。在我们的演示中，我们部署了两套完整的 QKD 系统，以保护两个地点的最后一英里连接，并通过仿真表明，未来的 QKD 卫星将能够利用现有 OGS，在 Oberpfaffenhofen 与 Matera 之间分发密钥。
英文摘要：
Global Navigation Satellite Systems (GNSSs), such as GPS and Galileo, provide precise time and space coordinates globally and constitute part of the critical infrastructure of modern society. To reliably operate GNSS, a highly accurate and stable system time is required, such as the one provided by several independent clocks hosted in Precise Timing Facilities (PTFs) around the world. Periodically, the relative clock offset between PTFs is measured to have a fallback system to synchronize the GNSS satellite clocks. The security and integrity of the communication between PTFs is of paramount importance: if compromised, it could lead to disruptions to the GNSS service. Therefore, it is a compelling use-case for protection via Quantum Key Distribution (QKD), since this technology provides information-theoretic security. We have performed a field trial demonstration of such use-case by sharing encrypted time synchronization information between two PTFs, one located in Oberpfaffenhofen (Germany) and one in Matera (Italy) - more than 900km apart as the crow flies. To bridge this large distance, a satellite-QKD system is required, plus a "last-mile" terrestrial link to connect the optical ground station (OGS) to the actual location of the PTF. In our demonstration we have deployed two full QKD systems to protect the last-mile connection at both the locations and have shown via simulation that upcoming QKD satellites will be able to distribute keys between Oberpfaffenhofen and Matera exploiting already existing OGSs.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
