Secure Two-Way Fiber-Optic Time Transfer Against Sub-ns Asymmetric Delay Attack With Clock Model-Based Detection and Mitigation Scheme

作者：Yang Li, Jinlong Hu, Yan Pan, Wei Huang, Li Ma, Jie Yang, Shuai Zhang, Yujie Luo, Chuang Zhou, Chenlin Zhang, Heng Wang, Yun Shao, Yichen Zhang, Xing Chen, Ziyang Chen, Song Yu, Hong Guo, Bingjie Xu · 发表于：IEEE Transactions on Instrumentation and Measurement · 年份：2023 · DOI：10.1109/tim.2023.3268476 · 被引用次数：14 · 研究领域：Advanced Frequency and Time Standards、Quantum optics and atomic interactions、Network Time Synchronization Technologies

Two-way fiber-optic time transfer (TWFTT) is a promising precise time synchronization technique with subnanosecond stability. However, the asymmetric delay attack is a severe threat, which can deteriorate the performance of the TWFTT system. In this article, a clock model-based scheme is used to defend the subnanosecond asymmetric delay attack. For the scheme, a security threshold is set according to a two-state clock model, and the estimated frequency difference is excluded from the measured time difference to detect the subnanosecond asymmetric delay attack. Systematic detection and mitigation scheme for asymmetric delay attack is developed in this article. Theoretical simulation and experimental demonstration are implemented to explore the feasibility of the method. A TWFTT system of time stability with 24.5, 3.98, and 2.95 ps at average times of 1, 10, and 100 s is shown under subnanosecond asymmetric time delay attack experimentally for the first time. The proposed method provides a promising secure subnanosecond precise time synchronization technique against asymmetric delay attacks.