Time Synchronization for TESLA-based GNSS-enabled Systems
Jason Anderson, SHERMAN C. LO, Todd Walter · Proceedings of the Satellite Division's International Technical Meeting (Online)/Proceedings of the Satellite Division's International Technical Meeting (CD-ROM) · 2022
Timed Efficient Stream Loss-tolerant Authentication (“TESLA”) is well-posed to serve as the primary cryptographic authentication algorithm for GNSS. TESLA provides excellent features, such as loss-tolerance and bandwidth efficiency, while also explicitly incorporating the need for time synchronization. This work discusses how to certify and re-synchronize the onboard clock to loosely time-synchronization requirements in the context of GNSS. Our certification and re-synchronization procedure is secure against a man-in-the-middle delaying adversary. By secure, we prevent forgeries from being accepted, but denial of service is still possible. Moreover, we discuss security considerations of the onboard clock regarding the disclosure of the onboard clock time.