Authentication of GPS Modernized Signals Using TESLA Chimera

Michael H. Cole, James T. Gillis, Rachel I. Allen, and Albert H. Hayden

Abstract:	Spoofing of Global Navigation Satellite System (GNSS) signals continues to grow as a threat to position, navigation, and timing (PNT) users globally, including safety-of-life and other critical infrastructure users. United States (U.S.) Presidential Space Policy Directive 7 includes direction for the U.S. government to pursue authentication solutions for Global Positioning System (GPS) PNT services. We propose a Timed Efficient Stream Loss-tolerant Authentication (TESLA) Chips-Message Robust Authentication (Chimera) based authentication approach for modernized GPS signals that would provide in-band authentication of ranging measurements and navigation message content. Specific modernized civil navigation messages formats and message broadcast schedules are proposed, with associated trade-offs for frequency of authentication events vs. bandwidth consumed. We also present the results of simulations characterizing performance metrics including timeliness of authentication events for a representative notional configuration.
Published in:	Proceedings of the 2025 International Technical Meeting of The Institute of Navigation January 27 - 30, 2025 Hyatt Regency Long Beach Long Beach, California
Pages:	479 - 493
Cite this article:	Cole, Michael H., Gillis, James T., Allen, Rachel I., Hayden, Albert H., "Authentication of GPS Modernized Signals Using TESLA Chimera," Proceedings of the 2025 International Technical Meeting of The Institute of Navigation, Long Beach, California, January 2025, pp. 479-493. https://doi.org/10.33012/2025.20013
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