Range Authentication of Galileo E1 / E5 Signals Using Different Assisted Methods on a GNSS Hardware Receiver

Benedikt Schreiber, Fabio Garzia, Rocío Parra, Himanshu Gupta, Matthias Overbeck, Alexander Rügamer, Jan Ackermann, Mark Holbrow

Abstract:	This paper presents a flexible multi-band range-authentication mechanism implemented in a Galileo GNSS hardware receiver, analysing a potential extension of the existing Assisted Commercial Authentication Service (ACAS) scheme to also incorporate E1 and E5 authentication signals. By capturing regular snapshots of incoming signals and correlating them with partially encrypted PRN code snippets, the receiver verifies the authenticity of observed pseudoranges against reference values derived from real-time navigation solutions. Experimental validation under realistic spoofing conditions demonstrates that E1-only authentication offers rapid detection (2 s in hot starts) but requires a broader authentication threshold. In contrast, E5-only authentication achieves superior accuracy at thresholds as low as 12 m, with timing similar to E6-based methods (3 s in hot start). A combined approach that cross-checks pseudoranges between bands delivers near-E5 performance while maintaining robust protection against spoofing. These findings highlight the promise of multi-band authentication as a powerful tool for enhancing receiver resilience against interference and spoofing.
Published in:	Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025) September 8 - 12, 2025 Hilton Baltimore Inner Harbor Baltimore, Maryland
Pages:	1 - 9
Cite this article:	Schreiber, Benedikt, Garzia, Fabio, Parra, Rocío, Gupta, Himanshu, Overbeck, Matthias, Rügamer, Alexander, Ackermann, Jan, Holbrow, Mark, "Range Authentication of Galileo E1 / E5 Signals Using Different Assisted Methods on a GNSS Hardware Receiver," Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025), Baltimore, Maryland, September 2025, pp. 1-9. https://doi.org/10.33012/2025.20222
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