A combined symmetric difference and power monitoring GNSS anti-spoofing technique.

Civil Global Navigation Satellite System (GNSS) signals are vulnerable to spoofing attacks that deceive a victim receiver into reporting counterfeit position or time information. The primary contribution of this paper is a non-cryptographic GNSS anti-spoofing technique that "sandwiches" a spoofer between a correlation function distortion monitor and a total in-band power monitor. The defense exploits the difficulty of mounting an effective spoofing attack that simultaneously maintains a low-enough counterfeit signal power to avoid power monitoring alarms while minimizing distortions of the received cross-correlation profile that are indicative of a spoofing attack. Results presented in this paper demonstrate the defense's effectiveness against a sophisticated spoofing attack.