Which GNSS counterfeit attack detection technique uses joint sensor data?

• A. Cryptographic validation of GNSS signals only
• B. Cross-validation with inertial navigation system, stellar sensors, or other GNSS signals
• C. Visual inspection of satellite IDs
• D. Sole reliance on GNSS C/N0 thresholds

Answer: (B)

Detecting GNSS counterfeit attacks often relies on combining information from multiple, independent sensors to spot inconsistencies that a counterfeit signal cannot plausibly reproduce. Cross-checking GNSS data with an inertial navigation system provides an independent motion estimate from accelerometers and gyros, which will drift differently from GNSS but should remain internally consistent with real movement. Star/stellar sensors give an absolute reference for attitude or position that is not tied to satellite signals, so any mismatch with GNSS readings signals a potential spoof. Checking against other GNSS signals or constellations adds another independent data stream, making it harder for a counterfeit to spoof all systems in the same way.

Because this approach leverages joint data from disparate sources, it exposes discrepancies that a spoofed GNSS signal alone might conceal. In contrast, relying solely on cryptographic validation, heightening GNSS signal strength thresholds, or visually inspecting satellite IDs either focuses on a single signal property or is not robust in real-time, making them less effective for detecting counterfeit attacks.