# GNSS Signal Authentication via Power and Distortion Monitoring

## TL;DR

This paper introduces a low-cost, firmware-updatable Power-Distortion detector for GNSS receivers that reliably detects spoofing and jamming by analyzing received power and signal distortion, distinguishing malicious interference from normal multipath effects.

## Contribution

The paper presents a novel, hardware-independent detection technique that can be implemented via firmware update, effectively identifying low-power spoofing and jamming in GNSS signals.

## Key findings

- Correctly detected all spoofing and jamming attacks in tests
- Maintained false alarm rate below 0.6%
- Validated on over 900,000 detection tests

## Abstract

We propose a simple low-cost technique that enables civil Global Positioning System (GPS) receivers and other civil global navigation satellite system (GNSS) receivers to reliably detect carry-off spoofing and jamming. The technique, which we call the Power-Distortion detector, classifies received signals as interference-free, multipath-afflicted, spoofed, or jammed according to observations of received power and correlation function distortion. It does not depend on external hardware or a network connection and can be readily implemented on many receivers via a firmware update. Crucially, the detector can with high probability distinguish low-power spoofing from ordinary multipath. In testing against over 25 high-quality empirical data sets yielding over 900,000 separate detection tests, the detector correctly alarms on all malicious spoofing or jamming attacks while maintaining a <0.6% single-channel false alarm rate.