High-precision Hardware Oscillators Ensemble for GNSS Attack Detection

TL;DR

This paper introduces an onboard ensemble of high-precision oscillators for GNSS receivers to detect sophisticated timing attacks independently of network connectivity, demonstrating high sensitivity and reduced detection latency.

Contribution

It proposes a novel method using embedded reference clock ensembles with chip-scale oscillators for robust GNSS attack detection during network outages.

Findings

Detects GNSS attacks causing 0.3 microsecond time offset

Halves detection latency compared to existing methods

Effective even during prolonged network disconnections

Abstract

A wide gamut of important applications rely on global navigation satellite systems (GNSS) for precise time and positioning. Attackers dictating the GNSS receiver position and time solution are a significant risk, especially due to the inherent vulnerability of GNSS systems. A first line of defense, for a large number of receivers, is to rely on additional information obtained through the rich connectivity of GNSS enabled platforms. Network time can be used for direct validation of the GNSS receiver time; but this depends on network availability. To allow attack detection even when there are prolonged network disconnections, we present a method based on on-board ensemble of reference clocks. This allows the receiver to detect sophisticated attacks affecting the GNSS time solution, independently of the specific attack methodology. Results obtained with Chip-Scale Oven Compensated Oscillators (CS-OCXO) are promising and demonstrate the potential of embedded ensembles of reference clocks, detecting attacks causing modifications of the receiver time offset as low as 0.3us, with half the detection latency compared to related literature.