Detecting GNSS misbehaviour with high-precision clocks

Abstract

To mitigate spoofing attacks targeting global navigation satellite systems (GNSS) receivers, one promising method is to rely on alternative time sources, such as network-based synchronization, in order to detect clock offset discrepancies caused by GNSS attacks. However, in case of no network connectivity, such validation references would not be available. A viable option is to rely on a local time reference; in particular, precision hardware clock ensembles of chip-scale thermally stable oscillators with extended holdover capabilities. We present a preliminary design and results towards a custom device capable of providing a stable reference, with smaller footprint and cost compared to traditional precision clocks. The system is fully compatible with existing receiver architecture, making this solution feasible for most industrial scenarios. Further integration with network-based synchronization can provide a complete time assurance system, with high short-and long-term stability. CCS CONCEPTS• Security and privacy → Mobile and wireless security; • Networks → Location based services.

High-precision Hardware Oscillators Ensemble for GNSS Attack Detection

“…Adversaryinduced degradation of the time solution, manifesting itself as variations in the GNSS time rate and skewing, can be captured by taking advantage of on-board oscillators [13][14][15]. Intuitively, the progression of the GNSS receiver time should match the one provided by the local oscillator, if it is sufficiently stable during the period of observation [16,17]. Chipscale atomic clocks (CSAC) can address this by providing a long-term stable time reference, outperforming most solutions based on traditional oscillators.…”