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Detecting GNSS Spoofing in a Hostile Environment | Erillisverkot & Net Insight at ITSF 2025
Presented by Simo Hallikainen, Erillisverkot and Hans Sjöstrand, Net Insight at ITSF 2025 in Prague on October 29 2025.
When critical infrastructure relies on GNSS as time source, the threat of GNSS spoofing is a challenge that has increased in recent time. Spoofing attacks can originate from bordering areas or even within national boundaries and pose significant threats, particularly to defence and other mission-critical networks.
Unlike jamming, which disrupts signals entirely, spoofing is more insidious and can mislead systems into accepting incorrect timing data and degrade network performance or disabling services altogether. During Jammertest in Norway, Erillisverkot and Net Insight have focused on the impact of GNSS spoofing on time synchronization and how it can be mitigated.
This session shares lessons learned from the field, highlighting how spoofing can be identified through synchronization anomalies and incorporated into performance monitoring. It also explores how critical networks can build greater resilience by integrating spoofing detection capabilities and alternative time sources into the synchronization strategy.
