Galileo vs. spoofing: ESA tests in real-world environments

Written by Copernical Team Tuesday, 24 February 2026 09:24

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From adding timestamps to banking transactions to mapping the best route to a destination, satellite navigation plays a significant role in daily life. At the same time, attempts to interfere with and fake navigation signals are increasing. For the last seven months, a new verification service for Galileo has mitigated the threat of spoofing in the Open Service by confirming that the satellite navigation data used for positioning originated in the Galileo system.

The Open Service Navigation Message Authentication (OSNMA) mitigates the threat of spoofing by adding an authenticity stamp to the real signal from the satellite. The stamp acts as a digital signature that ensures the satellite navigation data obtained by a receiver are coming from the Galileo system. This is critical for applications where safety and trustworthiness are a priority, such as transport.

With close to 100% coverage around the world, OSNMA has a similar availability as Galileo’s Open Service. The authentication service is available to most receivers and can serve many applications, from consumer to professional, as all are susceptible to spoofing.

OSNMA is provided to users free of charge. Receivers that already process the navigation message from the Galileo Open Service can be upgraded to interpret the OSNMA information which is now embedded in the message. For many receivers, the upgrades for OSNMA processing only require software changes.

OSNMA Initial Service was declared by the European Commission (EC) on 24 July 2025 and the Service Definition Document was published by the EU Space Programme Agency (EUSPA) the same day.

Since OSNMA was declared operational in July, the European Space Agency (ESA) has been continuously monitoring it with the Galileo Second Generation System Testbed. Thanks to a worldwide network of experimental sensor stations, the testbed has real-time access to OSNMA broadcasted by the Galileo satellites.

The testbed operations team can continuously verify the authentication of every Galileo satellite and confirm the correctness of the cryptographic material publicly broadcast by the satellites. Since the service declaration of OSNMA, this newcomer to the Galileo family has benefitted most of the navigation user communities in line with expectations.