The European Union Agency for the Space Programme (EUSPA) opened the Galileo Open Service Navigation Message Authentication (OSNMA) Public Observation test phase for the secured signal.

The OSNMA is a freely accessible data-authentication function for the Galileo Open Service worldwide. OSNMA provides receivers a first-level of protection against spoofing the Galileo Open Service, assuming that the receiver meets requirements. This is realized by transmitting authentication-specific data in previously reserved fields of the E1 I/NAV message.

Galileo OSNMA improves confidence on the user side by enabling the user to verify the authenticity of the Galileo navigation parameters required for positioning, navigation and timing. In particular, it will allow the user to authenticate geolocation information of the Open Service:

• the ephemerides and clock corrections
• the ionospheric corrections
• the status flags
• the Broadcast Group Delay
• the GST to UTC parameters

https://www.gsc-europa.eu/support-to-developers/osnma-public-observation-test-phase