How is OSNMA data generated and broadcasted by Galileo?

OSNMA data, in the current system implementation, is generated on ground. The European GNSS Service Centre (GSC), part of the European GNSS infrastructure, plays a central role in the provision of the Galileo OSNMA as it hosts the OSNMA module in charge of generating the necessary elements to perform the authentication of the Navigation Messages. The OSNMA data generated on ground is uplinked to the Galileo space segment for broadcasting. No retrofitting is needed on the Galileo satellites currently deployed in orbit for the provision of the OSNMA service.