Hacker News Reader

Link for reference: https://www.gsc-europa.eu/galileo/services/galileo-open-serv...

Recent news: https://www.euspa.europa.eu/newsroom-events/news/galileo-get...

Not quite unspoofable, at least once the signal has been received for time-delayed rebroadcasting/meaconing.

But spoofing does become detectable by any receiver with a sufficiently accurate clock (I think for complete protection it would have to be an atomic clock though).

Any insight as to why newer GPS satellites do not offer similar capabilities?

The GPS project began in 1973. Digital signatures were invented in 1976. I'm guessing adding it on after the fact would have been very expensive.

There have been progressive improvements as new satellites are brought into service, and those end of life retired. Perhaps backwards compatibility?

https://en.wikipedia.org/wiki/GPS_signals#Legacy_GPS_signals

https://en.wikipedia.org/wiki/GPS_signals#Modernization_and_...