Given that the project is funded by €10 billion of EU taxes, I hope we'll get transparency sooner rather than later on exactly what's gone wrong, regardless of who it might embarrass.
[0] https://www.gsa.europa.eu/newsroom/news/update-availability-...
> A technical incident in the Galileo ground infrastructure is affecting the functioning of the Galileo system, as a result of which there is a temporary interruption of some of the Galileo initial services.
> The cause of the technical incident is identified and recovery actions are implemented to ensure that the nominal service is resumed as soon as possible while safeguarding quality of the services.
Pretty sure universities and other institutions would be able to inquire though.
Another way is selling online access to better-quality correction data.
Neither necessarily involves telling anyone where you are.
If you want to get more accurate you don't use the encrypted channel you put a GPS in a fixed location on earth and have it send corrections to you. (called RTK)
Edit: Note that I have no information on what the US military uses their classified channel for. It is unlikely they get any accuracy information from it anymore given what civilian GPS systems have figured out.
In practice the Americans learned that COTS dominates for electronics. You can buy 100 of the special military product with the secret key, delivery in 18 months or for the same price you can have 5000 of the generic civilian product, 10 days lead time.
So these secret extra channels are of dubious value. But they're cheap to implement so they remain something new GPS style systems have.
In theory keeping the key secret defends against a sophisticated adversary spoofing your signal. But there's an obvious trade, if you only make ten units you can probably ensure the adversary doesn't capture one, but it's not very useful. If you make a million units that's initially more useful but your adversary will definitely get the key.
You don't request a positioning signal, they are broadcast by the satellites and nothing is sent back by the receivers. Some devices (like smartphones) may send their GPS discovered position over the Internet, where encryption may be used, but this is not what is being referred to.
Encryption allows you to restrict access, or provided tiered access to signals of varying accuracy. You can also use cryptography in order to prevent spoofing.
I think that's probably the biggest selling point given how many important infrastructures rely heavily on GPS these days.
You get anti-spoofing naturally if you're just using secret symmetric encryption (if your adversary doesn't know the key, they can't generate a valid signal to trick you with). To prevent spoofing against the public, you'd need to make use of public-key cryptography.
That's the plan (or at least something explicitly reserved as an option), yes.
Encrypting what?
Except if you want people not to be able to use the GPS signal, which sure make sense in military context (and even then, it's pretty meaningless, except if you change the key pretty regularly and you have a safe way to propagate it that won't be possible for enemies to get their hands on).
You know right that GPS signal is a one way signal? The receiver doesn't transmit anything, he just receive and use the timing and its data with some fancy math to be able find your position.
As a result, while we have sub-5ft accuracy now, there's no guarantee that in war time, we won't lose that.