Key management for military GPS receivers I wonder what encryption scheme is used in high-precision encrypted GPS streams (the so-called “P(Y) code”). If there's a master key needed, then it has to be in every device. Yet the master key doesn't seem to have ever leaked (unlike like game consoles or Apple devices).

So what could explain why military-precision channel GPS receivers haven't been hacked yet? How does the protocol work?
Am I going to regret posting this? There seems to be enough non-classified information available about GPS to answer this question.

I see 3 reasons why P(Y) encryption is different and less likely to be hacked than game console encryption:


Hardware containing the GPS decryption key is more difficult to obtain than hardware containing the game console decryption key.
Now that selective availability is turned off, even civilian receivers have positioning accuracy about as good as military receivers -- eliminating the biggest benefit of obtaining the GPS decryption key.
(The other abilities that key gives a person -- receivers that are more resistant to spoofing, and spoofing transmitters that can cause even anti-spoofing military receivers to give bad location data -- are useless unless someone broadcasts spoofing transmissions, which for various reasons few people are willing to do).
From what I read on Wikipedia about the selective availability anti-spoofing module (SAASM) and the previous PPS-SM system,
there is apparently no master key.
Periodically a fresh new (and I suspect completely unguessably random) key is generated, distributed to all military units that require it, and then uploaded to the GPS satellites.
After that the old key is pretty much useless.
So even if one GPS decryption key did leak, it would only be useful for a short time.