What's really interesting is that there are some commercial receivers out there that will use P(Y) Code even though they can't decrypt it. IIRC the weakness was

What's really interesting is that there are some commercial receivers out there that will use P(Y) Code even though they can't decrypt it. IIRC the weakness was something along the lines of the lower rate W code made it so that while you couldn't decrypt it you could still use it as a reference to increase the accuracy of the C/A code. E.G. P code 1001011010010110101010100010101 W code 00001111000000001111111100001111 And since it's modulated with the W code this would leak information. Not really sure how off base that part is, that's just a rough explanation I was told many years back.