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There is a separate encrypted GPS signal, which used to have better precision as the public signals had intentional noise added to them. Of course, GPS is a ra
by revelation 10y ago
There is a separate encrypted GPS signal, which used to have better precision as the public signals had intentional noise added to them.
Of course, GPS is a rather old system and I'm unclear how you would add encryption in a way that it's not compromised when someone gets access to a decoder but also doesn't endanger "mission success" because a encryption key punch card is missing and the drone refuses to start. It's like the nuclear launch codes being all zeroes.
- tjohns 10y agoAs I understand it, encrypted GPS (L2) does depend on key material being periodically loaded from a fill device for proper operation. The keys are rotated periodically, so if somebody stole a decoder, it would only work until the key in memory expires. (Military GPS receivers also have a "zeroize" button to destroy the keys in case of imminent capture.)