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Never attribute to malice that which is adequately explained by stupidity. Don't forget that USA military uses the encrypted P(Y)-code GPS signals, which can n
by fuoqi 5y ago
Never attribute to malice that which is adequately explained by stupidity.
Don't forget that USA military uses the encrypted P(Y)-code GPS signals, which can not be spoofed by adversary. Yes, they can be jammed, but IIRC modern military ships and planes equipped with very presice IMUs, so they are quite immune to a short-term GPS jamming. And even before that, spoofing or jamming which has caused such incident can be easily detected and it would have been immideately publicly reported.
- tialaramex 5y ago> Don't forget that USA military uses the encrypted P(Y)-code GPS signals Do they? The whole reason Selective Availability was switched off (and is no longer built-in at all) is that the same US military found that cheap civilian GPS was readily available while specialist military GPS was always back-ordered. > which can not be spoofed by adversary Those signals just need a (secret) key, they aren't Hollywood plot magic that prevents spoofing. Your annoying older brother doesn't have the US military secret key for GPS, but I see absolutely no reason to believe that the Russians have somehow never been able to obtain this key. The more you wriggle on the first point the more salient the second point becomes - if the US military has millions of military keyed GPS units, Russia could trivially steal one. And the less important the second point, the more the first applies - if Russia can't steal these keys because only a dozen military GPS units are deployed, there likely wasn't one feeding this (civilian anyway) AIS transmitter.
- fuoqi 5y agoSince I do not serve in the US military, I don't know for sure, but I would be really surprised if it was not the case, especially for ships and planes. I'd imagine keys are rotated on regular basis. If you think that Russia has a reliable access to those keys, then USA military has FAR bigger issues than hypotetical spoofing. And you have not adressed the second part of my comment. Not only we haven't heard about spoofing as a reason for those incidents, but also even with civilian recievers spoofing can be detected by comparing GNSS and IMU data. And even before that you can detect anomalous power of GNSS signal (since spoofing usually has to outpowr legitimate signal) or find that there are "satellites" which produce unconsistent signals.
- trhway 5y ago>If you think that Russia has a reliable access to those keys, then USA military has FAR bigger issues than hypotetical spoofing. btw, i don't think it was Russia, to me it looks like China who has much better access in particular to the technological layers of the US defense systems. Sailors on these destroyers at night were looking at those screens with "confusing UI" - you don't need to spoof GPS/etc. if you cracked the access to the UI, and that it was the same destroyer type fits well into it.
- ytpete 5y agoWouldn't this likely be using asymmetric encryption though? In that case obtaining the public key from a stolen receiver would only let you read the high-precision P(Y) signals – you couldn't spoof them since you still don't have the private key.
- sudosysgen 5y agoAnd yet, they have been spoofed in the past, multiple times, by opponents weaker than Russia. Instead of breaking the encryption, you just replay delayed signals.
- tialaramex 5y ago> Wouldn't this likely be using asymmetric encryption though? It isn't, but even if it was, not in a way that makes this attack significantly more difficult. The problem you have is that GPS receivers are receiving one or more bit streams and passively discerning their position from the timing of those bit streams. In something like TLS (except 0RTT early_data) both peers begin by introducing randomness to each session. So this connection must be the new connection I just created, if you try to send me packets from an earlier session, the random parameters are all wrong and it's unintelligible. Verifying this is called "freshness". In contrast a passive receiver can't check for freshness. It just has to believe whatever it is told, no choice. So, as an adversary I can spoof your position by simply feeding you stale data. I probably shouldn't try to persuade you this is actually the middle of the Pacific ocean not the Black Sea, nor that it's actually January rather than June, but I can certainly fudge things a little bit without too much trouble.
- sudosysgen 5y agoThere is no need to crack the key. You just need to replay the signals with variable per-satellite delay to shift the position however you want.