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Encrypted GPS do yu even make sense, what benefit an encrypted GPS will provide. Eu will know where were you when you requested something and even if your data

Encrypted GPS do yu even make sense, what benefit an encrypted GPS will provide. Eu will know where were you when you requested something and even if your data was encrypted and i don't think you can intercept gps coordinates and you have to intercept at least three for it to be useful.

detaro 7y ago
Yes, encrypted GPS makes sense. You can broadcast additional information that can be used for more precision only on encrypted channels, and have people pay for the decryption keys. (That's part of how the better-quality GPS for US military works) Another way is selling online access to better-quality correction data. Neither necessarily involves telling anyone where you are.
- bluGill 7y ago
  Even the US military doesn't use the encryption channels much anymore. Turns out that differential GPS is more accurate and you don't even need the encryption channel to do it. We already know the next message the GPS will send with high accuracy, the important part is detecting exactly when the first bit arrives at the antenna you everything you need from that. 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.
  - 420codebro 7y ago
    You couldn't be more wrong my lad. GPS is divided into two fundamental types of positioning services: 1) Precise Positioning Service (cool shit) 2) Standard Positioning Service (the shit you have access to) PPS (which is what the military uses) chirps at ten times the rate of SPS, eg for every 1 position update you get on SPS, you will get 10 from PPS in the same timeframe. Why is this useful? Imagine if you are flying 500mph... now maybe 2000mph.... yeah you get the idea. Yeah, you can use d-GPS to get really, really accurate resolution. But is it proven to work when I am dumping 5000 watts of jamming energy towards it? The reason the military will always have their own enciphered positioning data is they want to be able to shut off the public segment while still having their war-fighting capabilities. Also most GPS jamming stuff will target civilian frequencies - the target market.
- tialaramex 7y ago
  The encrypted channel just involves knowing a secret "key". This is in principle viable for high value military work, and you're right that Galileo has reserved such a channel. 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.
gnode 7y ago
> Eu will know where were you when you requested something 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.
- zimpenfish 7y ago
  > 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.
  - gnode 7y ago
    I agree, although I'm not sure whether it's ever been implemented for public use. 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.

detaro 7y ago

Yes, encrypted GPS makes sense. You can broadcast additional information that can be used for more precision only on encrypted channels, and have people pay for the decryption keys. (That's part of how the better-quality GPS for US military works) Another way is selling online access to better-quality correction data. Neither necessarily involves telling anyone where you are.

bluGill 7y ago
Even the US military doesn't use the encryption channels much anymore. Turns out that differential GPS is more accurate and you don't even need the encryption channel to do it. We already know the next message the GPS will send with high accuracy, the important part is detecting exactly when the first bit arrives at the antenna you everything you need from that. 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.
- 420codebro 7y ago
  You couldn't be more wrong my lad. GPS is divided into two fundamental types of positioning services: 1) Precise Positioning Service (cool shit) 2) Standard Positioning Service (the shit you have access to) PPS (which is what the military uses) chirps at ten times the rate of SPS, eg for every 1 position update you get on SPS, you will get 10 from PPS in the same timeframe. Why is this useful? Imagine if you are flying 500mph... now maybe 2000mph.... yeah you get the idea. Yeah, you can use d-GPS to get really, really accurate resolution. But is it proven to work when I am dumping 5000 watts of jamming energy towards it? The reason the military will always have their own enciphered positioning data is they want to be able to shut off the public segment while still having their war-fighting capabilities. Also most GPS jamming stuff will target civilian frequencies - the target market.
tialaramex 7y ago
The encrypted channel just involves knowing a secret "key". This is in principle viable for high value military work, and you're right that Galileo has reserved such a channel. 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.

gnode 7y ago

> Eu will know where were you when you requested something 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.

zimpenfish 7y ago
> 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.
- gnode 7y ago
  I agree, although I'm not sure whether it's ever been implemented for public use. 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.