Another thing that only very large companies can do is see the response time and compare packet size from different servers to narrow down your location, effectively defeating the VPN in a lot of cases.
Hypothetically, a specific amount of bytes gets sent to server B, response time indicates it was received 300 miles away which matches the response time of going from Server B to Server A where the user lives.
Of course it’s still important to use a VPN, if only because those big companies don’t want us to.
The latency to your VPN server is a constant added to the latency between your VPN server and whatever servers you are connected to. As long as the user’s VPN service doesn’t use different VPN servers for different destinations, it is impossible to determine the location of the user behind the VPN based on latency, and in general it is impossible to determine how far a user is from their VPN server because of varying latency introduced by the user’s own network or by bad infrastructure at the local ISP level. You can only know how far they aren’t based on the speed of light across the surface of the earth.
But, without a VPN, this is a real attack that was proven by a high school student using some quirks of Discord CDNs. Even without using Discord’s CDNs, if somebody wanted to locate web visitors using this technique, they could just rent CDN resources like nearly every big company is doing. Of course, if you have the opportunity to pull this off, you normally have the user’s IP address and don’t care about inferring the location by latency. The reason why it was notable with Discord was because the attacker was not able to obtain the victim’s IP address.
You say what I described is impossible but it’s been demonstrated by researchers such as “CPV: Delay-Based Location Verification for the Internet” by AbdelRahman Abdou with the Department of Systems and Computer Engineering, Carleton University Ontario.
Furthermore, on top of that method, if a company has access to data from servers in multiple places along the chain between endpoints, then they can see that a series of packets of specific size are traveling in a specific direction, narrowing down the location of the other endpoint. A company like Amazon, whose AWS servers make up almost 30% of the internet.
One of the more convoluted methods to defeat this approach was to simply add more stops along the chain, fragment the encrypted data into multiple parts, and pass it along random paths to the endpoint. I believe, but I could be wrong, that Tor utilizes this method. The problem with that is: it’s slower.
Yeah there was a cool paper on Delay Response method by AbdelRahman Abdou with Department of Systems and Computer Engineering, Carleton University called “CPV: Delay-Based Location Verification for the Internet”.
The other method I mentioned, checking packet size and general direction, would require accessing data along multiple stops before reaching the other endpoint with which to compare the sizes of encrypted data packets and use that to identify what is traveling where, which either has not been demonstrated or the companies utilizing it haven’t admitted to it, yet. It’s not a stretch to think it’s happening, though, with massive companies like AWS and CloudFlare or telecom giants like AT&T.
I imagine they could compile large datasets of ping times and server locations and do some extrapolation. I don’t think it ever goes past a best guess but they’d have an idea (if what this person said actually happens).
Companies dont really need to know where you are. They just need to know where you aren’t. If you are not within a certain threshold of response time to certain cdn servers, then its reasonable to assume that you are outside their contractually obligated broadcast region.
Another thing that only very large companies can do is see the response time and compare packet size from different servers to narrow down your location, effectively defeating the VPN in a lot of cases.
Hypothetically, a specific amount of bytes gets sent to server B, response time indicates it was received 300 miles away which matches the response time of going from Server B to Server A where the user lives.
Of course it’s still important to use a VPN, if only because those big companies don’t want us to.
The latency to your VPN server is a constant added to the latency between your VPN server and whatever servers you are connected to. As long as the user’s VPN service doesn’t use different VPN servers for different destinations, it is impossible to determine the location of the user behind the VPN based on latency, and in general it is impossible to determine how far a user is from their VPN server because of varying latency introduced by the user’s own network or by bad infrastructure at the local ISP level. You can only know how far they aren’t based on the speed of light across the surface of the earth.
But, without a VPN, this is a real attack that was proven by a high school student using some quirks of Discord CDNs. Even without using Discord’s CDNs, if somebody wanted to locate web visitors using this technique, they could just rent CDN resources like nearly every big company is doing. Of course, if you have the opportunity to pull this off, you normally have the user’s IP address and don’t care about inferring the location by latency. The reason why it was notable with Discord was because the attacker was not able to obtain the victim’s IP address.
You say what I described is impossible but it’s been demonstrated by researchers such as “CPV: Delay-Based Location Verification for the Internet” by AbdelRahman Abdou with the Department of Systems and Computer Engineering, Carleton University Ontario.
Furthermore, on top of that method, if a company has access to data from servers in multiple places along the chain between endpoints, then they can see that a series of packets of specific size are traveling in a specific direction, narrowing down the location of the other endpoint. A company like Amazon, whose AWS servers make up almost 30% of the internet.
One of the more convoluted methods to defeat this approach was to simply add more stops along the chain, fragment the encrypted data into multiple parts, and pass it along random paths to the endpoint. I believe, but I could be wrong, that Tor utilizes this method. The problem with that is: it’s slower.
This…sounds a bit like bs. Can you share a more detailed writeup? At best you could get a radius, but that wouldn’t really be helpful
Yeah there was a cool paper on Delay Response method by AbdelRahman Abdou with Department of Systems and Computer Engineering, Carleton University called “CPV: Delay-Based Location Verification for the Internet”.
The other method I mentioned, checking packet size and general direction, would require accessing data along multiple stops before reaching the other endpoint with which to compare the sizes of encrypted data packets and use that to identify what is traveling where, which either has not been demonstrated or the companies utilizing it haven’t admitted to it, yet. It’s not a stretch to think it’s happening, though, with massive companies like AWS and CloudFlare or telecom giants like AT&T.
I imagine they could compile large datasets of ping times and server locations and do some extrapolation. I don’t think it ever goes past a best guess but they’d have an idea (if what this person said actually happens).
Companies dont really need to know where you are. They just need to know where you aren’t. If you are not within a certain threshold of response time to certain cdn servers, then its reasonable to assume that you are outside their contractually obligated broadcast region.