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Cake day: August 29th, 2024

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  • I was like 3 paragraphs into a writeup about response times, latency, probabilities, etc but I realized you already have all the information and can’t be reasoned with.

    You do know what I mean by “response time” right? The recieving computer gets the packets and sends word back. NOT the VPN node, the VPN is not unencrypting traffic to emulate a real computer, it’s instead just relaying the packets TO YOUR MACHINE. VPNs are not the perfect black box void immune to complicated analysis.



  • 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.


  • 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.


  • 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.