[anti-censorship-team] Identify from which continent people connect from

[David Fifield]

On Mon, Mar 20, 2023 at 03:31:23PM -0600, mxz+tor-anti-censorship-team--- via anti-censorship-team wrote:
> recently, there was an interesting side note on the cryptography mailing
> list [1].
> Quote:
> 
> > (People have written code to predict what continent an anonymous person
> > using Tor is on, based on noticing over a period of time when
> their remote system clocks ran faster or slower, assuming that was caused by
> nighttime versus daytime temperatures.)
> 
> I was wondering if any of you know about this and where I could find code
> that does this? Any links to research and papers would be highly
> appreciated, too.
> 
> Especially, I'm wondering how they do this:
> 
> - via differences in the above mentioned system clock (impressive?!)
> - timing analysis with latency? things like lower latency in Europe as there
> are more tor relays around compared to Argentina.
> - do you need to have any prerequisites? e.g. controlling at least one node,
> or the exit node, or a "clear text" server/hidden service that someone
> connects to?

It sounds like they are referring to "Hot or Not: Revealing Hidden
Services by their Clock Skew" from 2006.

https://www.freehaven.net/anonbib/#HotOrNot

Section 5.3 is about geolocation.

> Longitude could simply be found by finding the daily peak temperature
> to establish local time. To find latitude, the change in day length
> over a reasonably long period could be used. ... national holidays or
> when daylight saving time comes into effect might be evident