On Apr 11, 2011, at 4:10 PM, Jeroen van Aart wrote:
http://www.newscientist.com/article/dn20336-internet-probe-can-track-you-dow... "The new method zooms in through three stages to locate a target computer. The first stage measures the time it takes to send a data packet to the target and converts it into a distance – a common geolocation technique that narrows the target's possible location to a radius of around 200 kilometres. (..) Finally, they repeat the landmark search at this more fine-grained level: comparing delay times once more, they establish which landmark server is closest to the target. The result can never be entirely accurate, but it's much better than trying to determine a location by converting the initial delay into a distance or the next best IP-based method. On average their method gets to within 690 metres of the target and can be as close as 100 metres – good enough to identify the target computer's location to within a few streets."
It seems to me to be a rather flaky way of finding out your estimated location. But I guess it could be helpful when the objective is just to create some global database of demographics for marketing and privacy invasion purposes, where specifics of an individual's exact location don't really matter.
The idea is to have finer and finer grained locations based on RTTs and a dense mesh of "landmark routers." Of course, if you were using a tunnel or proxy that took N msec of delay, the best they could say is that you were N msec from the tunnel endpoint. It would also be easy to institute something like the old GPS selective availability, with a software tunnel randomly adding a variable delay (say, varying by up to 50 msec every 100 seconds). Regards Marshall
Besides the latter can always be subpoenaed. ;-)
One more reason to use VPN and other such techniques to hide your location.
Greetings, Jeroen
-- http://goldmark.org/jeff/stupid-disclaimers/ http://linuxmafia.com/~rick/faq/plural-of-virus.html