Slashdot Mirror
Computer's Heat May Unmask Anonymized PCs
Virtual_Raider writes "Wired is carrying a story about a method developed by security researchers to identify computers hiding behind anonymity services. From the article: 'His victim is the Onion Router, or "Tor" — a sophisticated privacy system that lets users surf the web anonymously. Tor encrypts a user's traffic, and bounces it through multiple servers, so the final destination doesn't know where it came from. Murdoch set up a Tor network at Cambridge to test his technique, which works like this: If an attacker wants to learn the IP address of a hidden server on the Tor network, he'll suddenly request something difficult or intensive from that server. The added load will cause it to warm up.'"
Close, but no cigar.
His software lets you pinpoint servers in the anon TOR network, good trick, but ultimately useless (since its the users computer you are trying to find).
Of course the other problem is "giving it a heavy load" define heavy load? is it just a little more than usual? or does it mean you have to heat board (he goes off system clock, maintained by a frequency crystal on the MB), most data centres I would think would be fairly efficient at routing even high heat loads out of enclosures and away from the machine.
And then, whoever he does this to can sue him for DoSing their machine, if they can prove (and its not overly difficult) that heat damages computer parts, he can be nabbed for wilful destruction of property as well, since his whole exercise heats the machine for no other reason than locating it.
Then of course, the only way to "heat up" said computer is to do it through the TOR api, which i am guessing most anon servers are built to handle very well (since that would be their primary task).
Oh, and this of course neglects to take into account that your TOR requests may be handled by many many servers in a cluster, each one heating and skewing at different rates...
Ok, its late on a Saturday afternoon and I can poke that many holes in his trick (even if only one is at all real), gimme a good 2-3 hours with some energy drinks in me and I can find more I am sure ^_^
If he can prove it works (and successfully do something usefull with it) in the real world, then it would be a better story.
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