Users Get Routed: Trafﬁc Correlation on Tor by Realistic Adversaries [pdf]

http://www.ohmygodel.com/publications/usersrouted-ccs13.pdf

by tcoppi • 13 years ago

71 32 13 years ago

HPLovecraft3• 13 years ago

IIRC, Tor was built by the US Naval Research Labs, so... yeah one should assume its compromised.

Karunamon• 13 years ago

That makes no sense - it's like saying SELinux is compromised because it was developed by the NSA. They use these tools internally.

balabaster• 13 years ago

You would assume the versions of anything the NSA uses is significantly modified or different than the versions in public... these guys [allegedly] have the best cryptographers, mathematicians and programmers in the world on their payroll. You can assume that anything you have in your hands is either completely insecure or only trivially secure in comparison to anything the NSA has.

I'm willing to bet that the best security mechanisms you have at your disposal have been cracked, breached or otherwise compromised. I wouldn't be at all surprised to hear that they hold secret mathematical breakthroughs that render half or all of the encryption algorithms the public are aware of useless.

hollerith• 13 years ago

If they intentionally included flaws when they originally developed it, then what is your explanation for why are they now informing the public of flaws?

The Naval Research Lab employs 3 of the 5 authors of the paper we are discussing. One of those authors (Syverson) was an original developer of Tor.

HPLovecraft3• 13 years ago

http://en.wikipedia.org/wiki/Limited_hangout

betterunix• 13 years ago

The Internet was originally funded by DARPA. Must be a trap!

Tor is not controlled by the US government. Moreover, Tor was originally created to protect US government spies in foreign countries; a deliberate compromise would have done far more harm to government interests than good.

Create• 13 years ago

Moglen at Re:Publica: Freedom of thought requires free media

On the other side was the then deputy attorney general of the United States and a lawyer in private practice named Stewart Baker who had been chief council to the National Security Agency our listeners and who was then in private life helping businesses to deal with the listeners. He then became later on the deputy for policy planning in the Department of Homeland Security in the United States and has much to do with what happened in our network after 2001

and anyway the four of us spent two pleasant hours debating the right to encrypt and at the end their was a little diner party at the Harvard faculty club and at the end after all the food had been taken away and the pork and the walnut were left on the table Stuart said,

"All right, among us now we that we are all in private just us girls all let our hair down" he didn’t had much hair even then but he let it down "We are not going to prosecute your client Mr Zimmermann he said public key encryption will become available we fought a long loosing battle against it but it was just a delaying tactic" and then he looked around the room and he said "But nobody cares about anonymity do they?"

And a cold chilled went up my spine and I thought alright Stuart and now I know you’re going to spent the next twenty years trying to eliminate anonymity in human society and I am going to try to stop you and let’s see how it goes.

And it’s going badly.

We didn’t built the net with anonymity built in. That was a mistake now we are paying for it.

Our network assumes that you can be tracked everywhere.

And we have taken the Web, and we made facebook out of it.

We put one man in the middle of everything.

http://benjamin.sonntag.fr/Moglen-at-Re-Publica-Freedom-of-t...

coldtea• 13 years ago

The Internet was originally funded by DARPA. Must be a trap!

Well, intended or not, it IS a huge trap.

rsync• 13 years ago

The genesis in the US Navy is not so relevant as the current and regular funding that the project gets from the us government.

I don't think it's paranoid at all to greet that with healthy skepticism...

seandhi2• 13 years ago

We always knew that correlation attacks by an adversary that controlled a sufficiently large portion of the Internet were trivial to carry out. Now that we've learned that the NSA is capturing 75% of Internet traffic then we should assume that they are able to carry out correlation attacks fairly trivially, right?

kylemaxwell2• 13 years ago

Yes, but I have observed multiple times that many engineers, including crypto and even infosec folks, don't really understand or even think about traffic analysis as a threat vector. I want to chalk this up to a lack of thinking about systems (in the classic sense, not in the jargon for "computer" sense), but I'm not entirely sure.

blake8086• 13 years ago

Yes, from a T/A perspective, basically everything everyone uses leaks like a sieve.

A great paper about T/A: http://cryptome.org/2013/07/nsa-traffic-analysis.pdf

mike-cardwell• 13 years ago

If the NSA is your adversary then you have bigger problems. If the NSA isn't, then Tor is probably "good enough".

karlmdavis• 13 years ago

Do you have a citation for the 75% number? The last one I'd seen was 3% or 4%.

seandhi2• 13 years ago

To be fair, this says "reach" not "capture", but I have no idea what any of the words mean nowadays.

http://m.us.wsj.com/articles/a/SB100014241278873241082045790...

ebbv2• 13 years ago

Call me paranoid but I've always assumed Tor was a honeypot.

Finster• 13 years ago

It's not paranoia if they really are out to get you.

badman_ting• 13 years ago

This strikes me as a meaningless statement. But if you don't want to use it, hey, different strokes.

ebbv2• 13 years ago

Since the meaning apparently eluded you let me spell it out;

Tor seems like the perfect honeypot for government agencies looking to lure people who are involved in illegal activities online (child porn, drug trafficking, stolen credit cards, black hat hacking, etc.) Its origin is also well known to be based in government research. The source/identities/ownership of the various Tor nodes is by design unclear as being "safe".

In other words, if I were working for the NSA or FBI or whatever and designing a honeypot to lure in as much illegal activity online under a guise of safety and security but enable me to fully track it, I would design something like Tor.

munin• 13 years ago

Yes, an open-source, independently-verified and analyzed, and community-maintained honeypot. How exactly does that work?

Unless you want to call people like Roger Dingledine and Jake Appelbaum agents of the state (Jake has been called many things, but I can never imagine anyone seriously insinuating that there is a connection between him and any government).

peterwwillis• 13 years ago

Fun related paper: Locating Hidden Servers [http://www.onion-router.net/Publications/locating-hidden-ser...] Summary:

"Using random selection of backup and layering entry guard nodes will be an improvement, but as in all Tor circuits, someone connecting through ran- dom nodes will always be compromised if an at- tacker owns just two nodes [25]. Using the backup and layering techniques in combination with a non- random selection, e.g. based on some kind of trust, or experience, with the nodes, may slow the attack even more or may even prevent it entirely"

TIL: The Office of Naval Research has been working on onion routing for 18 years. http://www.onion-router.net/History.html

funkaster• 13 years ago

Yup, it is kind of prevented now (otherwise the Silk Road would've been shut down long ago). From the paper's conclusion:

"Our results show that Tor’s location-hidden servers are not really hidden—or rather they were not really hidden prior to the recent introduction of guard nodes as countermeasures to our attacks."

More info: https://www.torproject.org/docs/hidden-services.html.en (where they reference the same paper)

Users Get Routed: Trafﬁc Correlation on Tor by Realistic Adversaries [pdf]

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