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Tor Open To Attack

Posted by kdawson on from the peeling-the-onion dept.

An anonymous reader writes "A group of researchers have written a paper that lays out an attack against Tor (PDF) in enough detail to cause Roger Dingledine a fair amount of heartburn. The essential avenue of attack is that Tor doesn't verify claims of uptime or bandwidth, allowing an attacker to advertise more than it need deliver, and thus draw traffic. If the attacker controls the entry and exit node and has decent clocks, then the attacker can link these together and trace someone through the network."

5 of 109 comments (clear)

  1. Well, not just that. by James_Duncan8181 · · Score: 4, Interesting

    If the attacker advertises absolutely massive values (and hey, it's only a string) they can time out all of the packets and DoS the network too.

    This actually makes me wonder if there is a military/intel datacentre that does this already.

    --
    "To any truly impartial person, it would be obvious that I am right."
    1. Re:Well, not just that. by Kadin2048 · · Score: 5, Interesting

      The military and secretive NSA operations do not care about you or your open source proxy software. Stop trying to make yourself feel special by writing convoluted conspiracy theories.

      No, but the Chinese equivalent of the FBI probably cares a lot about what its citizens are doing on the net, and the ability of users living under hostile regimes to get unfettered network access is one of the goals of projects like Tor.

      There are people with resources besides the NSA.

      --
      "Ladies and gentlemen, my killbot features Lotus Notes and a machine gun. It is the finest available."
  2. Anonymity Vs Performance in Multi-Hop Networks... by Roger+Wilcox · · Score: 5, Interesting

    ...is really what the article is about. Granted, I only read the abstract, but someone here at /. seems too intent on making a dramatic headline out of this.

    It has been known for some time that anyone with the resources to do so could launch an end-to-end attack on Tor. That someone with relatively few resources could launch the same attack is newsworthy, perhaps, but far more interesting is the observation that optimizing network traffic flow in order to improve performance is the direct cause of this weakness.

  3. COMSEC, not SIGINT by dr.badass · · Score: 4, Interesting

    This actually makes me wonder if there is a military/intel datacentre that does this already.

    Probably, but not for the reasons you think. Tor is known to be used by the military (how much is anybody's guess) for the same reasons anybody else would use it.

    --
    Don't become a regular here -- you will become retarded.
  4. Even if you can't become both the entry/exit... by twistah · · Score: 4, Interesting

    Even if you aren't able to become both the entry and exit mode, using the technique of faking your bandwidth/uptime can lead to more traffic for your exit node, which means more passwords to sniff. Not everyone seems to realize that just because the Tor protocol is encrypted doesn't mean the exit node can't sniff unencrypted traffic. Granted, the exit node has no idea where the traffic came from, but often information such as login information for a personal account can give that away. That's even better than having just an IP. All it takes is to set yourself up as a Tor node (the uptime/bandwidth faking helps) and run a tool like Cain or dsniff.