Slashdot Mirror
Tor Open To Attack
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."
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."
welcome our onion-sniffing overlords!
Tor find this NOT FUNNY!!!
It's not really a troll, a troll is designed to draw a hostile reaction.
"I felt a great disturbance in the Internet, as if millions of child-pornographers suddenly cried out in terror and were suddenly silenced. I fear something terrible has happened."
Now now, I know Tor isn't just used for naughty stuff. I just thought it was funny. Sorta.
"Better to be vulgar than non-existent" -Bev Henson
In Soviet Russia, Tor attacks YOU!
"We show that even if an adversary can control a few malicious nodes -- 3 to 6 with a PlanetLab network of 60 honest servers -- the adversary can still compromise the identity of a significant fraction of the connections from new clients."
3 to 6 servers out of 60 is still 5 to 10 percent. That's fine for small networks, but for a network with hundreds or thousands of nodes, controlling 5 to 10 percent may become infeasible. Does this attack require the number of nodes to scale with network size?
We all know what to do, but we don't know how to get re-elected once we have done it
we need to attack child pornographers and irc abusers who hide behind tor
possibly a pre-emptive strike before they over run tor
Budget Value Weiners?
So, ze kiddie porn is on vor mind, eh Social Engineer? Very interesting. Who besides grandstanding politicians, media whores and actual pedophiles actually thinks or talks about kiddie porn? You must be one of the bag guys. The FBI vill be watching everything you do for the next ten years.
Friends don't help friends install M$ junk.
n/t
...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.
From what I can tell, it sounds like an attack can be either minimized or avoided completely if there are enough "server" nodes in the network. The "server" nodes, or the nodes that are exposed to the potential naughtiness, are always in short supply due to people understandably not wanting the FBI to show up to their door, hauling them off to Guantanamo Bay for a round of government-sanctioned torture. The thing is, for the time being, we're seeing a proliferation of completely open (untraceable) wireless networks that could potentially solve this problem. If a relatively large number of geeks were to throw a machine at their local free wireless connections, then they could potentially help out the TOR network for people who don't have access to such an "open" network. Now, we will eventually see these wide open free-for-alls shut down once the feds get their heads out of their asses and start taking Net-based crime seriously. But for the time being, we should all pitch in and take advantage of these networks while we've got 'em. I'm working on putting together a few Frankenstein PC's now and they'll be sitting within range of my town's wireless network, and they'll be routing TOR traffic. If somebody does some truly nasty stuff, and it comes out via one of my TOR nodes, then all the federales will be able to see will be the MAC addresses of my network cards, and have no idea where to find said network cards on the wireless network.
I don't respond to AC's.
Oh wait that would be Thor. Never Mind.
There are possibly more productive solutions to your problem than anonymous ranting on slashdot.
Rob had better order the Orbots to unite as Mighty Orbots. That will be the only way to eliminate that vulnerability.
Don't forget the Chinese Dissidents.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
Who's Roger Dingledine?
How do you hide the computers? How do you keep them from getting wet? What are Frankenstein PC's? How do you supply power to these computers?
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.
here's an easy fix, although could hurt your speed / other issues
"technically, the compromised nodes are the entry and exit nodes"
ExcludeNodes nickname,nickname,...
EntryNodes nickname,nickname,...
ExitNodes nickname,nickname,...
HttpsProxy host[:port]
Tor will make all its OR (SSL) connections through this
host:port (or host:443 if port is not specified), via HTTP CON-
NECT rather than connecting directly to servers. You may want
to set FascistFirewall to restrict the set of ports you might
try to connect to, if your Https proxy only allows connecting to
certain ports.
Hey fucktard, it stand for The Onion Router...get it?
Gerry
Some military broadband links send a constant stream of encrypted data, whether real data or filler. This "hiding in plain sight" reduces the ability of someone to perform traffic analysis on the network in precisely such a manner. This would be awful on the Net, of course, if everyone did it. But people should be aware that encryption is not the only facet of communications security that they need to worry about.
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.
Come on, if you're going to troll, at least put some effort into it. Nowhere in the summary is it mentioned that Tor is an acronym. It's not written as TOR. Those ignorant of the project would assume that it was just a silly name.
LOAD "SIG",8,1
If you don't know what tor is, and can't RTFG, you don't belong on slashdot.
What changed under Obama? Nothing Good
To anyone not in the know, the fact that the TOR protocol has a weakness means absolutely NOTHING regardless of whether they know what TOR stands for or not.
Granted, there is such a thing as TLA-overload...but I don't think this is it. If you don't know that TOR stands for The Onion Router, then why the hell do you care whether it is vulnerable to attack or not? You obviously aren't using it... You don't care about the technology or implementation... You are apparently not even curious enough to Google it... So why bother clicking through to post such a rant?
"Work is the curse of the drinking classes." -Oscar Wilde
Hmmm... I'm sure Freenet didn't get this much attention when they discovered that their encryption code was only actually encrypting half the data (128 bits out of every 256 bit word). Must be because no-one actually uses Freenet...
Would it be possible for a tor exit node to apply automatic filters to requests and replies so that the usefulness for illegal porn and criminal activity is reduced ?
Hey don't blame me, IANAB
I learned about these attacks on Tor in my computer security class last semester. And we're making a big deal now? Maybe my comp sci professor should get some sort of award for discovering it first.
I have just configured my Tor and know you guys says doesn't work? Does I take that long setting up everything? damn... :/
ghostbar page.
Now people want to take a way to get around filters and FILTER it...
Tor has never really provided much "anonymity." In fact from what I've seen, the most frequent use of Tor is for people to pipe through another IP address to avoid bans/troll websites/flood IRC channels...the list goes on. Why do you think so many of the exit servers are banned from even connecting to a lot of sites/IRC servers?
I'm glad someone finally came out and exposed this piece of software as being a failure at what it intended to be.
What do I, or Joe, or dedazo, or any of the other user names you intentionally misspelled, have to do with your parent comment?
Oh, I know. Hate.
Take it from a former card-carrying member of Team OS/2: Once you put what you hate ahead of what you love, you are lost.
This sig intentionally left blank.
Please check out http://blogs.law.harvard.edu/anonymous/2007/02/26/ the-rumors-of-our-demise/ for The Tor Project's official response to this paper.
Shava Nerad
executive director
The Tor Project