Comment by thewebguyd | Hacker News Reader

Comment by thewebguyd | Hacker News Reader

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The feds and other equivalent agencies in other countries have been running exit nodes for years, but its still better than most solutions even if not perfect. Anyone who has gotten caught though likely wasn't because of any flaws in Tor (or said exit nodes) but because of other lapses in OpSec.

That being said, yes, feds can de-anonymize traffic, probably reliably at this point. There are only about 7-8000 active nodes, most in data centers. The less nodes you hop through, the more likely that traffic can be traced back to the entry point (guard node), and combined with timing can be reasonably traced back to the user. Tor works best with many, many nodes, and a minimum of three. There's not as many nodes as there needs to be so quite often it's only 3 you are going through (guard node/entry point, middle node, exit node)

Plus browsing habits can also be revealing. Just because someone is using Tor doesn't mean they also have disabled javascript, blocked cookies, aren't logging into accounts, etc.

> Anyone who has gotten caught though likely wasn't because of any flaws in Tor (or said exit nodes) but because of other lapses in OpSec.

There have been some cases where some consider the "other lapses in OpSec" to be parallel construction to disguise a Tor vulnerability/breach, and others where the government has declined to prosecute because they'd have to reveal how they know.

If Tor were compromised, we'd likely not know. It's highly likely that it's fine for "normal people" things.

At least back in the Snowden days it was very unreliable for the US to deanonymize Tor traffic based on those documents.

That was over a decade ago. They've almost certainly progressed since.

... now my back hurts and I want the damn kids off my lawn.

I mean if anything it’s harder today in many ways for the government than it was during the Snowden days, because that prompted tech people to take internet security seriously. Look at the cost trends for 0days over the past ten years.

This page on the mailing list has links to cases of people who were caught because of an unknown flaw in Tor: https://archive.torproject.org/websites/lists.torproject.org...

I can't find a link, but I think people have done simulations and the privacy benefits of more hops are not as great as one might think. If you control the guard and exit, then traffic confirmation is relatively easy by just looking at timing and volume of traffic no matter how many hops are in between.

Does controlling exit nodes necessarily help with deanonimizing? You would need control of the internal nodes for classic de-anonymization, or monitoring of both the exit nodes and the originating network for timing attacks. Also, exit nodes aren’t involved in hidden services. That 7-8000 figure you quoted: is that just exit nodes, or all nodes? My understanding was there aren’t a ton of exit nodes because anyone operating an exit node is liable to get harassed by people impacted by any malicious traffic originating from Tor. But that isn’t really an issue for internal nodes, and so there are more of them

Controlling an exit node alone doesn't help, but controlling both entry and exit nodes does.

The tor project has network stats on their website: https://metrics.torproject.org/networksize.html

Looks like about 8,000 relays, inclusive of entry and exit nodes. Looks like about 2,500 exit nodes, and ~5,000 guard nodes. With that few I'd say it's reasonable to assume that a large number of both entry and exit are controlled by government agencies, at least enough to reliable to conduct timing attacks against a specific target they are interested in.

Am also interested in the current understanding of culpability in the US for operating an exit node.

> Am also interested in the current understanding of culpability in the US for operating an exit node.

It's a little ambiguous.

Section 230 (which continues to be under attack) provides some legal immunity, along with the DMCA is a safe harbor against copyright infringement claims for the Tor relay operator. Running a middle relay is generally fine and safe.

But, running an exit relay is risky. Even if you can't be held legally liable for the traffic coming from the exit, you could still get raided, and it has happened before where exit node operators have been raided after the traffic coming out of it was attributed to the node owner.

That being said, it's legal to run an exit node (for now). The problem is more so dealing with the inevitable law enforcement subpoenas or seizures, and having the money and resources to prove you are innocent.

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