

Bittorrent over Tor isn't a good idea - Garbage
https://blog.torproject.org/blog/bittorrent-over-tor-isnt-good-idea

======
Groxx
Super Simple Summary:

1) Torrent applications don't always respect your proxy settings, bypassing
Tor entirely.

2) Torrent applications sometimes add your IP address to their packets, so you
essentially tell everyone where you are after coming out of a different door
all sneaky-like.

3) You're probably telling all this and your port number to the tracker.
Trackers are complete blabbers, they'll tell anyone who asks where to find
you.

4) Multiple connections run through a single "circuit" for speed & a bit of
anonymity (by reducing the number of nodes you're using, some of which may be
watched; I don't quite follow this reasoning. Seems to me it's putting all
your eggs in fewer baskets), but browsing + torrent may reveal enough info to
deanonymize you, because you run through fewer exit nodes.

And last but not least, Tor can't handle the load:

> _We've been saying for years not to run Bittorrent over Tor, because the Tor
> network can't handle the load._

Running torrents over Tor has always been a horrible idea, due to the load
issues and 2 and 3. And because it's insanely slow. And because it's about as
rude as you can possibly be to the rest of the Tor network. The fourth is new
to me. I suspect most of the offenders just don't fully understand torrents or
Tor, and are reaping what they sowed - there are plenty of resources to
understand it, and Tor goes to great lengths to explain what it does
_extremely_ clearly.

------
martey
It is worth noting that both this Tor blog post, and the research paper it
mentions, were published in April 2010. I initially assumed that this would be
explaining why using Bittorrent with Tor hurts the network, like
[http://www.chrisbrunner.com/2006/07/09/why-you-shouldnt-
run-...](http://www.chrisbrunner.com/2006/07/09/why-you-shouldnt-run-
bittorrent-over-tor/) :

 _When you use BitTorrent on Tor, you're placing an incredible amount of
burden on the network and sucking up the bandwidth that could have otherwise
been used for the purpose of freely spreading information. You're discouraging
people from donating their bandwidth to running the exit nodes that allow the
Tor network to function. You're destroying everyone's ability to publish
information without being persecuted by their government. You're destroying
the privacy that so many people worked so hard to give us._

------
mike-cardwell
Whilst I agree that the Tor network would be better off without Bittorrent
traffic, it bothers me when I read things that say that Tor can't anonymise
Bittorrent traffic.

[https://trac.torproject.org/projects/tor/wiki/TheOnionRouter...](https://trac.torproject.org/projects/tor/wiki/TheOnionRouter/TransparentProxy)

Using the TransparentProxy mode of Tor, forces _all_ network traffic out
through Tor, and blocks stuff which can't be, such as UDP. Do that on a
machine which only has a LAN address so doesn't know it's Internet facing IP,
and it's anonymous... It can't leak it's IP because it doesn't know it, and it
can't connect to the Internet without going via Tor...

~~~
thecoffman
Yes, but the article states that some torrent software actually appends your
IP address information to the packets themselves, so even if they emerge from
an exit node on the other side of the world, entirely anonymized, simple
packet inspection can determine their origin.

~~~
mike-cardwell
How does the software append your IP address if it doesn't know it? It can't
get it from your router via UPNP, because that traffic is blocked. If it tries
to get it by connecting to some online service and asking the IP, the IP it
gets back is the Exit nodes.

It _doesn't know_ it's IP address, so it can't leak it.

~~~
thecoffman
Hrm, I see what you're saying - that is an interesting question. I'm not
actually sure of the answer.

~~~
mike-cardwell
The answer is, it doesn't. This is why it is completely anonymous to use Tor
with Bittorrent, but _only_ if you use a transparent proxy configuration.

------
nuada
This is a prime example of people stacking complex tools together and
expecting properties to magically combine. It doesn't work that way in the
real world, it doesn't work with "computers". I may be an angry old fart, but
this "screw knowledge, screw others, live in a dream" mentality is starting to
annoy me.

~~~
pjscott
Sometimes, if the tools are designed really well, they do combine. Witness the
success of Unix pipelines, or the nigh-magical ability of TCP to work over
Ethernet, Wifi, a modem, or whatever other complex systems people dream up.

Being able to combine complex systems is a _good_ thing, and it shouldn't be
disparaged as unrealistic.

~~~
xyzzyz
Applications communicating via Unix pipelines indeed do frequently combine,
albeit rarely without great amounts of awk/grep/sed glue and reimplementation
of parsing machinery in every link in a chain.

I don't say that pipelines are bad, it's just sometimes we want more
structured data format than flat text.

Also, Unix pipelines are currently in decline, and Unix itself is less Unixy
than it used to be.

~~~
bingaman
Unix pipelines are currently in decline

Citation needed

------
reyk
If you really want Tor-style anonymity with BitTorrent, I suggest I2P.
<http://www.i2p2.de/>

The core router software even bundles its own BitTorrent client. However,
since it is effectively a darknet, regular torrents you find elsewhere won't
really work. Still, it is interesting stuff.

------
steipete
They really just should block BitTorrent. It's overloading an already slow Tor
Network with stupid people downloading porn and piracy.

No seriously. I know BitTorrent is also used legally. But there are other,
less invasive ways to share files in Tor.

~~~
mike-cardwell
I've found that Tor is a lot faster these days than it was a year or more ago.
It's actually quite usable for general browsing.

