sniffing torrent data

[stig]

Is it possible to sniff the data being transferred between two utorrent client?

[Lord Alderaan]

Difficult question. The honest answer is Yes.

However the splitting of data into pieces makes it more difficult to make heads or tails from it. Even if one can sniff a single piece it is probably difficult to make something of this small piece of the puzzle that is the whole torrent.

And if the data is compressed (rarred) it becomes virtually impossible. The large majority of the pieces will have no identifiable information at all.

So in reality the answer is No, this is usually so difficult that it isn't practical.

Especially since simply joining swarms is a infinity better way to spy.

[stig]

It is obvious that utorrent knows how to pack pieces to form the final file. So if someone knows that algorithm, he can do like the utorrent.

Also how to join swarm?

[Lord Alderaan]

You said sniffing. That means a third person that monitors traffic (say with wireshark). For them the pieces thing is not as transparent as to µtorrent.

There is also protocol encryption to make it even more difficult.

You 'join a swarm' by loading a torrent in a bittorrent client and announcing to the tracker.