http://dds6qkxpeiqvogt4y2fd7vtsxq6pvokekb2h4la7jd4iwl4ljuawu5qd.onion/wiki/Dev/Technical_Introduction
Also BitTorrent doesn't leak the IP (there is an online bittorrent leak tester), which of course should never be used through Tor (because it chokes Tor nodes), but for leak testing it was welcome. Right now we don't know of any leak tests which leaks the real IP. Whonix is safe (not affected) from Protocol leaks , like this the ones listed on Whonix against Real Attacks , Skype, Flash or BitTorrent.