I'm just putting a shout out to David Wang who has been working tirelessly over the last week or two to implement encrypted transfers for MonoTorrent. I have to say, he's done a great job.
The current SVN has around a 90% complete implementation. As far as i can tell, there's still a bug in accepting incoming connections. Other than that, all that needs to be done is to make sure it works with more than just uTorrent and then it's good to go!