PROG challange: fetish corroborator

write an algorithm that enables two persons over a communication channel to find out which fetishes from a preset list they happen to share.

it should done in such a way that no extra information is leaked, see http://en.wikipedia.org/wiki/Yao%27s_Millionaires%27_Problem to get started.

Bonus: Extra points are awarded to written in Lisp or Scheme.

Deadline: The deadline is 03/07/2015 so get cracking!

>>2
Dishonest? How about incorporating data collected by Google Analytics, Quantserve, Facebook, etc. rather than what they specifically input as their fetishes?
Get porn sites (Pornhub, Redtube, etc.) to partake in datamining and use tracking cookies and whatnot to find out what people are really into.
A user can lie, but a server's traffic logs do not.