  In the last two decades, there has been much effort in finding secure
protocols for two-party cryptographic tasks. It has since been discovered that
even with quantum mechanics, many such protocols are limited in their security
promises. In this work, we use stochastic selection, an idea from stochastic
programming, to circumvent such limitations. For example, we find a way to
switch between bit commitment, weak coin flipping, and oblivious transfer
protocols to improve their security. We also use stochastic selection to turn
trash into treasure yielding the first quantum protocol for Rabin oblivious
transfer.
