Secure Computation essentially guarantees that whatever computation n players can do with the help of a trusted party, they can also do by themselves. Fundamentally, however, this notion depends on the honesty of at least some players.

We put forward and implement a stronger notion, Rational Secure Computation, that does not depend on player honesty, but solely on player rationality. The key to our implementation is showing that the ballotbox -the venerable device used throughout the world to tally secret votes securely can actually be used to securely compute any function.

Our work bridges the fields of Game Theory and Cryptography, and has broad implications for Mechanism Design.