Rational secure computation and ideal mechanism design

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 ballot-box-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.