Game Theory With Costly Computation



Rafael Pass
Cornell, Department of Computer Science

Monday  February 16, 2009
4:00 PM, 5130 Upson Hall



We develop a general game-theoretic framework for reasoning about strategic agents performing possibly costly computation. In this framework, many traditional game-theoretic results (such as the existence of a Nash equilibrium) no longer hold. Nevertheless, we can use the framework to provide psychologically appealing explanations to observed behavior in well-studied games (such as finitely repeated prisoner's dilemma and rock-paper-scissors). Furthermore, we provide natural conditions on games sufficient to guarantee that equilibria exist.

As an application of this framework, we consider a notion of game-theoretic implementation of mediators in computational games. We show that a special case of this notion is equivalent to a variant of the traditional cryptographic definition of protocol security; this result shows that, when taking computation into account, the two approaches used for dealing with deviating players in two different communities---Nash equilibrium in game theory, and zero-knowledge simulation in cryptography---are intimately connected.

Joint work with Joe Halpern.