Verifying Dominant Strategy Equilibria in Auctions

Future agent mediated eCommerce will involve open systems of agents interoperating between different institutions, where different auction protocols may be in use. We argue that in order to achieve this agents will need a method to automatically verify the properties of a previously unseen auction protocol; for example, they may wish to verify that it is fair and robust to deception. We are therefore interested in the problem of automatically verifying the game-theoretic properties of a given auction mechanism, especially the property of strategyproofness. In this paper we show how the Alloy model checker can be used to automatically verify such properties. We illustrate the approach via two examples: a simple two player Vickrey auction and a quantity restricted multi-unit auction using the Vickrey-Clarke-Groves mechanism.