Usable and Efficient Secure Multiparty Computation

The objective of this workpackage is twofold. On the one hand, it will investigate how we can use SMC to play games in strategic or extended form, how to implement mechanism design, and more generally how to execute protocols with selfish agents in the absence of a central trusted authority. In the opposite direction, it will investigate how to use game-theoretic assumptions to partially replace the stronger cryptographic assumptions in some MC applications with the hope of improving efficiency without significant weakening of the assumptions. The game-theoretic and the cryptographic assumptions share the notion of private information, but they differ on the way they value the information (leaked or extracted): game-theoretic assumptions, based on the notion of utility, implicitly place a finite value to the information while the stronger cryptographic assumptions consider this value essentially infinite. The two directions (using SMC for making game-theory practical and using game-theory for making SMC efficient) are tightly connected and it is natural to place them together in a single workpackage.