Privacy-Enhancing Auctions Using Rational Cryptography
We consider enhancing with privacy concerns a large class of auctions, which include sealed-bid single-item auctions but also general multi-item multi-winner auctions, our assumption being that bidders primarily care about monetary payoff and secondarily worry about exposing information about their type to other players and learning information about other players’ types, that is, bidders are greedy then paranoid. To treat privacy explicitly within the game theoretic context, we put forward a novel hybrid utility model that considers both monetary and privacy components in players’ payoffs.
We show how to use rational cryptography to approximately implement any given ex interim individually strictly rational equilibrium of such an auction without a trusted mediator through a cryptographic protocol that uses only point-to-point authenticated channels between the players. By “ex interim individually strictly rational” we mean that, given its type and before making its move, each player has a strictly positive expected utility. By “approximately implement” we mean that, under cryptographic assumptions, running the protocol is a computational Nash equilibrium with a payoff profile negligibly close to the original equilibrium.
- 1.Abraham, I., Dolev, D., Gonen, R., Halpern, J.: Distributed computing meets game theory: robust mechanisms for rational secret sharing and multiparty computation. In: PODC 2006, pp. 53–62. ACM, New York (2006)Google Scholar
- 5.Escamocher, G., Miltersen, P.B., Santillan-Rodriguez, R.: Existence and computation of equilibria of first-price auctions with integral valuations and bids. In: AAMAS 2009 (2009)Google Scholar
- 6.Gordon, S.D., Hazay, C., Katz, J., Lindell, Y.: Complete fairness in secure two-party computation. In: STOC 2008, pp. 413–422. ACM, New York (2008)Google Scholar
- 8.Halpern, J., Pass, R.: Game theory with costly computation (manuscript) (2008)Google Scholar
- 9.Halpern, J., Teague, V.: Rational secret sharing and multiparty computation: extended abstract. In: STOC 2004, pp. 623–632. ACM, New York (2004)Google Scholar
- 10.Izmalkov, S., Lepinski, M., Micali, S.: Rational secure computation and ideal mechanism design. In: FOCS 2005, pp. 585–594. IEEE, Los Alamitos (2005)Google Scholar
- 12.Kol, G., Naor, M.: Games for exchanging information. In: STOC 2008, pp. 423–432. ACM, New York (2008)Google Scholar
- 13.Lepinksi, M., Micali, S., shelat, a.: Collusion-free protocols. In: STOC 2005, pp. 543–552. ACM, New York (2005)Google Scholar
- 14.Lepinski, M., Micali, S., Peikert, C., shelat, a.: Completely fair SFE and coalition-safe cheap talk. In: PODC 2004, pp. 1–10. ACM, New York (2004)Google Scholar
- 17.Micali, S., shelat, a.: Purely rational secret sharing (extended abstract). In: TCC 2009. LNCS, vol. 5444, pp. 54–71. Springer, Heidelberg (2009)Google Scholar
- 18.Naor, M., Pinkas, B., Sumner, R.: Privacy preserving auctions and mechanism design. In: 1st International Conference on Electronic Commerce, pp. 129–139. ACM, New York (1999)Google Scholar
- 20.Ong, S.J., Parkes, D., Rosen, A., Vadhan, S.: Fairness with an honest minority and a rational majority. In: TCC 2009. LNCS, vol. 5444, pp. 36–53. Springer, Heidelberg (2009)Google Scholar
- 21.Parkes, D.C., Rabin, M.O., Shieber, S.M., Thorpe, C.A.: Practical secrecy-preserving, verifiably correct and trustworthy auctions. In: 8th International Conference on Electronic Commerce, pp. 70–81. ACM, New York (2006)Google Scholar