False-name-Proof Combinatorial Auction Mechanisms

In Internet auctions, it is easy for a bidder to submit multiple bids under multiple identifiers (e.g., multiple e-mail addresses). If only one good is sold, a bidder cannot make any additional profit by using multiple bids. However, in combinatorial auctions, where multiple goods are sold simultaneously, submitting multiple bids under fictitious names can be profitable. A bid made under a fictitious name is called a {em false-name bid}. In this talk, I describe the summary of existing works and open problems on false-name bids

Economic Mechanism Design for Securing Online Auctions

Enhancing e-commerce security through computing technology alone is not sufficient. E-commerce designers should apply economic mechanisms to design proper digital processes that accommodate new perspectives raised in e-commerce. For instance, traditional auction mechanisms, such as the Generalized Vickrey Auction, are vulnerable to false-name bidding, an online fraud exploiting the lack of authentication over the Internet. We develop a Sealed-bid Multi-round Auction Protocol (S-MAP), which sells multi-unit identical goods. S- MAP is not only robust against false-name bidding but also simple and efficient

Limited Verification of Identities to Induce False-Name-Proofness

In open, anonymous environments such as the Internet, mechanism design is complicated by the fact that a single agent can participate in the mechanism under multiple identifiers. One way to address this is to design false-name-proof mechanisms, which choose the outcome in such a way that agents have no incentive to use more than one identifier. Unfortunately, there are inherent limitations on what can be achieved with false-name-proof mechanisms, and at least in some cases, these limitations are crippling. An alternative approach is to verify the identities of all agents. This imposes significant overhead and removes any benefits from anonymity. In this paper, we propose a middle ground. Based on the reported preferences, we check, for various subsets of the reports, whether the reports in the subset were all submitted by different agents. If they were not, then we discard some of them. We characterize when such a limited verification protocol induces false-name-proofness for a mechanism, that is, when the combination of the mechanism and the verification protocol gives the agents no incentive to use multiple identi- fiers. This characterization leads to various optimization problems for minimizing verification effort. We study how to solve these problems. Throughout, we use combinatorial auctions (using the Clarke mechanism) and majority voting as examples

05011 Abstracts Collection -- Computing and Markets

From 03.01.05 to 07.01.05, the Dagstuhl Seminar 05011``Computing and Markets\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

Towards Optimal Prior-Free Permissionless Rebate Mechanisms, with applications to Automated Market Makers & Combinatorial Orderflow Auctions

Maximal Extractable Value (MEV) has become a critical issue for blockchain ecosystems, as it enables validators or block proposers to extract value by ordering, including or censoring users' transactions. This paper aims to present a formal approach for determining the appropriate compensation for users whose transactions are executed in bundles, as opposed to individually. We explore the impact of MEV on users, discuss the Shapley value as a solution for fair compensation, and delve into the mechanisms of MEV rebates and auctions as a means to undermine the power of the block producer

False-name-proof combinatorial auction design via single-minded decomposition

This paper proposes a new approach to building false-name-proof (FNP) combinatorial auctions from those that are FNP only with single-minded bidders, each of whom requires only one particular bundle. Under this approach, a general bidder is decomposed into a set of single-minded bidders, and after the decomposition the price and the allocation are determined by the FNP auctions for single-minded bidders. We first show that the auctions we get with the single-minded decomposition are FNP if those for single-minded bidders satisfy a condition called PIA. We then show that another condition, weaker than PIA, is necessary for the decomposition to build FNP auctions. To close the gap between the two conditions, we have found another sufficient condition weaker than PIA for the decomposition to produce strategy-proof mechanisms. Furthermore, we demonstrate that once we have PIA, the mechanisms created by the decomposition actually satisfy a stronger version of false-name-proofness, called false-name-proofness with withdrawal

Auctions and bidding: A guide for computer scientists

There is a veritable menagerie of auctions-single-dimensional, multi-dimensional, single-sided, double-sided, first-price, second-price, English, Dutch, Japanese, sealed-bid-and these have been extensively discussed and analyzed in the economics literature. The main purpose of this article is to survey this literature from a computer science perspective, primarily from the viewpoint of computer scientists who are interested in learning about auction theory, and to provide pointers into the economics literature for those who want a deeper technical understanding. In addition, since auctions are an increasingly important topic in computer science, we also look at work on auctions from the computer science literature. Overall, our aim is to identifying what both these bodies of work these tell us about creating electronic auctions. © 2011 ACM.This work was funded in part by HP under the “Always on” grant, by NSF IIS-0329037 “Tools and Techniques for Automated Mechanism Design”, and by IEA (TIN2006-15662-C02-01), OK (IST-4-027253-STP), eREP(EC-FP6-CIT5-28575) and Agreement Technologies (CONSOLIDER CSD2007-0022, INGENIO 2010).Peer Reviewe