发表机构
University of Virginia（弗吉尼亚大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出MPC分解原则，将胜者确定隔离为最小MPC小工具以限制信息泄露，结合顺序揭示和有限惩罚设计顺序揭示拍卖，解决了可靠拍卖中免费期权问题，实现常数轮、激励兼容且收益最优的可靠拍卖。
AI 中文摘要
可靠拍卖（credible auctions）——即追求收益最大化的拍卖者没有动机偏离协议的一种机制——的设计，在拍卖者控制着托儿（shill）投标人的情况下，面临着一个根本性的密码学障碍。虽然一种自然的方法是使用安全多方计算（MPC）来移除受信任的拍卖者，但Cleve（1986）关于公平抛硬币的不可能性结果意味着，整体式MPC协议赋予了拍卖者一个“免费期权”：他们可以得知拍卖结果，并在收益不理想时单方面中断（abort）。具有事前惩罚的密码学承诺缓解了这种中断不对称性，但对于重尾分布，没有任何有限的惩罚是足够的。我们通过引入MPC分解原则（MPC Decomposition Principle）来绕过这一障碍。我们不是加密整个机制，而是严格地将MPC用作一种信息限制工具。我们将胜者确定问题隔离到一个最小的MPC小工具中，该小工具计算并揭示胜者的身份，但不揭示任何支付信息。这种定性限制在数学上界定了中断时泄露的信息量。通过将该小工具与顺序揭示（sequential revelation）和有限经济惩罚相结合，我们设计了顺序揭示拍卖（Sequential Revelation Auction, SRA）。我们证明了界定信息泄露严格地界定了免费期权的价值，表明惩罚k ≥ ∑_{i=1}^n Rev(F_i)足以保证可靠性，并且这个界限是紧的：对于等收益分布，任何更小的惩罚都会允许有利可图的偏离。使用常数轮MPC，SRA解决了Akbarpour和Li（2020）以及Ferreira和Weinberg（2020）的一个开放性问题，为所有具有消失收益尾部的产品分布提供了一个常数轮、激励兼容、收益最优的可靠拍卖。
英文摘要
The design of credible auctions---mechanisms where a revenue-maximizing auctioneer has no incentive to deviate from the protocol---faces a fundamental cryptographic barrier when the auctioneer controls shill bidders. While a natural approach is to use Secure Multi-Party Computation (MPC) to remove the trusted auctioneer, the impossibility of fair coin flipping of Cleve (1986) implies that monolithic MPC protocols grant the auctioneer a "free option": they can learn the auction's outcome and unilaterally abort if the revenue is unsatisfactory. Cryptographic commitments with ex-ante penalties mitigate this abort asymmetry, but no finite penalty suffices for heavy-tailed distributions. We circumvent this barrier by introducing the MPC Decomposition Principle. Rather than encrypting the entire mechanism, we use MPC strictly as an information-restriction tool. We isolate the winner determination problem into a minimal MPC gadget that computes and reveals the winner's identity but no payment information. This qualitative restriction mathematically bounds the information leaked upon an abort. By combining this gadget with sequential revelation and finite economic penalties, we design the Sequential Revelation Auction (SRA). We prove that bounding the information leakage strictly bounds the value of the free option, showing that a penalty of $k \geq \sum_{i=1}^n Rev(F_i)$ is sufficient for credibility, and tight: for equal-revenue distributions, every smaller penalty admits a profitable deviation. Using constant-round MPC, the SRA resolves an open question of Akbarpour and Li (2020) and Ferreira and Weinberg (2020) by providing a constant-round, incentive-compatible, revenue-optimal credible auction for all product distributions with vanishing revenue tails
Comments32 pages, AFT 2026
