Transaction fee mechanism design is a new decentralized mechanism design problem where users bid for space on the blockchain. Several recent works showed that the transaction fee mechanism design fundamentally departs from classical mechanism design. They then systematically explored the mathematical landscape of this new decentralized mechanism design problem in two settings: in the plain setting where no cryptography is employed, and in a cryptography-assisted setting where the rules of the mechanism are enforced by a multi-party computation protocol. Unfortunately, in both settings, prior works showed that if we want the mechanism to incentivize honest behavior for both users as well as miners (possibly colluding with users), then the miner revenue has to be zero. Although adopting a relaxed, approximate notion of incentive compatibility gets around this zero miner-revenue limitation, the scaling of the miner revenue is nonetheless poor. In this paper, we show that if we make a mildly stronger reasonable-world assumption than prior works, we can circumvent the known limitations on miner revenue, and design auctions that generate optimal miner revenue. We also systematically explore the mathematical landscape of transaction fee mechanism design under the new reasonable-world and demonstrate how such assumptions can alter the feasibility and infeasibility landscape.

翻译：交易费用机制设计是一种新型去中心化机制设计问题，用户通过竞标争夺区块链上的记账空间。近期多项研究表明，交易费用机制设计从根本上区别于经典机制设计。研究者系统探索了这一新型去中心化机制设计问题在两种场景下的数学框架：未采用密码学保护的朴素场景，以及通过安全多方计算协议强制执行机制规则的密码学辅助场景。遗憾的是，在这两种场景下，既有研究证明：若要求该机制能激励用户和矿工（可能相互合谋）均保持诚实行为，矿工收益必须为零。即便采用激励相容的松弛近似概念能突破零收益限制，矿工收益的规模仍不理想。本文证明，若采用比既有研究稍强的理性世界假设，即可规避现有矿工收益限制，设计出能产生最优矿工收益的拍卖机制。我们系统探索了新理性世界假设下交易费用机制设计的数学框架，揭示此类假设如何改变机制可行性与不可行性的数学图景。