This work aims to address the general order manipulation issue in blockchain-based decentralized exchanges (DEX) by exploring the benefits of employing differentially order-fair atomic broadcast (of-ABC) mechanisms for transaction ordering and frequent batch auction (FBA) for execution. In the suggested of-ABC approach, transactions submitted to a sufficient number of blockchain validators are ordered before or along with later transactions. FBA then executes transactions with a uniform price double auction that prioritizes price instead of transaction order within the same committed batch. To demonstrate the effectiveness of our order-but-not-execute-in-order design, we compare the welfare loss and liquidity provision in DEX under FBA and its continuous counterpart, Central Limit Order Book (CLOB). Assuming that the exchange is realized over an of-ABC protocol, we find that FBA achieves better social welfare compared to CLOB when (1) public information affecting the fundamental value of an asset is revealed more frequently than private information, or (2) the block generation interval is sufficiently large, or (3) the priority fees attached to submitted transactions are small compared to the asset price changes. Further, our findings also indicate that (4) liquidity provision is better under FBA when the market is not thin, meaning that a higher number of transactions are submitted by investors and traders in a block, or (5) when fewer privately informed traders are present. Overall, in the settings mentioned above, the adoption of FBA and of-ABC mechanisms in DEX demonstrates improved performance in terms of social welfare and liquidity provision compared to the continuous CLOB model.

翻译：本文旨在通过探索采用差分有序公平原子广播（of-ABC）机制进行交易排序，以及频繁批量拍卖（FBA）进行执行的优势，来解决基于区块链的去中心化交易所（DEX）中的通用顺序操纵问题。在所提出的of-ABC方法中，提交给足够数量区块链验证者的交易会在后续交易之前或与之同时进行排序。随后，FBA通过统一价格的双向拍卖执行交易，该拍卖在相同提交批次内优先考虑价格而非交易顺序。为了证明我们的"有序而非按序执行"设计的有效性，我们比较了DEX在FBA及其连续对应模型——中央限价订单簿（CLOB）下的福利损失和流动性供给。假设交易所通过of-ABC协议实现，我们发现当满足以下条件时，FBA相比CLOB能实现更好的社会福利：（1）影响资产基础价值的公共信息比私人信息更频繁地披露；（2）区块生成间隔足够大；（3）提交交易附加的优先费用相对于资产价格变化较小。此外，我们的研究还表明：（4）当市场并非稀薄（即单区块中投资者和交易者提交的交易数量较高）时，FBA下的流动性供给更优；或（5）当知情交易的投资者较少时。总体而言，在上述场景中，DEX采用FBA和of-ABC机制相比连续CLOB模型在社会福利和流动性供给方面表现出更优性能。