论文标题
温迪，好的小公平小部件
Wendy, the Good Little Fairness Widget
论文作者
论文摘要
分散交易市场的出现为共识协议带来了许多新的挑战。除了“常规”攻击（试图防止分歧的验证者）的子集之外，现在还有可能造成财务欺诈的可能性，财务欺诈可能滥用通常在共识协议中不关键的物业。我们调查了攻击者操纵或利用计划在区块链中安排交易的顺序的问题。更具体地说，我们研究相对顺序公平，即我们可以确保交易的相对顺序是公平的。我们表明，公平性最直观的定义之一是无法实现的。然后，我们提出Wendy，这是一组低架空协议，可以实现不同的公平概念。温迪是现有区块链的额外小部件，对基础区块链及其安全性假设不可知。此外，只能将协议仅应用于交易的一个子集，从而在同一链上运行几个独立的公平市场。
The advent of decentralized trading markets introduces a number of new challenges for consensus protocols. In addition to the `usual' attacks -- a subset of the validators trying to prevent disagreement -- there is now the possibility of financial fraud, which can abuse properties not normally considered critical in consensus protocols. We investigate the issues of attackers manipulating or exploiting the order in which transactions are scheduled in the blockchain. More concretely, we look into relative order fairness, i.e., ways we can assure that the relative order of transactions is fair. We show that one of the more intuitive definitions of fairness is impossible to achieve. We then present Wendy, a group of low overhead protocols that can implement different concepts of fairness. Wendy acts as an additional widget for an existing blockchain, and is largely agnostic to the underlying blockchain and its security assumptions. Furthermore, it is possible to apply a the protocol only for a subset of the transactions, and thus run several independent fair markets on the same chain.
