Order-Fairness for Byzantine Consensus
Order-Fairness for Byzantine Consensus
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DOI：
10.1007/978-3-030-56877-1_16
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发表时间：
2020-08
期刊：
影响因子：
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通讯作者：
Mahimna Kelkar;Fan Zhang;Steven Goldfeder;A. Juels
中科院分区：
文献类型：
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作者：
Mahimna Kelkar;Fan Zhang;Steven Goldfeder;A. Juels
几十年来，密码学和分布式系统的研究已经广泛地研究了状态机复制问题，也称为拜占庭共识。共识协议必须满足两个属性：一致性和活性。这些属性确保诚实的参与节点同意相同的日志，并规定何时添加新的事务。然而，它们无法确保日志中事务的实际顺序不被敌对操纵。事实上，在基于领导者的协议（几乎所有的协议今天使用），恶意领导者可以直接选择最终的交易顺序。为了纠正这个问题，我们提出了第三个共识属性：交易顺序公平。我们发起了第一次正式调查的秩序公平，并解释其根本的重要性。我们给出了几个自然的定义，分析了实现它们所需的假设，并提出了一类新的共识协议Aequitas。Aequitas协议是第一个在一致性和活性的基础上实现顺序公平的协议。它们可以使用现有的广播和协议原语（或实际上使用任何共识协议）以黑盒方式实现，并在同步和异步网络模型中工作。
Decades of research in both cryptography and distributed systems has extensively studied the problem of state machine replication, also known as Byzantine consensus. A consensus protocol must satisfy two properties:consistencyandliveness. These properties ensure that honest participating nodes agree on the same log and dictate when fresh transactions get added. They fail, however, to ensure against adversarial manipulation of the actualorderingof transactions in the log. Indeed, in leader-based protocols (almost all protocols used today), malicious leaders can directly choose the final transaction ordering.To rectify this problem, we propose a third consensus property:transaction order-fairness. We initiate the first formal investigation of order-fairness and explain its fundamental importance. We provide several natural definitions for order-fairness and analyze the assumptions necessary to realize them.We also propose a new class of consensus protocols called Aequitas. Aequitas protocols are the first to achieve order-fairness in addition to consistency and liveness. They can be realized in a black-box way using existing broadcast and agreement primitives (or indeed using any consensus protocol), and work in both synchronous and asynchronous network models.