Sybil attacks, in which a large number of adversary-controlled nodes join a network, are a concern for many peer-to-peer database systems, necessitating expensive countermeasures such as proof-of-work. However, there is a category of database applications that are, by design, immune to Sybil attacks because they can tolerate arbitrary numbers of Byzantine-faulty nodes. In this paper, we characterize this category of applications using a consistency model we call Byzantine Eventual Consistency (BEC). We introduce an algorithm that guarantees BEC based on Byzantine causal broadcast, prove its correctness, and demonstrate near-optimal performance in a prototype implementation.

翻译：Sybil攻击使许多敌对者控制的节点加入一个网络,这是许多同侪数据库系统所关切的问题,因此必须采取诸如工作证明等昂贵的反措施。然而,有一类数据库应用程序,由于能够容忍任意数目的Byzantine-Faulty节点,因此在设计上不受Sybil攻击的影响。在本文中,我们使用我们称之为Byzantine 事件一致(BEC)的一致模式来描述这类应用。我们采用了一种算法,保证BEC以Byzantine因果广播为基础进行Byzantine因果广播,证明其正确性,并在原型执行中展示接近最佳的性能。