Blockchain is a distributed ledger that is decentralized, immutable, and transparent, which maintains a continuously growing list of transaction records ordered into blocks. As the core of blockchain, the consensus algorithm is an agreement to validate the correctness of blockchain transactions. For example, Bitcoin is a public blockchain where each node in Bitcoin uses the Proof of Work (PoW) algorithm to reach a consensus by competing to solve a puzzle. Unlike a public blockchain, a consortium blockchain is an enterprise-level blockchain that does not contend with the issues of creating a resource-saving global consensus protocol. This paper highilights several state-of-the art solutions in consensus algorithms for enterprise blockchain. For example, the HyperLedger by Linux Foundation includes implementing Practical Byzantine Fault Tolerance (PBFT) as the consensus algorithm. PBFT can tolerate a range of malicious nodes and reach consensus with quadratic complexity. Another consensus algorithm, HotStuff, implemented by Facebook Libra project, has achieved linear complexity of the authenticator. This paper presents the operational mechanisms of these and other consensus protocols, and analyzes and compares their advantages and drawbacks.

中文翻译：

---

财团区块链共识机制研究

区块链是一种分散的，不可变的，透明的分布式账本，维护着按顺序排列成块的交易记录的列表。作为区块链的核心，共识算法是一种验证区块链交易正确性的协议。例如，比特币是一个公共区块链，其中比特币中的每个节点都使用工作量证明（PoW）算法通过竞争解决难题来达成共识。与公共区块链不同，财团区块链是企业级区块链，不涉及创建节省资源的全球共识协议的问题。本文重点介绍了企业区块链共识算法中的几种最新解决方案。例如，Linux Foundation的HyperLedger包括实现实用的拜占庭容错（PBFT）作为共识算法。PBFT可以容忍一系列恶意节点并以二次复杂度达成共识。Facebook Libra项目实施的另一种共识算法HotStuff已实现了身份验证器的线性复杂性。本文介绍了这些协议和其他共识协议的运行机制，并分析和比较了它们的优缺点。