区块链共识协议综述

Survey on Blockchain Consensus Protocol

共识协议作为区块链的核心技术,近年来已经得到学术界和产业界的广泛重视,并取得了一系列研究成果.当前,关于共识协议的综述研究一般将共识协议作为整体进行比较分析,缺乏对共识协议中主要步骤的解耦与比较.将共识协议分为出块节点选举和主链共识两个主要步骤,并针对每个步骤进行协议间的分析比较.在出块节点选举部分,主要讨论工作量证明和权益证明,分析其中存在的问题以及相应解决方案的分类比较.在主链共识部分,针对概率性共识和确定性共识,总结其安全目标,并进行安全性分析比较.通过对区块链共识协议的系统梳理,最后总结共识协议的发展现状和发展趋势,以及未来的重要研究方向.

As the core technology of blockchain, consensus protocol has received great attention from academy and industry in recent years, and made a series of research achievements. Existing surveys on consensus protocols generally regard the consensus protocol as a whole, and do not decouple and compare its main components. In this survey, the consensus protocol is divided into two main components, i.e., blocker election and main chain consensus, and their analysis and comparison are conducted correspondingly. In the blocker election component, two mechanisms are mainly discussed, i.e., proof of work and proof of stake. For each mechanism, the encountered problems are analyzed and their corresponding solutions are compared with each other. In the main chain consensus component, its security goal is summarized and security comparison is conducted for probabilistic consensus and deterministic consensus. Through the comprehensive review of the state-of-the-art consensus protocol in blockchain, the developing status, developing trend and some important research directions are finally summarized for the consensus protocol.