A survey and taxonomy of consensus protocols for blockchains

【Author】 Singh, Arshdeep; Kumar, Gulshan; Saha, Rahul; Conti, Mauro; Alazab, Mamoun; Thomas, Reji

【Source】JOURNAL OF SYSTEMS ARCHITECTURE

【Abstract】Blockchain is an emerging decentralized and distributed technology. Along with the beneficial features of decentralization, transparency, and security the consensus algorithms of blockchains form key building blocks for this technology. Consensus protocol/algorithm helps to provide a decentralized decision making process. An efficient consensus algorithm is inclusive that engages all the participants to make their decision based on the conflicts of the blockchain networks. These consensus decisions lead to better quality outcomes of the blockchains and help to obtain the finality. Rigorous research is in process to upgrade or optimize the existing consensus protocols. The optimized or enhanced consensus protocols objectify to be suitable for Internet-of Thing (IoT) as the current versions of the protocols are not suitable for the resource-constrained environments due their complexity, hard configurations, mining techniques, high resource consumption, and explicit security loophole. In this paper, we present a survey of consensus protocols with a purpose to identify and discuss the existence of various consensus protocols available in literature. We emphasize on the genesis of the consensus protocols, particularly for Proof-of-X, byzantine fault tolerance, Paxos, and RAFT; we also include Directed Acyclic Graph (DAG) orientation of some contemporary algorithms. We discuss the variants of these genesis protocols. Our survey analyzes the advantages, disadvantages, and their applicability in IoTs. We enlist the categorical use of consensus algorithms in blockchains and other applications. Finally, we present several research trends and open issues emphasizing for consensus protocols emphasizing on IoTs. Compared to the other surveys in the field, our present survey objectifies to provide a more thorough summary of the most relevant protocols and application issues; this survey helps the researchers and the application developers to obtain an insight on the current status of the consensus protocols' suitability to deliver the desired functionalities in IoTs. The notified disadvantages of each of the protocol provide future scope for the industries and academia. To the best of our knowledge, such a comprehensive and summarized survey of consensus protocols including DAG-based protocols is unavailable in the literature and thus, our contribution claims are significant.

【Keywords】Consensus; Blockchain; Bitcoin; Protocol; Decentralization

【标题】区块链共识协议的调查和分类

【摘要】区块链是一种新兴的去中心化和分布式技术。除了去中心化、透明性和安全性的有益特性外，区块链的共识算法构成了该技术的关键构建块。共识协议/算法有助于提供去中心化的决策过程。一种高效的共识算法是包容性的，它让所有参与者根据区块链网络的冲突做出决定。这些共识决定导致区块链的质量更好，并有助于获得最终确定性。正在进行严格的研究以升级或优化现有的共识协议。优化或增强的共识协议客观地适用于物联网 (IoT)，因为当前版本的协议不适合资源受限的环境，因为它们的复杂性、硬配置、挖掘技术、高资源消耗和显式安全漏洞。在本文中，我们对共识协议进行了调查，目的是识别和讨论文献中可用的各种共识协议的存在。我们强调共识协议的起源，特别是 Proof-of-X、拜占庭容错、Paxos 和 RAFT；我们还包括一些当代算法的有向无环图（DAG）方向。我们讨论了这些创世协议的变体。我们的调查分析了物联网的优势、劣势及其适用性。我们争取在区块链和其他应用程序中分类使用共识算法。最后，我们提出了一些研究趋势和开放性问题，强调了强调物联网的共识协议。与该领域的其他调查相比，我们目前的调查客观地提供了对最相关的协议和应用问题的更全面的总结；该调查有助于研究人员和应用程序开发人员深入了解共识协议在物联网中提供所需功能的适用性的当前状态。每个协议的通知缺点为行业和学术界提供了未来的范围。据我们所知，文献中没有对包括基于 DAG 的协议在内的共识协议进行如此全面和总结的调查，因此，我们的贡献声明意义重大。

【关键词】共识;区块链；比特币；协议;权力下放

【发表时间】2022

【收录时间】2022-08-23

【文献类型】Article

【论文大主题】共识机制

【论文小主题】共识机制的比较和分析

【影响因子】5.836