An applied investigation of Consensus Algorithms Used in Blockchain Networks

Today, Blockchain technology is seen as a revolutionary technology in the business environment, and the peak of its prosperity was the introduction of Bitcoin in 2008. Blockchain networks allow centralized databases and general ledgers to be replaced, protected, and distributed databases to network members recognized as network verifiers. The most important part of the Blockchain network structure is the consensus algorithm, which determines how a new block between all nodes in the verifying network is agreed to be appended. In other words, consensus algorithms decide rules and protocols that define which block and by which member to connect to the main chain, and prevent parallel and conflicting structures. Consensus algorithms can be divided into two principal classes. The first category is proof-based consensus algorithms, which allow the nodes that enter the verifying network to demonstrate that they are more eligible and better than the others to do the new block that is to be added. The second group is consensus algorithms focused on voting, allowing nodes in the network to share their results from checking a transaction or a new block before making the final decision. In this paper, we discuss consensus algorithms that have been researched and are currently being applied in some well-known Blockchain applications, while discussing and comparing key features in various aspects.