ABSTRACT
Cryptocurrencies created a trendsetter after the emergence of Bitcoin in the last decade. Blockchain technology is the backbone behind cryptocurrencies and gave rise to its usage in multidisciplinary fields. The future of payment with cryptocurrencies might lead to the end of manual cash. Blockchain features such as encryption, peer to peer (P2P), transparency, and timestamp make an immutable ledger to overcome the problem of a centralized system with a decentralized and trustworthy approach. Consensus algorithms are an essential component responsible for the secure flow of the network on the distributed ledger. The security and poor performance of consensus algorithms can cause hindrance for a wide range of adoption of blockchain. Drawbacks of blockchain can be addressed with a better understanding of how each consensus algorithm functions. There are various consensus algorithms according to different types of blockchains. Selection of the most appropriate consensus algorithm will improve the network performance and provide better outcomes. The analysis of varying consensus algorithms about specific metrics has been discussed. In this chapter, we will go through an 310introduction to blockchain, the emergence of cryptocurrencies, related work done in this field, the role of consensus algorithms, comparative analysis of existing consensus algorithms, limitations of each consensus algorithm, conclusion, and future scope.
