Survey of consensus protocols on blockchain applications

Blockchain is a distributed, transparent, immutable ledger. Consensus protocol forms the core of blockchain. They decide how a blockchain works. With the advent of new possibilities in blockchain technology, researchers are keen to find a well-optimized Byzantine fault tolerant consensus protocol. Creating a global consensus protocol or tailoring a cross-platform plug and play software application for implementation of various consensus protocols are ideas of huge interest. Stellar Consensus Protocol (SCP) is considered to be a global consensus protocol and promises to be Byzantine Fault Tolerant (BFT) by bringing with it the concept of quorum slices and federated byzantine fault tolerance. This consensus's working and its comparison with other protocols that were earlier proposed are analyzed here. Also, hyperledger an open-source project by Linux Foundation which includes implementing the concept of practical byzantine fault tolerance and also a platform where various other consensus protocols and blockchain applications can be deployed in a plug and play manner is also being discussed here. This paper focuses on analyzing these consensus protocols already proposed and their feasibility and efficiency in meeting the characteristics they propose to provide.