Review of Existing Consensus Algorithms Blockchain

In recent years, blockchain technology has begun to attract close attention. The blockchain solved the problem of replacing the original centralized ledger with a low level of trust, on a decentralized form with a high level of trust, which has various objects, or, in other words, checking nodes. The main feature of the blockchain technology is a consistent algorithm that decides how an agreement is reached on adding a new block between all nodes in the checking network. Blockchain algorithms can be divided into two main groups. There is consensus based on evidence. This group requires that nodes connecting to the inspection network show that they are more qualified than others to do the extra work. The second type is consensus, which is based on voting and requires that the nodes in the network exchange the results of the verification of a new block or transaction before making a final decision. This article provides an overview of existing blockchain consensus algorithms.