BLOCKCHAIN SYSTEM CONSENSUS ALGORITHMS

This article describes the main consensus algorithms, their positive and negative aspects. Consensus in the general sense means a way to come to an agreement. In the blockchain, which is a decentralized system that does not have a single governing body, various algorithms have been developed to achieve consensus. In a blockchain network, it does not matter whether the system participants trust each other or not. They must agree on certain principles of work that will apply to everyone. And this is a direct function of the consensus mechanism. Algorithms are described and an example of solving this problem is given, namely the problem of choosing a consensus for future systems. An example of using multiple consensuses in blockchain networks is given. Such consensuses as Proof of Work (PoW), proof of Capacity (PoC), proof of Authority (PoA), proof of activity (PoAA), proof of Importance (PoI), proof of Burn (PoB), proof of Stake (PoS) are described, as well as its subspecies: Leased Proof-of-Stake (LPoS), Delegated Proof-of-Stake (DPoS). Many different nuances about the mixed type of consensus are described and examples of such cryptocurrencies and systems are given. The subtleties of mining for each consensus are described. Examples of hash functions, masternodes, nodes, algorithms, as well as key features of certain cryptocurrencies with mixed consensus are given. It is concluded that the choice of consensus for building systems based on blockchain.