Table A.1 shows the different types of consensus mechanism of blockchain, how it works briefly, and their characteristics regarding energy consumption and the level of decentralization.
Table A.1. Types of Consensus Mechanism of Blockchain
| Type | Explanation | Energy | Decentralized |
|---|---|---|---|
| Proof of Work | All participants compete to solve a time-consuming math puzzle. The winner is allowed to add the transactions to the block on the chain. | Very High | High |
| Proof of Stake | Participants stake monetary value, and the winner is selected by the amount of value they staked. After certain number of participants confirm the winner’s validation, block is added to the chain. | Low | High |
| Delegated Proof of Stake | Spin of PoS. A smaller number of delegates are selected in the network. They do publishing the block, and checking the work done by other delegates. | Low | Low |
| Proof of Authority | Spin of PoS. Instead of staking monetary value, participants stake actual identity. In this way people make their reputation at risk and are incentivized not to work maliciously. | Low | Middle |
| Proof of History | Spin of PoS. While timestamp function is used in PoS, verifiable delay function, which calculates the time by historical occurrences, is used in PoH. Not largely tested yet, and potentially vulnerable. | Low | High |
| Proof of Activity | Hybrid of PoW and PoS. Less data is included in the block header than PoW. Similar to PoS, group of nodes validate the new block. Rewards are split between miner and validating nodes. | Middle | High |
| Proof of Capacity | In the “plotting” stage, all possible solution is determined. Then in the “mining” stage, the shortest solution gets the right to mine the next block. | Low | High |
| Proof of Elapsed Time | Used on permissioned blockchain. The waiting time is randomly assigned to the participants. The first finished waiting gets to commit the next block on the chain. | Very Low | Very Low |
🔗 https://medium.com/the-daily-bit/9-types-of-consensus-mechanisms-that-you-didnt-know-about-49ec365179da
🔗 https://coinmarketcap.com/alexandria/glossary/proof-of-history-poh