Table 1. Comparison of blockchain consensus mechanisms.
| Consensus | Year | Type | Mining | Scalability |
|---|---|---|---|---|
| Practical byzantine consensus algorithm | 1999 | Permissioned | Round of mining | Not scalable |
| PoW | 1999 | Permissionless | Yes | Low |
| PBFT | 1999 | Permissioned | No | Very high |
| Proof of work | 2008 | Permissionless | Computational power | Not scalable |
| Proof of stake | 2011 | Permissioned and permissionless | Node wealth and staking age | Scalable |
| Ripple | 2012 | Permissioned | No | High |
| PoS | 2012 | Permissionless | Yes | High |
| Raft | 2013 | Permissioned | No | Low |
| Proof of stake velocity | 2014 | Stake and amount (velocity) | Scalable | Low |
| DPoS | 2014 | Permissionless | Yes | Very high |
| Proof of burn | 2014 | Permissioned and permissionless | Coin burning (probabilistic lottery) | Scalable |
| Proof of activity | 2014 | Permissionless | Effectiveness of work by the miner | Scalable |
| Tendermint | 2014 | Permissioned | No | Very high |
| ELASTICO | 2016 | Permissionless | No | Low |
| Implicit consensus | 2017 | Permissioned | No | Not scalable |
| Proof of vote | 2017 | Consortium | Voting mining | Very low |
| DBFT consensus algorithm | 2018 | Permissioned | Random selection of miner | Not scalable |
| Proof of trust (PoT) | 2018 | Permission-based consortium | Probabilistic and voting mining | Scalable |
| LibraBFT | 2020 | Permissioned | Voting mining | Scalable |