Today we’ll take a look at a few of the most popular consensus models that are in play on different blockchain today. In a previous article, I explained that consensus is a way for key players (especially miners or nodes) in a blockchain to decide how a blockchain is going to behave in terms of speed of transactions, mode of confirmation of transactions, time of confirmation, etc.
Blockchain Consensus like The Senate
The Senate in a country’s Government can be used to adequately explain what a blockchain consensus is all about. This explanation is centered on a democratic system of Government using the British Government as an example.
Imagine a Senate without the Senate president or any central power body. Each senate is elected from a Senatorial District to represent people. Each senator is a node or computer scattered all over the world. Each bill passed into law can be seen as transactions, the time it took can be likened to the block times and the constitution can be seen as the blockchain ledger. The consensus algorithm in this example can be likened to the system of making laws as agreed on by the Senate.
Some of the most popular consensus algorithms are Proof of Work (PoW), Proof of Stake (PoS), Delegated Proof of Stake (DPoS), Proof of Authority (PoA), etc.
Proof of Work
Let’s say the senators in the illustration above make decisions based on the work capacity of each senator. You know Governments of countries distribute allocations unequally between territories but based on many criteria like landmass, rate of returns or internally generated revenues, etc. or we can say, basically based on the ‘works’. A senator will have more say in the Senate if he has the capacity to do more works for the country. Likewise, on a blockchain that operates based on the Proof of Work algorithm, transactions are confirmed when computers or nodes do a very complex calculation in a short period of time ahead of other nodes. This is done to secure the network from intruders. The winning node is rewarded with a block reward. This means that nodes or computers or miners operating on this kind of network must be powerful and very fast, thus, in most cases, they consume a lot of electrical power.
Some examples of blockchains working on the PoW model are Bitcoin, Ethereum, Digibyte, etc. Much research has shown that the PoW algorithm consumes a lot of power and might not be earth-friendly as it contributes to more greenhouse gas emission and ultimately global warming. But the good news is that some blockchains like Digibyte have been built to allow even less powerful miners to operate and mine to gain block rewards. This is called mining decentralization. It is all about giving everyone the same opportunity to be a node or mine coins.
Proof of Stake
Let’s say, according to our illustration, the senate makes decisions based on votes, and votes are counted based on stake. For example, each senator’s vote is not equal. Each senator’s vote is worth their stake or how much they have in the government. Blockchains based on PoS confirm transactions and reward block rewards based on the number of coins (stake) held by nodes or wallets all over the world. Wallets with more stakes are more likely to find blocks than other wallets.
The perceived school of thought behind the Proof of Stake algorithm is that it is less likely for you to allow the downfall of a cooperative society, for example, if you have so much to lose.
Examples of blockchains under this category are I/O coin, Xinfin, EDC blockchain (though, this one uses a leasing proof of Stake), etc.
There are so many innovative improvements on this kind of algorithm like Delegated Proof of Stake, Leasing Proof of Stake (as identified above), Proof of Authority, etc.
Delegated Proof of Stake, DPoS
In a democratic world, all things are decided with votes from citizens. Senators are elected as representatives in deciding important matters pertaining to the community. In a DPos algorithm, all coin holders are voters who can elect representatives or ‘witnesses’. These witnesses confirm transactions and make important decisions for the whole network.
Examples of blockchains operating on this kind of algorithm are STEEM Blockchain, Hive Blockchain, etc.
Proof of Authority (PoA)- A consensus with Authority
PoA algorithm operates just like DPoS only that PoA model operates more like an organizational structure where positions are delegated respectively to the members of the board. And the number of elected members is smaller than that of DPoS and members of the board rotates out and new ones are elected. The scenario under that of Proof of Authority should not be confused to the ‘organizational structure’ as compared above. Despite having board members, the Proof of Authority algorithm is not centralized and does not have a centralized head as known in the world. An example is Vechain.
Alright, it is enough right here, I really don’t intend for it to be this long. I hope you understand better about basic blockchain consensus. If you need more information about blockchain consensus, why not check this comprehensive article I wrote.
Thanks for reading.