Consensus Mechanisms in Blockchain
Tags: blockchain, web3, beginners, learning
Published: 2022-08-30 09:20:32

Image credit: crypto.com

Firstly, what are consensus mechanisms?

Consensus mechanisms are the process by which a blockchain network agrees on the validity of transactions. In order for a transaction to be added to the blockchain, it must be approved by all nodes in the network

A **node** in the blockchain is a computer that connects to the blockchain network and helps verify and relay transactions. Nodes are important because they help keep the blockchain secure by verifying transactions.

In order to be a part of the network, nodes must agree on a set of rules, or protocol, for how transactions are verified.

**Why Blockchains need Consensus Mechanisms?**


**Types Of Consensus Mechanisms**

**1. Proof of work - PoW**
Proof of work is a requirement that is put in place to ensure that blockchains are secure. In order for a new block to be added to the blockchain, the miner must solve a difficult mathematical problem.

In order to create a new block, miners must solve a difficult cryptographic puzzle. The first to come with the 64-digit hexadecimal number (has) gets the right to form the new block. The winner is also given a speculated block reward.

This proof of work requires significant computational resources, so it can't be faked or duplicated. The proof of work also verifies the legitimacy of transactions, preventing fraud and double spending.

**2.Proof of stake - PoS**

Proof of stake is a type of algorithm used by blockchain networks to confirm transactions and create new blocks. In proof of stake, the creator of the next block is chosen based on their ownership stake in the network.

This means that people who own more tokens will have a greater chance of creating a new block and earning rewards. Proof of stake is seen as more efficient and secure than other methods such as proof of work because it doesn't require miners to use large amounts of electricity.

**3. Delegated proof of stake - (DPoS)**

Delegated proof of stake (DPoS) is a blockchain consensus algorithm that allows stakeholders to vote for delegates, who are responsible for validating transactions and maintaining the blockchain.

Delegates can be voted out if they do not perform their duties properly. DPoS is considered more efficient and scalable than other consensus algorithms, such as proof of work or proof of stake.
**5. Proof of activity (PoA)**
Proof of activity (PoA) is a consensus algorithm that uses both proof of work and proof of stake. PoA is designed to be more efficient than pure proof of work or pure proof of stake systems.

In a PoA system, blocks are created by miners who are able to prove that they have done some work. Miners can also prove that they own some coins, which allows them to vote on the validity of blocks. Blocks are accepted if most voters agree that they are valid.

PoA is less secure than other consensus algorithms, but it is faster and more efficient.

**5. Proof of authority (PoA)**

Proof of authority (PoA) is a consensus algorithm that enables participants to reach an agreement on the state of a blockchain. PoA relies on pre-approved nodes known as authorities, which are responsible for validating transactions and blocks.

This makes it less computationally intensive than other algorithms and allows for faster transaction times.

**6. Proof of burn (PoB)**

Proof of burn is a way to secure the blockchain and prevent attacks. It works by requiring users to "burn" or destroy some of their coins in order to create a new block.

This makes it more difficult for someone to attack the blockchain, as they would need to have enough coins to cover both the cost of creating a new block and burning them. Proof of burn is also used as a way to distribute new coins, as those who burned the most coins are rewarded

**7. Proof of capacity/proof of space (PoC/PoSpace)**

Proof of Capacity/Proof of Space is a way to allocate resources in a Blockchain. It is used to determine who can participate in the network and how much storage they are allowed to use.

Proof of Capacity/Proof of Space uses the amount of disk space that you have available as your proof. This allows people with more disk space to be rewarded for their contribution.

The file must be submitted in advance and can be verified by other miners. If the miner does not have enough available storage space, their submission will be rejected.

This ensures that blocks are only added to the blockchain if there is sufficient storage capacity available, which helps prevent overcrowding and slows down the growth rate of blockchain data files. It also prevents malicious actors from adding illegitimate blocks to the chain.

**7. Proof of elapsed time (PoE)**

Proof of elapsed time (PoET) is a consensus algorithm used in blockchain technology that helps to prevent spam attacks and ensure the fairness of the network.

It works by requiring participants to solve a cryptographic puzzle, with the solution being verified by other participants. The amount of time it takes to solve the puzzle is used as a measure of how trustworthy the participant is.

PoET can be used in conjunction with other algorithms, such as proof-of-work or proof-of-stake, to provide additional security and reliability. It is more efficient than other methods when it comes to preventing spam attacks, and it can also help reduce energy consumption.

**8. Proof of History (PoH)**
Proof of History is a new way to verify the authenticity of digital documents and data. It operates by embedding hashes of documents into the blockchain, allowing anyone to verify that a document has not been altered since it was added to the blockchain

PoH also allows you to track changes made to a document over time, so you can see who made which changes and when. This makes it an ideal solution for verifying the integrity of data or documents in cases where fraud or tampering is suspected.

9.**Proof of Importance (PoI)**

Proof of Importance (PoI) is a consensus algorithm used by some blockchain networks, such as Nxt and BitShares.

PoI is based on the idea that not all nodes in a network are equal, and that some nodes should have more say in the network than others. Nodes with more importance are called "witnesses".

Witnesses are chosen randomly, but those who have been active on the network for a long time or who hold more coins have a higher chance of being chosen. Witnesses are responsible for confirming transactions and adding them to the blockchain.

They also vote on changes to the network protocol. In order to be elected as a witness, you must submit your candidacy to one of the existing witnesses.