The blockchain consensus protocols create an irrefutable system of agreement between the different parties within a distributed network, while preventing the harmful exploitation of the system. Let’s find out how these protocols work and how they differ from one system to another.
Definition of a consensus protocol
Blockchain consensus protocols ensure synchronization between all network nodes. Each consent aims to answer a specific question: how can we guarantee the authenticity of each transaction? Any individual can submit information and decide to store it on a blockchain. It is therefore essential to be able to review this information and decide by consensus whether or not it can be added to the network.
The term “consensus” means that all nodes in the network must agree on an identical version of the blockchain. Somewhere the mechanism of consensus of a blockchain it is an internal and automatic audit of its network. This protocol is therefore essential and has two functions:
- It allows you to update the blockchain while ensuring this each the chain lock is valid. People who participate in block validation (referred to as “nodes”) of the network must have an incentive to engage in network security, which usually takes the form of a monetary reward.
- They it only prevents one and the same entity can control the entire network and thus guarantees its decentralization.
The rules of a consensus protocol
A blockchain consensus follows specific rules. Network nodes guarantee this every block and every transaction meets a number of criteria before it can be validated. Each data must receive the unanimous acceptance of all the nodes of the network to be validated.
The main goal of consensus protocols is to be able to fight attacks that jeopardize the security of the network. A very common example of an attack is that of double spending or double spending. It consists of issuing two transactions that spend the same credit. The role of consent is therefore to decide which of its two operations can be considered validated and which one must be canceled.
The main blockchain consensus mechanisms
The consensus of a blockchain is defined by its creation by its founders. The most famous and the first of these is the proof of work (Proof-of-Work in English), which uses the Bitcoin protocol.
Proof-of-Work (PoW), or proof of work
The Proof-of-Work protocol is the most widely used of all blockchain consents. Since 2009 it has been able to demonstrate its resistance and safety to various attack attempts.
In the Proof-of-Work protocol the different network nodes are called minors. To confirm a transaction, miners must solve a complex mathematical problem that requires significant computing power.
To do this, they use a mathematical process called the hash function. Hashing is used to write transaction data in chunks and link them together. There are several types, such as SHA 256, used on Bitcoin. Once the hash registered in the blockchain, it is tamper-proof.
A miner is rewarded for every block he manages to approve and confirm. His income is proportional to the computing power he is able to use to solve the problem.
To learn more about the topic, we invite you to read our detailed definition of the protocol Proof of work.
Proof-of-Stake (PoS) or Proof-of-Stake
Proof-of-Stake, or Proof of Stake, is based on a completely different logic from Proof of Work and does not require any particular computing power. In Proof-of-Stake, consensus participants can be compared to shareholders of a business entity who have the privilege of participating in its consent mechanism.
PoS is a much less expensive consensus than PoW, because it requires neither energy expenditure nor special hardware. Specifically, to validate a block, the nodes must be here demonstrate possession of a certain amount of cryptocurrencyand pledge on the network. The greater this quantity, the more likely a node is chosen to update the ledger of a blockchain. The PoS consensus believes these people are more likely to want to fight a network attack, which could completely ruin them.
Find more details on the Proof-of-Stake by reading our article dedicated to the question.
Proof of delegated participation (DPoS) or proof of delegated participation
Emerging more recently, delegated Proof-of-Stake tends to address the weaknesses of PoS and PoW by offering a hybrid model.
DPoS Consent works on the same basic principle as PoS. However, the people in charge of forging blocks have to be elected by community members. The election system ensures that the blockchain is not controlled by a minority of people, as could be the case with a miner with a lot of computing power, or a PoS forger with a very large amount of tokens.
Smooth is a great example of a DPoS protocol. Its blockchain provides for the election of 101 delegates responsible for the consensus mechanism. These delegates are elected by the holders of lisk tokens and must return a portion of their winnings to the voters.
The DPoS protocol has many advantages, but also some disadvantages. To find out more, we invite you to read our article dedicated to the explanation of the Proof of delegated participation.
Proof of Work, Proof of Stake and Delegated Proof of Stake are the main blockchain consensus. There are many others.
Among the interesting consents, the Proof of importance of the Nem blockchain. Each node has an importance score. Its importance score determines how often it can spoof XEM. The importance of a node depends on how long it has had the tokens, but also on its contribution to the network: the more a node sends transactions to other users and uses the network, the more important it becomes. An interesting logic for create a lively and dynamic blockchain.