Consensus Protocol in Blockchainby@chixzyoge
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Consensus Protocol in Blockchain

by Chinaza OgechukwuJune 28th, 2022
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A consensus protocol in blockchain requires an agreement of a trusted node in the peer-to-peer network. Transactions that occur on the blockchain are reliable and all networks agree on a consensual algorithm of the blocks. The protocol controls all the activities of the network making blockchain a secured technology in cryptocurrency. All cryptocurrencies rely fully on the Proof-of-work and Proof of Stake consensus for their security and integrity. The voting system encouraged in this method of communication does not guarantee a trusted transaction. In recent times where __Cryptography interference with blockchain (

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In recent times where Cryptography interference with blockchain is inevitable, the blockchain consensus protocol designed from a decentralized network enables various nodes to communicate by validating data through a hashing algorithm to prevent a malicious attack such as double-spending. This consensus protocol is the backbone of the native cryptocurrency network.

A consensus protocol in blockchain, therefore, requires an agreement of a trusted node in the peer-to-peer network. Transactions that occur on the blockchain are reliable and all networks agree on a consensual algorithm of the blocks. The protocol controls all the activities of the network making blockchain a secured technology in cryptocurrency.

In the year 2008, a cryptocurrency software called Bitcoin was introduced by Satoshi Nakamoto where he explained the Proof-of-work as a consensus protocol, which involves the connection of a wide range of CPUs that are given a mathematical puzzle to solve. In which the longest chain of blocks communicates to other nodes quickly for validation thereby, creating a new block.

The solution proposed by Satoshi was a result of solving the Byzantine Generals’ problem. Formulated in 1982 where a group of generals is unable to communicate efficiently when an attack or retreat decision is made. The consensus among the general agreeing to attack or retreat was limited and this exposes them to fraudulent activities or disengaging communication amongst them. The voting system encouraged in this method of communication does not guarantee a trusted transaction.

In Blockchain technology ledgers are widely distributed through a decentralized medium of communication that must be secured to avoid disruption in the cryptocurrency ecosystem. All cryptocurrencies, however, rely fully on the Proof-of-work and Proof-of-stake consensus for their security and integrity.

Types of consensus protocol

Proof of Work (PoW)

This consensus protocol involves the use of hash functions in validating transactions from a set of nodes until a random number (nonce) of trailing zeros is generated and distributed effectively. This method of communication has proven to be the best in the system of cryptocurrency. For example Bitcoin and Litecoin

The data inputted through the hash function gives an output similar to the data created else if any changes are made, it automatically changes the whole hash. It is difficult for an attacker to break these hashes due to the stake of acquiring machines and electricity to run these hashes. A network needs to run these data created to verify if it is a trusted source or to detect any malicious act.

Miners take a long time to solve these mathematical puzzles, and the first person to solve the problem is rewarded with a native currency. It is however scalable as it quickens transaction validation processes and helps mining effective

Proof of Stake (PoS)

Blocks are not mined in this method of a consensus protocol, they rather validate data and proceed to form new blocks without spending time. Certain transaction fees are placed as a penalty for invalidation of transactions. This consensus algorithm does not require hash functions, higher energy-consuming power, or electricity in maintaining the public ledger as compared to the proof of work.

Part of the cryptocurrency is used to stake by the validators, the more the stake the higher the chances of proof of stake. Ethereum falls into this consensus category as it improves performance and reduces cost. Although this method is plausible it doesn't erase the issue of double-spending. There is no reward for native currency and can be issued as a distribution mechanism.

Proof of Capacity (PoC)

In Proof of Capacity, the mathematical puzzle solved in the proof-of-work is computed into hardware to help verify transactions. This hardware consumes disk space and miners are allocated blocks depending on the storage capacity. The faster the miners in computing solutions to the puzzle created the chances of forming new blocks.

The cryptocurrencies that depend on this consensus are Burstcoin and SpaceMint. This method of solving the mathematical problem is called Plots. They are embedded in the disk and are deciphered using an algorithm. Native currency is awarded to the miner who beats time while solving the problem and is also given storage hardware.

Proof of Elapsed Time (PoET)

The consensus protocol follows an efficient lottery system, which allows minimal use of resources and electrical consumption. Every validator is allowed to form its block and at that point, every node is hibernated for an amount of time before it can join the network to validate the winner through sending information to all networks.

Here the identity of the miner is synchronized before being allowed to access the network, thus it does not allow unknown networks. Equal chances are given to each participant in winning with two factors in this consensus, making it credible. This method of a consensus protocol, however, requires hardware and a third party for its implementation.

Proof of Burn (PoB)

This consensus mechanism allows miners to destroy the virtual crypto token to create blocks equal to the burn coin. The output of the coin generated is dependent on the coin burn. This is done using asymmetric cryptography where addresses are sent for validation from untraceable networks.

Resources are wasted irrespective of the mining processes. The cryptocurrency that uses this method of consensus is the Slim coin, which allows miners to commit to a long-term innovation, it also helps reduce coin circulation making it scarce.

Proof of Importance (PoI)

This consensus protocol involves the participation of Investors and validators for its operation. The amount invested and transactions made through a particular node facilitate the proof of importance.

This network base is difficult to attack due to the number of shareholders responsible for the security network.

Aims of the Consensus Protocol

Prevent double spending

The double-spending effect in the issue of one key cryptography is restricted due to the proof of work required for mining to take place. Keys are secured from addresses making it difficult for an attacker to acquire 51% of the mining stake.


Consensual agreement among the miners or validators on the longest block to form a new and pre-existing header through a unified hash function. Information conveyed is trusted and shared for a consensus to take place.

Reward Incentives

The consensual protocol aims at rewarding innovators for proof of work or proof of staking which are the most used protocols. The one who gains more native currency puts on more to get rewarded.

Equal Opportunity

For a consensus mechanism to be activated. Every node is given an equal opportunity to carry out proof of work in the ecosystem. This makes it justifiable and trustworthy in the decentralized network.


From the above readings, one can say that a consensus protocol in the blockchain system is a necessary tool in navigating transaction processes through the networks. Since there are no trusted third parties to validate these transactions, consensual methods are agreed upon by a group of people in the transferring of information from one node to the other.

In blockchain technology, the widely used consensus protocol is the proof-of-work and the proof-of-stake. Although both are not the ideal consensus mechanism, they are however feasible in the ecosystem. Consensus protocols are used in other scopes of enterprises, they are obtainable and secured to carry out different activities for transparency.