Bitcoin Forum

 What is consensus and for what it in general is necessary in a blockchain? As this technology means decentralization, it is logical that there is no single uniform control center which is responsible for making decisions. It is big plus on the one hand as excludes a possibility of corruption, but with another, all participants of system have to come to the uniform agreement, consensus without which the blockchain won't be able to function.


Therefore, a consensus can be defined as the decision that is taken by a group of persons in the interest of the whole is the achievement of solidarity by a certain community. Consensus, like in democracy, takes into account the opinion of the majority, not of the minority, but its goal is to maintain the stable operation of the entire system. And, all voices are equivalent and what them will be more, the decision will be more objectively as a result.


Proof of Work (PoW)

Used in: Bitcoin, Ethereum, Litecoin, Monero, ZCash, Dogecoin.

Miners solve cryptographic problems, calculating (mining) the next block, which will be added then to the blockchain. It demands big computing capacities, power expenses and everything is arranged in such a way that process constantly becomes complicated. As soon as the new block is found, it goes to network for verification. Then follows a simple process of block checking on identity.


This is a relatively effective type of consensus, but its main drawback is large energy consumption. Also, people and the companies which possess faster and powerful computers (ASIC) have more chances to find solutions and new blocks.

Proof of Stake (PoS)

Used in: VCash, BitBay, Peercoin, Qtum, Stratis.

This kind of consensus makes the entire mining process virtual and replaces the miners with special people, validators, that influence on decision-making. In PoS validators block some of their coins as bets. After that they begin check of blocks and as soon as there is a block which meets chain conditions they stake on it, thereby confirming the choice. If the block is added, then the validators are rewarded in proportion to their rates. Advantages of this consensus before the same PoW consists in smaller energy consumption, it is possible to work from any device online, but its minus - a large number of time-blocked funds, which makes mining more elitist.

This is like a system in blockchain which will take decision in a democratic way. With the ever increasing flow of the investors in the market of crypto currency, different types of coins are coming to this market and so the market has become very big and complex. But to create such consensus, participation from all is needed.

Thanks for the information's. I was searching for the meaning of POW. Now i know about it.

This type of consensus required the unanimous decision of all the people in the crypto currency market to be able to go effortlessly and smoothly. This is a part of the blockchain system and is needed given that the market has become quite critical and it needs order to be restored.   

Great article, particularly for newbies to the crypto industries. If anybody wants to go on for a little more light reading you might want to look at mixed consensus protocols, and other other ones like proof of authority and proof of online, which are some variants of the proof of work algorithms.

That's an interesting post. I like the idea of consensus. Through consensus, datas are collected regarding various topics and which might be beneficial in the future.

In the language of crypto currency, the achievement of solidarity by a certain community is called consensus.

In fact, when you have seen about what has already happened with bitcoin when it was doing a consensus to determine which is BIP proposal will be used to solve the problem of bitcoin protocol and it can be affected by the politician. Bitcoin cash is the real example about that how bad consensus of bitcoin is.