# Blockchain Pow

Blockchain Pow is an acronym that stamds for Blockchain sProof of work. Pow (Proof of work) is an original agreement (consensus) algorithm in the Blockchain network. This algorithm is generally used to create or add a new block to the chain or confirm all the transactions. In the Pow algorithm, group of people (miners) compete against each other to complete all the transactions currently available on the network. The miners are rewarded, or they get prizes when a valid block is created successfully. The best application of Pow (Power of work) is Bitcoin.

**Moni Naor **and** Cynthia Dwork** did the first publication of Pow (Proof of work) in 1993, and it was further applied in the Bitcoin paper in the year 2008 by **Satoshi Nakamoto** & the term Pow, i.e. Proof of work was first used by **Ari Juels **and** Markus Jakobsson** in their publication in the year 1999.

The main purpose of the consensus mechanism was to bring all nodes to a particular agreement & it was to trust each other in a particular environment where nodes which are present do not trust each other.

The transactions (the process of verifying it in a block which is added) are organized in chronological order in a particular block & the new blocks which are mined are announced to the complete network, which doesn't take much time & energy. The main part which consumes more energy is solving the hard mathematical problems & link the last block to the new block invalid Blockchain.

The main working principle of Pow (Proof of work) is a mathematical puzzle which can easily prove the answer or solution. Producing evidence of work is a random process which is low in probability. This process requires a lot of trial & error until valid Proof or evidence is generated.

A block consists of the data field, cryptographic hash associated with it, Nonce and block number. The block is made valid with the help of Nonce.

A particular puzzle game creates a challenge for Bitcoin software & here, the game starts. This game makes all the miners compete to solve this challenge & this takes around ten minutes to complete this challenge. Every miner tries to find the solution for that Nonce which will satisfy the hash. As the puzzle game goes on, one miner will be the winner with great hardware and higher speed machines & internet connection. & the block which the rest of the community will verify the winner mine. A new block is added to the Blockchain but with the condition that the Nonce is correct. It provides a clear explanation of Pow (Proof of work) & concept of generating the blocks.

## Working of Bitcoin Pow

Let's study the Bitcoin Pow (Proof of work) work system:

The mining basis or the hashcash proof of work system is used by Bitcoin. Miners create a group of transactions into a particular block & after that, the miners try to mine. To mine these, the miners have to solve mathematical problems & these problems are called Pow (Proof of work) problems. Miners solve these Pows to show that they have done something or tried to find the solution for that particular problem, but the mined block by the miner should be valid.

To get accepted, the problem needs to be a lower no. When compared to the hash of that particular block & this is known as **Target Hash. **The target hash is a no. The header of a hashed block must be less than or equal to the new block, for which the miner gets a reward or award. It is always difficult to generate a particular block when the target is low.

The miner tests different Nonce till they find a suitable producer.

The miners are always rewarded. They get rewarded in Bitcoins whenever they solve the problem & add a block to the Blockchain by broadcasting the Blockchain mined.

## Features of Pow (Proof of work)

- It is always hard to find a solution for a particular mathematical problem.

- It is always easy to verify the solution.

## Cryptocurrencies which use Proof of Work( PoW)

- Dogecoin
- Litecoin
- Monero coin
- Ethereum

## Some other alternatives to the PoW

- Proof of activity
- Proof of importance
- Proof of burn
- Raft consensus
- Proof of capacity
- Proof of stake
- Proof of elapsed time