Is Bitcoin Proof-of-Work?

Is Bitcoin Proof of Work?

Bitcoin is proof of work, or PoW, the cryptocurrency's validation system is a puzzle where participants must use computing power to generate hashes to validate transactions and add them to the Blockchain.

Bitcoin remained on its path after Ethereum completed its Merge from Proof of Work (PoW) to Proof of Stake in 2022.

Bitcoin protocol requires miners to compete on Proof of Work, not stake crypto like validators.

Bitcoin's consensus model is anchored in its proof-of-work system, while the mining reward changes according to the reward schedule, which halves every 210,000 blocks. While the subsidy shift is certainly painful for miners, it’s survival for Bitcoin’s PoW. And in 2009, the Bitcoin network used Proof of Work with SHA-256.

Proof of Work (PoW) is mandatory for creating a new block for Bitcoin. In the case of Bitcoin, miners are awarded a block reward and the transaction fees when the block is added to the Bitcoin blockchain.

This happens approximately every 10 minutes, and the time for the puzzle is adjusted to maintain this. The puzzle consists of finding a number, called a nonce, that when hashed with the block's data produces a string of zeros. As stated, the difficulty level is constantly adjusted. The puzzle becomes more difficult the more miners there are.

Bitcoin's consensus rules require that a candidate block may only be added to the chain if its proof of work was performed correctly. Any failure to meet this difficulty target invalidates the block and makes it unfit to be added to the chain.