Mining

Mining is the process where network participants, known as miners, use computational power to validate transactions, solve cryptographic puzzles, and add new blocks to a blockchain. Miners compete to secure the network and earn rewards in cryptocurrency, such as newly minted coins and transaction fees.

Miners gather unconfirmed transactions into a candidate block. They then adjust a random value called a nonce until the block's data, when hashed using an algorithm like SHA-256 in Bitcoin, produces a hash below a target difficulty level. This proof-of-work requires massive trial-and-error calculations. The first miner to succeed broadcasts the block. Other nodes verify it quickly and add it to the chain if valid.

Mining matters because it achieves decentralized consensus. It prevents attacks like double-spending by making it computationally expensive to alter the blockchain. Rewards incentivize honest participation, ensuring network security without central control. For example, Bitcoin's mining hashrate exceeds exahashes per second, deterring 51% attacks.

Key characteristics include high energy use and specialized hardware. Early Bitcoin mining used CPUs, then GPUs, FPGAs, and now ASICs for efficiency.

• ASIC mining: Custom chips for one algorithm, dominant in Bitcoin.
• GPU mining: Versatile for altcoins like Ethereum Classic.

Not all blockchains use mining; Proof-of-Stake alternatives avoid it to cut energy costs.