proof of work

Definitions

1. A consensus mechanism in which participants must expend measurable computational effort to propose a valid block, making attacks expensive rather than impossible. In Bitcoin, miners repeatedly hash a candidate block with varying nonces until the result falls below a difficulty target; finding such a hash is costly, while verifying it is trivial, and that asymmetry is the entire security argument. The network adjusts difficulty to hold block times roughly constant regardless of how much hardware joins. Proof of work buys Sybil resistance by tying influence to energy rather than identity, but the same property makes it enormously power-hungry and pushes mining toward specialised ASICs and cheap electricity. Proof of stake is the principal alternative, substituting economic collateral that can be slashed for physical work that cannot be recovered.

   In plain English: A system where computers must do expensive, hard work to earn the right to add transactions to the blockchain. The waste is the point — it makes cheating too costly.

   Example: Bitcoin's proof of work consumes more electricity annually than some countries, which is either a feature or a bug depending on who you ask.

Related Terms

• mining (crypto)
• proof of stake
• consensus mechanism
• Split Brain

Collections Including This Term

• Web3 and Blockchain