Proof of Work
Last updated 17 October 2026Last verified 17 October 2026
What is Proof of Work?
The original Bitcoin consensus mechanism, where miners compete to solve computationally intensive puzzles to validate blocks. Energy-intensive by design: the energy expenditure is the security model. Replacing the work with cheaper computation would collapse the cost of attacking the network. Still used by Bitcoin and several other networks, though Ethereum, the largest smart-contract platform, moved to Proof of Stake in 2022.
TradFi equivalentBuying the right to settle by spending real resources rather than by pledging capital. The cost of the work is the security, in the way an expensive-to-forge note resists counterfeiting.