Nakamoto Consensus
consensus · proof-of-work
Probabilistic consensus in which nodes validate rules and prefer the valid chain with the most accumulated proof of work.
Nakamoto consensus combines proof-of-work block production, independent node validation, peer-to-peer propagation, and a rule for selecting the valid history with the most accumulated work.
Finality is probabilistic rather than immediate. Each additional block built on a transaction raises the work an attacker would need to replace that history, but no fixed confirmation count is universally safe for every value and attacker.
The mechanism assumes that honest or economically aligned miners can outpace an attacker over the relevant period and that users run software enforcing the intended rules. The most-work rule compares valid chains; it does not make an invalid block acceptable.
Related terms
Proof of Work (PoW)
→A consensus mechanism that makes block production require verifiable computational work.
mining · blockchain · consensus
Confirmations
→The count of blocks confirming a transaction, usually including the block that first contains it.
security · blockchain
Fork
→A fork is a blockchain divergence caused by competing blocks, software changes, or incompatible consensus rules.
blockchain · event
Node
→Software that participates in a peer-to-peer network by validating, serving, relaying, or requesting blockchain data.
network · blockchain
Majority Attack
→A proof-of-work attack in which coordinated hash power can outpace the honest chain and reorganize recent valid history.
security · consensus