Proof of History (PoH)
Solana's method of stamping a verifiable time order onto events before they reach consensus.
Proof of history is Solana's trick for ordering transactions without every node first agreeing on a clock. A continuous hash function acts like a cryptographic stopwatch, proving that one event came after another. Validators then process transactions in that pre-set order.
PoH is not a standalone consensus system. Solana pairs it with proof of stake to pick block producers. The payoff is speed: Solana targets thousands of transactions per second. The cost is hardware demands so steep that few people can run a validator at home.
Related terms
A consensus method where validators lock up coins as collateral instead of burning electricity to secure the chain.
Consensus MechanismThe rules a decentralized network follows to agree on one valid history without trusting any central party.
Transactions Per Second (TPS)A measure of how many transactions a blockchain can confirm each second under load.