Proof of History
Proof of History (PoH) is Solana's clock-before-consensus trick: a verifiable delay function stamps every event with a cryptographic timestamp, so validato
Proof of History (PoH) is Solana’s clock-before-consensus trick: a verifiable delay function stamps every event with a cryptographic timestamp, so validators agree on *order* without talking to each other first. Consensus then only has to agree the sequence is valid, which is much faster.
Why it matters
PoH is why Solana is so fast — ordering is the expensive part of consensus, and PoH pre-solves it. The trade-off is hardware: running the delay function at speed needs serious machines, which pushes validators toward data centers and feeds Solana’s cloud-concentration weakness.