Proof of History (PoH)
Also known as: Cryptographic Timestamping, Verifiable Event Ordering, Solana Consensus
A time-based consensus mechanism that uses cryptographic timestamps to verify the sequence of blockchain events.
Proof of History (PoH) is a consensus technique developed by Solana that provides a verifiable timestamp for each event in the blockchain. Unlike traditional systems where consensus must first be reached on event order, PoH uses a cryptographic clock based on verifiable delay functions (VDFs) to establish time order before consensus. This enables high throughput and low latency by reducing coordination overhead among nodes. PoH is often combined with Proof of Stake in hybrid systems to maintain security and performance. It's central to Solana’s ability to scale efficiently.