Proof of History (PoH) is a consensus mechanism that allows blockchains to cryptographically record the time or sequence of events. PoH does not replace traditional consensus mechanisms such as Proof of Stake (PoS) or Proof of Work (PoW), but works alongside them to improve efficiency.

PoH uses an immutable time verification function to ensure every event on the blockchain has an accurate timestamp. This function ensures the order of transactions without requiring time synchronization between nodes on the network, which is usually a big challenge on traditional blockchains.

How Proof of History Works

• Linear Verification Function: PoH uses a hash function that runs linearly, meaning that each input produces a unique output. This function allows every event to be recorded with a time that cannot be manipulated.
• Linked Hash: This process generates a chain hash where each output of the previous hash becomes the input for the next hash. This creates an immutable record of transaction history.
• Automatic Time Stamp: Every transaction on the blockchain is automatically timestamped without requiring additional validation from other nodes.
• Integration with Proof of Stake (PoS): On the Solana network, PoH is combined with PoS to select the validator that will process the next block. This integration speeds up the validation process and increases network throughput.