Proof of history (PoH) is an upgraded version of the proof of stake (PoS) consensus mechanism and is used to secure a blockchain network and validate transactions. A blockchain utilizing a PoH consensus algorithm is more efficient than a PoS network as it uses timestamps to improve block production.
Proof of history uses Verifiable Delay Functions (VDFs), where steps for validation are pre-determined. This helps set the required time for each step involved in block production, reducing the processing load on each node within the blockchain.
Solana is one of the most popular blockchains that use a proof of history consensus mechanism. The PoH consensus allows the network to offer higher throughput without imposing too much load on its nodes for processing blocks.
The Solana blockchain can process as many as 60,000 transactions per second (TPS), thanks to the PoH consensus. However, experts argue that the consensus algorithm may have more security flaws than more established algorithms, such as proof of work or proof of stake.