What it is
On Solana, a program is a smart contract. The program does not hold the data. The data sits in accounts, and a transaction asks a program to run. Proof of history is a chain of SHA-256 hashes that puts events in order. Solana is classed as proof of stake.
- Source: Core concepts, Solana documentation · read 21 Oct 2026
- Source: Proof of History: How Solana brings time to crypto, Solana (29 Nov 2021) · read 21 Oct 2026
- Source: Coin Data by ID, CoinGecko API · read 21 Oct 2026
Technical detail
The proof-of-history article is dated 29 Nov 2021. The proof-of-stake class is from CoinGecko on 21 Oct 2026. Those pages were not opened again on 26 Oct. Who can change the rules was not added.