Transaction Finality
Also known as: Blockchain Finality, Confirmed Transaction, Irreversible Transaction
The assurance that a blockchain transaction is permanently recorded and cannot be reversed or altered.
Transaction finality refers to the point at which a blockchain transaction becomes irreversible and is guaranteed to remain part of the canonical chain. In Proof of Work systems like Bitcoin, finality is probabilistic and increases with the number of subsequent confirmations. In Proof of Stake systems, finality can be deterministic, using finality gadgets like Ethereum’s Casper FFG. Finality is essential for financial applications, preventing double-spends and ensuring transaction trust. Different consensus mechanisms offer varying levels of speed and assurance for achieving finality.