Finality in blockchain refers to the unchangeable confirmation of a transaction or a block of transactions.
In conventional financial systems, once a transaction is confirmed, it cannot be undone. Similarly, attaining finality on a blockchain network ensures that a transaction is permanent and cannot be modified after it has been added to the blockchain. For the blockchain to be secure and authentic, this concept is crucial.
Finality is attained by the blockchain network’s use of consensus. Different blockchain networks employ various consensus algorithms, each with a unique method of validating transactions and ensuring finality, such as proof-of-work (PoW), proof-of-stake (PoS) or practical Byzantine fault tolerance.
Finality in blockchain can be probabilistic, economic, instant, unconditional or related to the entire state of the blockchain.
On the blockchain, there are various types of finality, each of which describes a distinct degree of certainty and irreversibility with regard to transactions and blocks. The main finality types on blockchain are as follows:
Finality is probabilistic in the majority of blockchain systems, especially those that employ PoW consensus, like Bitcoin. The likelihood of reversing a transaction diminishes exponentially when blocks are put on top of a confirmed transaction after it has been included in a block.
The economic finality concept is often associated with PoS systems. A transaction is considered final in terms of economic finality if going back on it would be financially unviable. In PoS, validators or nodes are required to provide a stake as collateral, a specific quantity of cryptocurrency. If they approve fake transactions, they run the risk of losing their stake, making it
Read more on cointelegraph.com