Term

Finality

The point at which a transaction is considered irreversible and economically infeasible to revert.

Type:
consensus
blockchain
1
concept

Finality reflects confidence that a transaction won’t be reversed. In PoW chains, finality is probabilistic and increases with confirmations; in BFT-style consensus, finality can be explicit once validators sign a checkpoint.

Example 1.1

An exchange might require 6 confirmations for BTC deposits but fewer for BCH due to differences in block times and reorg risk tolerance.

2
factors

Factors include network hashrate, reorg depth history, fee market pressure, and attacker costs. Economic finality is reached when reorg cost exceeds potential gain.

Example 2.1

For low-value payments, merchants may accept zero-conf on BCH with risk mitigations like double-spend proofs and fraud checks.

All terms and definitions may update as the Cryptionary improves.