XRP uses a consensus protocol that it calls the ‘Ripple Protocol Consensus Algorithm’ (RPCA). This works to solve the Byzantine fault tolerance (BFT) issue and helps to process transactions quickly.
The RPCA creates a a so-called ‘Unique Node List’ (UNL) where all nodes declare other nodes that they subjectively trust. A validator respects only the opinions of nodes in its UNL for validating transactions. If one validator does not trust a specific transaction, yet the majority of others do, then the transaction will go ahead.
Blockchains that use RPCA:
- XRP
