Overview
pBFT was one of the first solutions to the Byzantine Generals Problem that was efficient enough for use in real-world computer systems. It is a 'leader-based' protocol that reaches consensus through multiple rounds of voting among a fixed set of nodes.
How it Works
- Pre-prepare: A leader node proposes a new block.
- Prepare: Other nodes verify the proposal and broadcast their agreement.
- Commit: Once a node receives enough 'prepare' messages, it broadcasts a 'commit' message. Once enough 'commits' are received, the block is added to the ledger.
Pros and Cons
- Pros: High transaction speed, instant finality (no forks), energy-efficient.
- Cons: Does not scale well to thousands of nodes due to the high volume of messages required between nodes.