Glossary
Proof of Authority (PoA)
A consensus mechanism in which a small set of explicitly approved, identity-bound validators take turns producing blocks, trading decentralization for speed and low overhead.
In proof of authority, the right to validate comes not from stake or hashpower but from a vetted, known identity. A limited set of approved validators — their real-world reputations on the line — take turns signing blocks in a round-robin or similar schedule. Because the participants are trusted and few, there is no race to solve puzzles or acquire tokens, so blocks finalize quickly and cheaply.
The trade-off is centralization: a closed validator set means users must trust that authority, and censorship or collusion is far easier than on permissionless chains. PoA is therefore common on testnets, private enterprise networks, and some sidechains, where throughput and predictability matter more than open participation.