Proof of Authority (PoA)
Also known as: Authority-Based Consensus, Validator Permission Consensus, PoA Blockchain
A consensus mechanism where pre-approved validators create new blocks, offering speed and control over decentralization.
Proof of Authority (PoA) is a consensus algorithm that relies on a limited number of trusted validators to produce blocks and secure the network. Instead of competing via computation or stake, validators are chosen based on reputation or identity, offering high throughput and energy efficiency. PoA is typically used in private or consortium blockchains where speed, compliance, and governance are prioritized over full decentralization. Popular implementations include Ethereum's Kovan testnet and chains like VeChain and xDai. While scalable, PoA can introduce centralization and trust risks.