> ## Documentation Index
> Fetch the complete documentation index at: https://docs.theblockchainlibrary.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Proof of Authority

> A consensus model where a known and authorized set of validators produces and validates blocks.

# Proof of Authority

A consensus model where a known and authorized set of validators produces and validates blocks.

## Definition

A consensus model where a known and authorized set of validators produces and validates blocks.

## Why it matters

Consensus concepts explain how independent nodes agree on one shared history without a central coordinator.

## How it works

The network selects a group of nodes to act as validators. These nodes are vetted and their identities are stored on the blockchain. When a new block needs to be added, these nodes take turns proposing and signing off on the transactions, ensuring consensus without the need for complex computation.

## Real-world example

The VeChainThor blockchain uses a Proof of Authority mechanism to manage supply chain logistics.

## Advantages

* High transaction throughput
* Energy efficiency
* Low operational costs

## Limitations

* Requires central trust
* Lower decentralization
* Vulnerable to validator identity compromise

## Common misconceptions

* It is not a truly decentralized protocol like Bitcoin.
* It does not provide the same security guarantees as permissionless networks.

## Related knowledge

* [Block Producer](/generated/v2/glossary/block-producer) — term
* [Finality](/generated/v2/glossary/finality) — term
* [Proof of Stake](/generated/v2/books/proof-of-stake) — term
* [Validator](/generated/v2/glossary/validator) — term

***

**Canonical knowledge ID:** `glossary:proof-of-authority`