Establishing authority

The three main conditions that must be fulfilled for a validator to be established are as follows:

• Identity needs to be formally verified and on chain.
• Eligibility should be difficult to obtain. Examples are things such as becoming a notary public, submitting to background checks, and posting a bond.
• The set of things that must be required of each authority should be well documented, uniform, and worthy of the network's trust.

Once an authority has been established, the right to forge new blocks might be granted by adding the authority to the list of valid validators for the blockchain.

While PoA is mostly used in private chains, it can be used in public chains as well. Two public Ethereum test networks, Rinkleby and Kovan, are public blockchain networks that use PoA as their consensus mechanism.

The obvious downside of PoA is that the identity of each validator operator must be known and trusted, and the penalties for abusing that trust must be real. For global blockchains, this may not be preferred, as one of the appeals of blockchain technology is the ability to anonymously exchange value.