Proof of Staked Authority (PoSA)

Proof of Authority, or Proof of Staked Authority (PoSA), attempts to solve some of the problems encountered with other PoW alternatives, namely Proof-of-Stake. It is a variant of the Proof-of-Stake consensus mechanism, where network participants use their identity and reputation instead of tokens. Proposed in 2015 by Ethereum co-founder Gavin Wood, the proof-of-authority mechanism has become one of the most popular consensus mechanisms in recent years as the blockchain community looks for ways to overcome certain weaknesses from the proof-of-work (PoW) consensus algorithm. These weaknesses are primarily high energy consumption and scaling.