Nominated Proof of Stake (NPoS) is the consensus algorithm used in Substrate-based blockchains, such as Reef Chain, Polkadot, Kusama, and Edgeware. The main actors involved in NPoS are Validators and Nominators. NPoS ensures:
- Decentralization and fair representation through ‘proportional justified representation’, which assigns slots to validators proportional to their nominations.
- High security through ‘maximin support’, which distributes the nominated stake such that every validator in the active set has roughly the same amount of stake backing it.