Proof-of-stake

Proof-of-stake (PoS) protocols are a class of consensus mechanisms for blockchains that work by selecting validators in proportion to their quantity of holdings in the associated cryptocurrency. This is done to avoid the computational cost of proof-of-work (PoW) schemes. The first functioning use of PoS for cryptocurrency was Peercoin in 2012, although its scheme, on the surface, still resembled a PoW.