No, a blockchain only needs one consensus algorithm/mechanism and Proof of Stake can entirely replace Proof of Work. To be precise tough: Steem uses Delegated Proof of Work which is a bit different than regular PoS. If you are interested, @dantheman wrote an excellent post about it.
No, a blockchain only needs one consensus algorithm/mechanism and Proof of Stake can entirely replace Proof of Work. To be precise tough: Steem uses Delegated Proof of Work which is a bit different than regular PoS. If you are interested, @dantheman wrote an excellent post about it.