Proof of Work and Proof of Stake are the two most common consensus mechanisms that secure blockchain networks.
Miners (in Proof of Work) and validators (in Proof of Stake) are rewarded with the network’s cryptocurrency.
They solve the problem of double spending which equals to spending the same dollar twice. Proof of Work require miners, for security, to verify their work with complicated math puzzles that need computing hardware and electricity.
Hackers who wish to seize the network would need more than half of the network’s hash power, known as a 51% attack.
The disadvantage of Proof of Work is that it requires a lot of energy and does not prevent 51% attacks.
With Proof of Stake, validators stake collateral to the network and are selected based on that proportion.
Proof of Stake uses less energy and doesn’t require specialized hardware. Attackers would need to control more than half of the total collateral staked.
Proof of stake does not address centralization concerns. Validators are selected on the size of their stake. Forking on Proof of Stake networks allows validators on multiple chains to claim multiple block rewards.
