Proof-of-stake is a type of consensus mechanism used by blockchains to achieve distributed consensus. In proof-of-work, miners prove they have capital at risk by expending energy. In proof-of-stake, validators explicitly stake capital in the form of ether into a smart contract on Ethereum. This staked ether then acts as collateral that can be destroyed if the validator behaves dishonestly or lazily. The validator is then responsible for checking that new blocks propagated over the network are...