Peercoin (PPC) first came online in 2012, making it one of the earliest pioneering blockchains. The key innovation of Peercoin is its invention of proof-of-stake, an alternative consensus protocol to Bitcoin’s proof-of-work. Proof-of-work blockchains are secured by proving the consumption of a costly limited resource: electricity. Proof-of-stake replaces this expensive security protocol by utilizing an alternative scarce resource: time. Due to the cost efficient nature of proof-of-stake’s time based consensus rules, Peercoin is capable of allowing any network connected computer to participate in the blockchain’s security process. This efficiency strengthens Peercoin by growing the number of security providers and ensuring that security can be sustained over the long-term.