PPCoin: Peer to Peer Crypto Currency with Proof of Stake
A peer to peer crypto currency design derived from Satoshi Nakamoto's Bitcoin. Proof of stake replaces proof of work to provide most of the network security. Under this hybrid design proof of work mainly provides initial minting and is largely non essential in the long run. Security level of the network is not dependent on energy consumption in the long term thus providing an energyefficient and more cost competitive peer to peer crypto currency. Proof of stake is based on coin age and generated by each node via a hashing scheme bearing similarity to Bitcoin's but over limited search space. Block chain history and transaction settlement are further protected by a centrally broadcasted checkpoint mechanism.