BlackCoin ( BLK )
BlackCoin is a peer-to-peer digital currency with a distributed, decentralized public ledger, which unlike those of traditional banks is viewable and easily audited by anyone. BlackCoin was notably the first coin to use a Proof-of-Work creation cycle followed by transition to full Proof-of-stake. Proof-of-Stake is eco-friendly and efficient, and avoids the vast waste of energy and hardware overhead of Proof-of-Work based networks. Over time, BlackCoin’s core protocol has made industry-leading improvements to Proof-of-Stake security and general functionality (PoS 2.0 and PoS 3.0).