What is BlackCoin? BlackCoin is a peer-to-peer cryptocurrency. BlackCoin uses a proof-of-stake system and is open-source. BlackCoin wasShow more [+] created by the developer Rat4, with the goal of proving that BlackCoin’s way of disabling proof-of-work is stable and secure. BlackCoin secures its network through a process called "minting". Transactions in BlackCoin were called "significant" in a Citibank whitepaper.