Criptocurrencies are popular convertible virtual currencies, as they use security mechanisms such as cryptography for creating units of the currency and controlling the transaction. Th e main property of criptocurrencies is that they provide anonymity for the transaction, as they work based on Blockchain technology. Bitcoin is one of the most important criptocurrencies on the market. Whereas we like it or not, it seems that Bitcoin has become a powerful payment instrument, but also a payment system. Th e national Governments face now a new challenge: the necessity of regulating Bitcoin. But Bitcoin is incompatible with any kind of centralized control. We can only imagine that eff ective regulations can exist only through worldwide c...