Cryptocurrencies appeared as a normal evolution of digital money. It is certain that cash is less used compared to twenty years ago, most transactions are made online or using digital money, such as banking transfers, credit cards payments, mobile applications, pay pal, etc. Cryptocurrency became the second generation of digital money, in a improved form, using current technology, and is constantly growing, exceeding the most optimistic predictions, but is also challenging and unpredictable because of it is impossible to control it anyhow.