Crypto currency is a kind of electronic money with the possibility of limited "emission" beyond the control of the state structures of any country, which makes such currency a serious butcher for Big Brother.
The issuance of crypto currency is based on the calculations used in encryption algorithms, hence the Greek prefix "crypto-". With these calculations, with a super-powerful computer, anyone can do it. Therefore, in crypto-currencies, there is the term "mining" , that is, "mining" of currency on supercomputers installed in greedy enthusiasts.
The most famous crypto currencies today are Bitcoin , Litecoin, Ethereum, Ripple and Monero. Bitcoin is already being accepted in the West as a means of payment in many electronic and real stores.
The rate bikkoyna to the dollar in 2017 exceeded 7000 dollars for 1 bitcoin, which caused an unprecedented HYIP and hysterics.