Cryptocurrency is a form of digital money that is designed to be secure and, in many cases, anonymous.
It is a currency associated with the internet that uses cryptography, the process of converting legible information into an almost uncrackable code, to track purchases and transfers.
Cryptography was born out of the need for secure communication in the Second World War. It has evolved in the digital era with elements of mathematical theory and computer science to become a way to secure communications, information and money online.
Source - Telegraph