A system for implementing at least one cryptocurrency transaction at a point-of-sale by using a mobile terminal is provided. The system is operable to provide authentication for implementing the one or more cryptocurrency transactions, wherein the system is operable to send at least one authentication request for the at least one cryptocurrency transaction from a payment terminal to a payment service hosted via one or more virtual computing machines, wherein the payment service is operable to provide a request for a PIN code at the mobile terminal; to send the PIN code from the mobile terminal via a secure channel to open a vault in the one or more virtual machines, wherein the vault contains one or more private keys which are useable for authenticating the at least one cryptocurrency transaction; and to confirm execution of the at least one cryptocurrency transaction to at least the payment terminal.