"if I give you a special code" sounds similar to Blik system in Poland - sender generates 6 digit code valid for 120 sec, gives it to donor (shop, person, atm) and the founds are transfered with additional approval by sender. This way you can make payment via non-trustworthy places such as Internet coffies or withdraw money in atm without compromising chip/pin on card. Additionally, if you connect you phone to blik, you are able to receive instant blik money transfers by using phone number as destination. Really handy!