The data on the magnetic stipe isn't encrypted, just encoded. There is no exploited vector. No one has cracked anything. You can read all about the encoding

The data on the magnetic stipe isn't encrypted, just encoded. There is no exploited vector. No one has cracked anything. You can read all about the encoding used and implement your own card reader with just a little Googling. You aren't 'hacking' anything to do so.