A method for using a secondary PAN is disclosed. The method includes providing a secondary PAN associated with a primary PAN, where the secondary PAN has at least one end portion that is the same as the primary PAN, but has a middle portion of that is different than the primary PAN....http://www.google.es/patents/US7818264?utm_source=gb-gplus-sharePatente US7818264 - Track data encryption
