A system for permitting access to a data field area in an IC card for multiple services using an individual card holder identification number for each of a plurality of data fields or for each group of data fields. Data field identification information, a personal identification number, access qualification...http://www.google.ca/patents/US4853522?utm_source=gb-gplus-sharePatent US4853522 - System for permitting access to data field area in IC card for multiple services
