An IC card 3 has an ID number ID0, for permitting itself to be identified, stored in memory provided therein. The IC card also has additional ID numbers ID1 to IDn stored in memory areas 17-1 to 17-n that are secured therein so as to be allocated to the individual providers that manage the reader/writers...http://www.google.de/patents/US6747546?utm_source=gb-gplus-sharePatent US6747546 - Data communication transponder and communications system employing it
