The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 19, 2000
Filed:
Aug. 08, 1997
Frank Muller, Delft, NL;
Michel Marco Drupsteen, Ouderkerk a/d Amstel, NL;
Koninklijke KPN N.V., Groningen, NL;
Abstract
In a smart card (1) electronic tickets (20) are securely stored. Ticket data is written into the fields (21, 22, 23) of a ticket (20) in a protected manner using a special code. Tickets (20) may comprise several fields, such as an entitlement field (21), a validation field (22), and a verification field (23). Different keys (K1, K2, K3) are used for each type of field at issuing, validation, and verification terminals (81, 82, 83). A further protection of the integrity of the tickets (20) is obtained by using a first storage command (UPDATE) to prepare a field when issuing the ticket (20) at the issuing terminal (81), and, a different, second storage command (WRITE) when validating the ticket (20) at the validation terminal (82). Thus, the fraudulent modification of an issued ticket (20) is prevented.