The interactive authentication system allows a consumer to interact with a base station, such as broadcast media (e.g., television and radio) or PC, to receive coupons, special sales offers, and other information with an electronic card. The electronic card can also be used to transmit a signal that...http://www.google.fr/patents/US20040031856?utm_source=gb-gplus-shareBrevet US20040031856 - Physical presence digital authentication system
Numéro de demande: 10/618,962 Numéro de publication: US 2004/0031856 A1 Date de dépôt: 14 juil. 2003 Brevet délivré: US7706838 ( Date de délivrance 27 avr. 2010)
