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:
Jan. 13, 2009
Filed:
Feb. 07, 2002
Tomi Hakkarainen, Nokia, FI;
Rod Walsh, Tampere, FI;
Tomi Hakkarainen, Nokia, FI;
Rod Walsh, Tampere, FI;
Nokia Corporation, Espoo, FI;
Abstract
A hybrid method for a service provider to transmit decryption information (e.g., algorithms, parameters, keys) to clients in a secure manner and at low cost for use in decrypting broadcast services. The service provider uses a bi-directional channel (e.g., a GPRS channel) to receive service requests, authenticate clients and transmit currently valid decryption information (and, optionally, future decryption information) necessary to decrypt a broadcast service. The service provider transmits the encrypted service on a unidirectional channel (e.g., a DVB-T channel). The service provider preferably also changes the encryption of the service with time, and, as it does, transmits updated decryption information to its clients on the unidirectional channel. The updated decryption information is encrypted using the currently valid decryption information and may also include future decryption information and synchronization information.