Nokia Corporation

Tomi Hakkarainen

Harri Juhani Pekonen

Rod Walsh

Juha-Pekka Luoma

Pasi Kärkäs

Pasi K&auml;rk&auml;s

The present invention provides methods and apparatus for filtering a broadcast data stream that can support data flow, e.g. IPv6 packets. The present invention utilizes common filtering for packet segments that are common among IPv6 packets. Segments that are not common are separately filtered. A set of rules is applied to the filtered segments in order to determine whether corresponding packets should be subsequently processed. The present invention is applicable to numerous application including MPEG multicast services.

Boolean protocol filtering

Methods and systems are provided for filtering digital data formatted in packets. A filter module contains a plurality of filters and is coupled to a filter mapping module. The filter mapping module receives the identification of clusters of discrete segments of a packet and selects a group of fixed length filters to filter the clusters.

Fixed length filtering to filter clusters of discrete segments of data

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.

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Nokia, Finland

Tomi Hakkarainen