Signal tracking system and method

• US 20040076297A1
• Filed: 08/26/2003
• Published: 04/22/2004
• Est. Priority Date: 02/26/2001
• Status: Active Grant

• Current Assignee: Nagravision SA (Kudelski SA)
• Original Assignee: Nagravision SA (Kudelski SA)
• Inventors: Goeke, Maxime
• Granted Patent: US 7,233,670 B2
• Time in Patent Office: Days
• US Class Current: 380/211
• CPC Class Codes: H04H 20/103 Transmitter-side switching
• CPC Class Codes: H04H 60/23 using cryptography, e.g. encryption, authentication, key distribution
• CPC Class Codes: H04N 21/222 Secondary servers, e.g. proxy server, cable television Head-end provisioning of proxy services in data packet switching networks H04L67/56
• CPC Class Codes: H04N 21/2343 involving reformatting operations of video signals for distribution or compliance with end-user requests or end-user device requirements video transcoding H04N19/40; media packet handling at the source H04L65/762
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/8358 involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467
• CPC Class Codes: H04N 7/165 Centralised control of user terminal subsequent to an upstream request signal H04N7/17345; Registering at central by two-way working H04N7/17309

Abstract

The objective of the present invention is to propose a system and a method for determining the origin of a signal received by a pay television subscriber in a given region.

This objective is achieved by a system comprising encryption means located at a main operator, transmission means of an encrypted video signal towards at least one local operator, and decryption means at the local operator, characterised in that the decryption means comprise identification means replacing all or part of the decrypted video signal with an identification signal characterising the decryption means.

Claims

1. System for identifying the origin of a signal broadcasted to a subscriber, comprising encryption means located at a main operator, transmission means of an encrypted video signal towards at least one local operator, and decryption means located at this local operator, this local operator having from then on the decrypted signal for broadcasting to its subscribers, characterised in that the decryption means comprise substitution means replacing all or part of the decrypted video signal with an identification signal characterising the decryption means.

2. System for identifying the origin of a signal according to claim 1, characterised in that the decryption means comprise a decryption module and a security module.

3. System for identifying the origin of a signal according to claim 2, characterised in that the identification signal comprises an identifier of the decryption module and an identifier of the security module.

4. System for identifying the origin of a signal according to claims 1 to 3, characterised in that the identification signal is placed in a randomly defined area on the screen.

5. System for identifying the origin of a signal according to claims 1 to 3, characterised in that the identification signal is overlaying the current image such as a background.

6. Method for identifying the origin of a signal broadcasted to a subscriber, this method comprising the following stages:

encryption of a video signal by a main operator,

transmission of this encrypted signal to several local operators,

decryption of the encrypted signal by a decryption module (MS1, MS2) of an enabled local operator (OPL1, OPL2) and disposal of the decrypted signal,

broadcasting of this signal to the subscribers of said local operator (OPL1, OPL2),

characterised in that it consists in;

substituting by the decryption module all or part of the decrypted signal with an identification signal identifying said decryption module.

7. Method according to claim 6, characterised in that the identification signal replaces a part of the image formed by the decrypted signal in any region of the image.

8. Method according to claim 6, characterised in that the identification signal is overlaying the current image such as a background.

9. A method according to claims 6 to 8, characterised in that it consists in sending an identification command by the main operator to one or several decryption modules.