CONDITIONAL ACCESS SYSTEM

• US 20080192934A1
• Filed: 04/17/2008
• Published: 08/14/2008
• Est. Priority Date: 06/29/2001
• Status: Abandoned Application

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Nieminen, Ari, Nelger, Rickard
• Application Number:
  US12/104,957
• Publication Number:
  US 20080192934A1
• Time in Patent Office: Days
• US Class Current: 380/258
• CPC Class Codes: H04N 21/26606 for generating or managing entitlement messages, e.g. Entitlement Control Message [ECM] or Entitlement Management Message [EMM] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 21/4622 Retrieving content or additional data from different sources, e.g. from a broadcast channel and the Internet web site content organization and management for information retrieval from the Internet G06F16/958; transmission by internet of broadcast information H04H60/82; stock exchange data over packet-switching network H04L12/1804; push services including data channel over packet-switching network H04L12/1859
• CPC Class Codes: H04N 21/4623 Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 21/63345 by transmitting keys key distribution for secret or secure communication H04L9/08; network support of key management H04L63/06
• CPC Class Codes: H04N 7/162 Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing

Abstract

A conditional access system in which entitlement control messages (ECMs) containing the encryption keys used to encrypt a program transmission, are sent to a set-top box over a secure communications channel separate from the channel used for transmission of the encrypted program.

Claims

1. An apparatus comprising:

a transmitter configured to;

transmit control messages associated with decoding a scrambled broadcast stream separately from the scrambled broadcast stream if access is authorized; and

not transmit the control messages if access is not authorized,

wherein access is authorized when a subscription exists between a user and a service provider in a home network region.

2. The apparatus of claim 1, wherein the transmitter is associated with a second service provider different from the service provider in the home network region.

3. The apparatus of claim 2, wherein the second service provider is associated with a roaming network region.

4. The apparatus of claim 1, further comprising a subscription authorization module configured to check whether the subscription between the user and the service provider exists.

5. The apparatus of claim 1, wherein the subscription includes roaming privileges.

6. The apparatus of claim 1, wherein the transmitter is configured to transmit the control messages in response to receiving a request for the control messages.

7. The apparatus of claim 1, wherein the transmitter is configured to transmit the control messages through a virtual private network.

8. The apparatus of claim 1, wherein the transmitter is further configured to modify one or more control words in the control messages at a predetermined interval.

9. A method comprising:

determining whether a subscription exists between a user and a service provider in a home network region; and

in response to determining that the subscription exists, transmitting control messages associated with decoding a scrambled broadcast stream separately from the scrambled broadcast stream.

10. The method of claim 9, wherein the control messages are transmitted in a roaming network region different from the home network region.

11. The method of claim 10, wherein transmitting the control message is performed over a first channel different from a second channel over which the scrambled broadcast stream is transmitted.

12. The method of claim 9, wherein determining whether the subscription exists between the user and the service provider in the home network region includes determining whether the subscription includes roaming privileges.

13. The method of claim 9, further comprising receiving a request for the control messages and wherein determining whether a subscription exists is performed in response to receiving the request.

14. The method of claim 9, further comprising encrypting the control messages for transmission.

15. The method of claim 9, wherein the control messages are transmitted from a second service provider associated with a roaming network region different from the service provider in the home network region.

16. The method of claim 15, further comprising revoking subscription rights in the home network region upon transmitting the control messages in the roaming network region.

17. The method of claim 9, wherein the scrambled broadcast stream is transmitted over a first channel and the control messages are transmitted over a second channel different from the first channel.

18. The method of claim 17, wherein the second channel is a virtual private network.

19. The method of claim 9, further comprising modifying one or more control words in the control messages is changed at predetermined intervals.

20. The method of claim 9, wherein the control messages further include access criteria for accessing a service through which the scrambled broadcast stream is transmitted.