CONDITIONAL ACCESS SYSTEM AND METHOD OF USING CONDITIONAL ACCESS IMAGE

• US 20120051540A1
• Filed: 08/17/2011
• Published: 03/01/2012
• Est. Priority Date: 08/24/2010
• Status: Abandoned Application

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Paik, Eui Hyun, Han, Dong Won, MOON, Jin Young, Park, Jong Youl
• Application Number:
  US13/211,820
• Publication Number:
  US 20120051540A1
• Time in Patent Office: Days
• US Class Current: 380/200
• 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 21/26613 for generating or managing keys in general key distribution for secret or secure communication involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP] H04L9/083; network support of key management H04L63/06; key management for network security in communication control or processing H04W12/04
• 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

Abstract

Provided are a conditional access system and a method of using a conditional access image. The conditional access system according to an exemplary embodiment of the present invention includes: a service key management client allocated with a service key from a service key management server using a service key distribution protocol; a download client downloading a conditional access image using the service key and requesting updating the service key to the service key management server through the service key management client when the downloading is completed; and an execution controller encrypting and storing the conditional access image using the service key updated in accordance with the request and recovering the conditional access image using the service key reacquired through the service key management client before executing the stored conditional access image.

Claims

1. A conditional access system, comprising:

a service key management client allocated with a service key from a service key management server using a service key distribution protocol;

a download client downloading a conditional access image using the service key and requesting updating the service key to the service key management server through the service key management client when the downloading is completed; and

an execution controller encrypting and storing the conditional access image using the service key updated in accordance with the request and recovering the conditional access image using the service key reacquired through the service key management client before executing the stored conditional access image.

2. The system of claim 1, wherein the execution controller verifies whether the reacquired service key is the same as the updated service key and when both keys are the same as each other, recovers the conditional access image.

3. The system of claim 2, wherein the execution controller notifies that a use authority of the conditional access image is thieved to a user when the reacquired service key is different from the updated service key.

4. The system of claim 1, wherein the execution controller deletes the updated service key used for encryption when the storing of the conditional access image is completed.

5. A conditional access system, comprising:

a terminal that downloads a conditional access image using a service key 1, when the downloading the conditional access image is completed, requests the updating the service key 1, and encrypts and stores the conditional access image using a service key 2 resulting the updating; and

a headend that transmits a service key 3 which is being used in accordance with a request, transmits the conditional access image to a terminal that requests the conditional access image using the service key 3, and updates the service key 3 which is being used in accordance with the request from the terminal.

6. The system of claim 5, wherein when the storing of the conditional access image is completed, the terminal deletes the service key 2.

7. The system of claim 5, wherein the terminal acquires the service key 3 making a request to the headend and attempts to recover the conditional access image using the service key 3, before executing the conditional access image.

8. The system of claim 7, wherein the terminal recovers and executes the conditional access image when the service key 3 is the same as the service key 2 used for encryption.

9. The system of claim 7, wherein the terminal does not recover the conditional access image and notifies that an authority of the conditional access image is thieved to a user when the service key 3 is different from the service key 2.

10. The system of claim 5, further comprising:

another terminal that requests the downloading the conditional access image and requests updating the service key 3 at the time of downloading the conditional access image,

wherein when the service key 3 is updated by the another terminal, the terminal does not recover the conditional access image.

11. A method of using a conditional access image, comprising:

requesting the conditional access image using a service key 1 acquired from a service key management server and downloading the conditional access image;

requesting updating the service key 1 when the downloading is completed;

encrypting and storing the conditional access image using a service key 2 acquired by updating the service key 1; and

reacquiring a service key 3 from the service key management server to recover the conditional access image, before executing the conditional access image.

12. The method of claim 11, wherein the recovering includes:

verifying whether the service key 3 is the same as the service key 2; and

recovering and executing the conditional access image when both keys are the same as each other on the basis of the verification result at the verifying.

13. The method of claim 12, wherein the recovering includes notifying that an authority of the conditional access image is thieved to a user when both keys are different from each other on the basis of the verification result at the verifying.

14. The method of claim 12, wherein the recovering detects that the conditional access image is redownloaded and verifies whether the redownloading is performed by a predetermined terminal when both keys are different from each other on the basis of the verification result at the verifying.

15. The method of claim 11, wherein the storing includes deleting the service key 2 used for encryption when the storing the conditional access image is completed.

16. The method of claim 11, wherein the downloading includes:

being allocated with an ID required to request a service key; and

requesting the service key 3 using the allocated ID.

17. The method of claim 11, wherein the downloading includes encrypting and transmitting the conditional access image using the service key 1.

18. A conditional access system, comprising:

a download server downloading a conditional access image to a terminal; and

a service key management server providing a service key to the terminal and updating the service key in accordance with a request from the terminal downloading the conditional access image,

wherein the service key management server uses different service keys whenever downloading the conditional access image.

19. The system of claim 18, wherein the download server encrypts and transmits the conditional access image using the service key transmitted with the request from the terminal.

20. The system of claim 19, wherein the download server transmits the conditional access image when a currently used service key is the same as the service key transmitted.