Method for providing pay-TV service based on session key

• US 20050144634A1
• Filed: 10/22/2004
• Published: 06/30/2005
• Est. Priority Date: 12/26/2003
• Status: Abandoned Application

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Kwon, O-Hyung, Lee, Soo-In, Koo, Han-Seung
• Application Number:
  US10/971,167
• Publication Number:
  US 20050144634A1
• Time in Patent Office: Days
• US Class Current: 725/31
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/2543 Billing , e.g. for subscription services payment schemes, architectures or protocols G06Q20/00; e-commerce G06Q30/00; arrangements for billing for the use of broadcast information or broadcast-related information H04H60/21
• 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 21/2668 Creating a channel for a dedicated end-user group, e.g. insertion of targeted commercials based on end-user profiles information retrieval from the Internet by querying with filtering and personalisation G06F16/9535; arrangements for replacing or switching information during the broadcast H04H20/10; push services over packet-switching network H04L12/1859; adaptation of message content in packet-switching networks H04L51/063
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/4627 Rights management associated to the content security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 21/47211 for requesting pay-per-view content payment schemes payment architectures or payment protocols G06Q20/00, G07F
• CPC Class Codes: H04N 21/63775 for uploading keys, e.g. for a client to communicate its public key to the server key management H04L9/08; network support of key management H04L63/06
• CPC Class Codes: H04N 21/6581 Reference data, e.g. a movie identifier for ordering a movie or a product identifier in a home shopping application
• CPC Class Codes: H04N 21/8355 involving usage data, e.g. number of copies or viewings allowed
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

Disclosed is a method for providing a pay-TV service based on a session key. The method includes the steps of: selecting a desired pay event using a program guide displayed on a system of the subscriber and achieving a subscriber private key; filling out a service application based on service information, signing the service application based on a digital signature scheme and encrypting the digital signed service application; transmitting the encrypted service application to a broadcasting station and waiting a response of the broadcasting station; receiving a session key and a subscription authority message from the broadcasting station, decrypting the session key and the subscription authority message and verifying the digital signature; decrypting a channel key, achieving a control word, descrambling event audio/video streams and watching the event; and if the event is terminated or the session key is not effective, stopping watching the event and deleting the session key.

Claims

1. A method for providing a pay-TV service based on a session key, the method comprising the steps of:

a) at a subscriber, selecting a desired pay event using a program guide displayed on a system of the subscriber and achieving a subscriber private key stored as encrypted data in a conditional access module (CAM) by authentication using an identifier;

b) at subscriber, filling out a service application based on service information (SI), signing the service application based on a digital signature scheme and encrypting the digital signed service application;

c) at subscriber, transmitting the encrypted service application to a broadcasting station and waiting a response of the broadcasting station;

d) at subscriber, receiving a session key and a subscription authority message from the broadcasting station, decrypting the session key and the subscription authority message and verifying the digital signature;

e) at subscriber, if an event included in the subscription authority message is started according to success of the digital signature verification, decrypting a channel key encrypted based on the session key, achieving a control word based on the channel key, descrambling event audio/video streams based on the control word and watching the event; and

f) at subscriber, if it is determined that the event is terminated according to the SI or the session key is not effective according to a validity field included in the subscription authority message, stopping watching the event based on the session key and deleting the session key in the CAM.

2. The method as recited in claim 1, wherein in the step a), the identifier uses an encryption algorithm based on a password as a standard of public key encryption.

3. The method as recited in claim 1, wherein in the step b), the service application includes an identification number of the subscriber, a date of the service application submission, a service type, a transport stream identifier defined in the SI, a source identifier defined in the SI, an event identifier defined in the SI.

4. The method as recited in claim 3, wherein in the step b), the service application further includes a series identifier.

5. The method as recited in claim 1, wherein in the step b), for the digital signature, the service application is encrypted based on the subscriber private key.

6. The method as recited in claim 1, wherein in the step b), for the encryption, the digital signed service application is encrypted based on a broadcasting station public key.

7. The method as recited in claim 1, wherein in the step d), the subscriber decrypts the encrypted subscription authority message received from the broadcasting station based on the subscriber private key, achieves the session key and the subscription authority message by decrypting the digital signature based on the broadcasting station public key.

8. The method as recited in claim 1, wherein in the step f), if a pay-per-series (PPS) service is subscribed by the subscriber, the session key of a subscribed series is secretly stored in the CAM till the subscribed series is not effective,

wherein the available date of subscribed the series can be found based on a validity and a series identifier included in the subscription authority message, and

wherein if the event, which is a PPS identical to the “

Series ID”

in the subscription authority message, the corresponding session key is used, and

wherein if the validity is terminated, the session key is deleted no matter the series ID exists.

9. A method for providing a pay-TV service based on a session key of a broadcasting station, the method comprising the steps of:

a) achieving an encrypted service application from a system of a subscriber;

b) decrypting the encrypted service application and verifying a digital signature of the service application;

c) generating a session key and a subscription authority message according to success of the digital signature verification;

d) signing the subscription authority message based on a digital signature scheme and encrypting the digital signed subscription authority message;

e) transmitting the encrypted subscription authority message to the system of the subscriber; and

f) recording service subscription information on database in order to charge fee of the pay-TV service.

10. The method as recited in claim 9, wherein in the step b), the broadcasting station decrypts the service application based on a broadcasting station private key and verifies the digital signature by decrypting the decrypted service application based on a subscriber public key,

wherein if the decryption is successful, the verification of the digital signature is successful, and

wherein the subscriber public key is achieved from a public-key certificate, which is in a directory of the broadcasting station.

11. The method as recited in claim 9, wherein in the step c), the broadcasting system prepares the session key, which is a symmetric-based key from a key server before the event is started.

12. The method as recited in claim 9, wherein in the step c), the subscription authority message includes an identification number of the subscriber, a validity, a service type, a transport stream identifier defined in the SI, a source identifier defined in the SI, an event identifier defined in the SI.

13. The method as recited in claim 12, wherein the step c), the subscription authority message further includes a series identifier.

14. The method as recited in claim 13, wherein the series identifier is effective if the subscriber subscribes to the PPS service, and wherein the event discriminated by the source ID and the event ID is regarded as the first event of the series subscribed by the subscriber.

15. The method as recited in claim 9, wherein in the step d), for the digital signature, the session key and the subscription authority message are encrypted based on the broadcasting station private key.

16. The method as recited in claim 9, wherein the step d), for the encryption, the digital signed session key and subscription authority message are encrypted based on a subscriber public key.

17. The method as recited in claim 9, wherein in the step e), the broadcasting station receives a receive confirmation message from the system of the subscriber in order to check whether the subscriber receives the session key or not.