System and method for using DRM to control conditional access to broadband digital content

• US 7,698,568 B2
• Filed: 09/09/2004
• Issued: 04/13/2010
• Est. Priority Date: 11/11/2003
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Heikkilä, Tapani, Ikonen, Ari, Kangas, Mauri, Alve, Jukka
• Primary Examiner(s): Vu; Kimyen
• Assistant Examiner(s): Moran; Randal D
• Application Number:
  US10/939,078
• Publication Number:
  US 20050100167A1
• Time in Patent Office: 2,042 Days
• Field of Search: 380/281, 380/200, 380/201, 380/270, 380/271, 380/284, 713/171, 713/172, 713/189, 726/26, 726/31
• US Class Current: 713/189
• 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 21/26606 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 21/4112 having fewer capabilities than the client, e.g. thin client having less processing power or no tuning capabilities
• CPC Class Codes: H04N 21/41407 embedded in a portable device, e.g. video client on a mobile phone, PDA, laptop constructional details of equipment or arrangements specially adapted for portable computer application G06F1/1626; arrangements specially adapted for mobile receivers in broadcast systems H04H20/57
• CPC Class Codes: H04N 21/43637 involving a wireless protocol, e.g. Bluetooth, RF or wireless LAN [IEEE 802.11] arrangements for wireless networking or broadcasting of information in indoor or near-field type systems H04B10/114
• CPC Class Codes: H04N 21/4367 Establishing a secure communication between the client and a peripheral device or smart card
• 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 21/8355 involving usage data, e.g. number of copies or viewings allowed
• CPC Class Codes: H04N 7/163 by receiver means only
• 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

A system and method is disclosed for providing DRM in a broadcast environment. In accordance with the embodiment, a DRM system distributes encrypted service keys over the mobile telephone network to a mobile terminal. The mobile terminal receives the encrypted service key and uses it to decrypt encrypted content keys received from a DVB set top box. The decrypted content keys are sent to the set box over local link where they are used to decrypt encrypted broadcast content. A power management technique for mobile receivers is also disclosed that enables the receiver hardware to power off during a portion of the rendering process.

Claims

1. A method for protecting broadcast digital content comprising:

encrypting digital content with a first key;

encrypting the first key with a second key;

broadcasting the encrypted first key;

broadcasting the encrypted digital content in a number of segments;

protecting the second key and assigning rights to the second key;

transmitting, via a protected voucher, the protected second key and the assigned rights to a mobile terminal over at least one of a number of networks; and

transmitting a protected executable application to the mobile terminal, wherein the protected executable application governs key decryption, wherein the protected executable application enforces the assigned rights, and wherein the second key decrypts the protected executable application.

2. The method of claim 1 wherein each segment is broadcast in less time than is required to render the encrypted digital content contained in the segment.

3. The method of claim 1 wherein transmitting the protected second key and the assigned rights to a mobile terminal over a mobile network.

4. A method for protecting broadcast digital content comprising:

encrypting digital content with a first key;

encrypting the first key with a second key;

broadcasting the encrypted digital content in a number of segments, wherein each segment is broadcast in less time than is required to render the encrypted digital content contained in the segment;

protecting the second key and assigning rights to the second key;

transmitting, via a protected voucher, the protected second key and the assigned rights to a mobile terminal over a mobile network; and

transmitting a protected executable application to the mobile terminal, wherein the protected executable application governs key decryption, wherein the protected executable application enforces the assigned rights, and wherein the second key decrypts the protected executable application.

5. A method for viewing protected digital content comprising:

receiving and buffering a broadcasted segment of encrypted digital content and an encrypted first key with a broadcast receiver of a mobile terminal and turning off the broadcast receiver after the segment is received;

receiving, via a protected voucher, a protected second key and assigned rights at the mobile terminal over a mobile network;

receiving a protected executable application, wherein the protected executable application governs key decryption, wherein the protected executable application enforces the assigned rights, and wherein the second key decrypts the protected executable application;

decrypting the encrypted first key with the protected second key in accordance with the assigned rights;

decrypting the broadcast segment of encrypted digital content with the decrypted first key;

rendering the digital content; and

turning the broadcast receiver back on after a predetermined period.

6. The method according to claim 5 wherein the predetermined period is dictated by a parameter of the broadcasted segment.

7. The method of claim 5 wherein the predetermined period is programmed into the mobile terminal.

8. The method of claim 5 wherein the predetermined period is determined by the amount of time the digital content takes to render.

9. The method of claim 5 where the digital content is a DVB video program.

10. A system for protecting digital video broadcast content comprising:

a mobile network;

a computer connected to the mobile network;

a mobile terminal connected to the mobile network;

wherein the mobile terminal comprises a content receiving device and content rendering device;

wherein the content receiving device is programmed to receive one-way content transmissions containing a plurality of segments of encrypted digital content and at least one encrypted first key;

wherein the computer is programmed to protect a second key, create assigned rights identifying allowed uses of the second key, and send the protected second key, the assigned rights, and a protected executable application to the mobile terminal over the mobile network, wherein the protected executable application governs key decryption, wherein the protected executable application enforces the assigned rights, and wherein the protected second key and the assigned rights are sent via a protected voucher;

wherein the mobile terminal is programmed to use the protected second key in accordance with the assigned rights to decrypt the encrypted first key, and the content receiving device is further programmed to decrypt the encrypted digital content with the decrypted first key;

wherein the mobile terminal is programmed to turn off the content reception device after receiving a first segment of encrypted digital content, and then turning the content reception device on after a predetermined period of time to receive a second segment of encrypted digital content;

wherein the rendering device renders the decrypted digital content; and

wherein the second key decrypts the protected executable application.

11. A system for displaying protected digital content comprising:

a mobile network;

a mobile terminal connected to the mobile network;

the mobile terminal comprising a content receiving device capable of receiving broadcast content and a rendering device capable of rendering content;

wherein the content receiving device is programmed to receive broadcast content transmissions containing segments of encrypted digital content, at least one encrypted first key, and a protected executable application, wherein the protected executable application governs key decryption, wherein the protected executable application enforces assigned rights, and wherein the content receiving device is further programmed to send the encrypted first key to the mobile terminal over a short range network;

wherein the mobile terminal is programmed to use a protected second key in accordance with the assigned rights to decrypt the encrypted first key, and the content receiving device is further programmed to decrypt the encrypted digital content with the decrypted first key, wherein the mobile terminal receives the protected second key and the assigned rights via a protected voucher;

wherein the mobile terminal is programmed to turn off the content reception device after receiving a first segment of encrypted digital content, and then turning the content reception device on after a predetermined period of time to receive a second segment of encrypted digital content;

wherein the rendering device renders the decrypted digital content; and

wherein the second key decrypts the protected executable application.

12. The system of claim 11 wherein the encrypted digital content is a DVB transmission and the rendering device is a screen and at least one speaker.

13. A system for displaying protected digital content comprising:

a mobile terminal;

the mobile terminal comprising a content receiving device capable of receiving broadcast content and a rendering device capable of rendering content;

wherein the content receiving device is programmed to receive broadcast content transmissions containing segments of encrypted digital content, at least one encrypted first key, and a protected executable application, wherein the protected executable application governs key decryption, wherein the protected executable application enforces assigned rights, and wherein the content receiving device is further programmed to communicate the encrypted first key to the mobile terminal;

wherein the mobile terminal is programmed to use a protected second key in accordance with the assigned rights to decrypt the encrypted first key, and the content receiving device is further programmed to decrypt the encrypted digital content with the decrypted first key, wherein the mobile terminal receives the protected second key and the assigned rights in a protected voucher;

wherein the mobile terminal is programmed to turn off the content reception device after receiving a first segment of encrypted digital content, and then turning the content reception device on after a predetermined period of time to receive a second segment of encrypted digital content;

wherein at least one of the first keys is decrypted and then the encrypted digital content is decrypted and the rendering device renders the decrypted digital content; and

wherein the second key decrypts the protected executable application.

14. An apparatus comprising:

a memory having program code stored therein; and

a processor disposed in communication with the memory for carrying out instructions in accordance with the stored program code;

wherein the processor, in accordance with the program code, is configured to;

receive and buffer a broadcasted segment of encrypted digital content and an encrypted first key with a broadcast receiver of the apparatus and turn off the broadcast receiver after the segment is received;

receive, via a protected voucher, a protected second key and assigned rights at the apparatus over a mobile network;

receive a protected executable application, wherein the second key decrypts the protected executable application, wherein the protected executable application governs key decryption, and wherein the protected executable application enforces the assigned rights;

decrypt the encrypted first key with the protected second key in accordance with the assigned rights;

decrypt the broadcast segment of encrypted digital content with the decrypted first key;

render the digital content; and

turn the broadcast receiver back on after a predetermined period.

15. An article of manufacture comprising a computer readable medium containing program code that when executed causes an apparatus to perform:

receiving and buffering a broadcasted segment of encrypted digital content and an encrypted first key with a broadcast receiver of the apparatus and turning off the broadcast receiver after the segment is received;

receiving, via a protected voucher, a protected second key and assigned rights at the apparatus over a mobile network;

receiving a protected executable application, wherein the second key decrypts the protected executable application, wherein the protected executable application governs key decryption, and wherein the protected executable application enforces the assigned rights;

decrypting the encrypted first key with the protected second key in accordance with the assigned rights;

decrypting the broadcast segment of encrypted digital content with the decrypted first key;

rendering the digital content; and

turning the broadcast receiver back on after a predetermined period.