Inter-entity coupling method, apparatus and system for content protection

• US 20070061568A1
• Filed: 04/21/2006
• Published: 03/15/2007
• Est. Priority Date: 09/15/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: Kim, Wuk, Hwang, Sung-Oh, Lee, Byung-Rae
• Granted Patent: US 8,327,136 B2
• Time in Patent Office: Days
• US Class Current: 713/163
• CPC Class Codes: H04L 2463/101 applying security measures for digital rights management data processing systems or methods, specially adapted for commerce, e.g. marketing, shopping, billing, auctions or e-commerce G06Q30/00
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/0478 applying multiple layers of encryption, e.g. nested tunnels or encrypting the content with a first key and then with at least a second key cryptographic mechanisms or cryptographic arrangements using a plurality of keys or algorithms H04L9/14
• CPC Class Codes: H04L 63/065 for group communications cryptographic mechanisms or cryptographic arrangements for key management involving conference or group key H04L9/0833

Abstract

Disclosed is an inter-entity coupling method for protecting content in a broadcast environment including a broadcast network and a terminal, the broadcast network having a Broadcast Service Application (BSA), a Broadcast Service Distribution (BSD), and a Broadcast Service Management (BSM), the inter-entity coupling method including performing, by the terminal, a registration process for obtaining a group key for the terminal; after the registration process is completed, performing, by the terminal, a service joining process for requesting service joining, and receiving, by the terminal, a Rights Object (RO) about the content from a message, which is received in response to the request, based on the obtained group key; obtaining a traffic key by using the RO, if a traffic key message is received after the service joining process is completed; receiving encrypted content in the terminal; and decrypting the encrypted content by using the traffic key.

Claims

1. An inter-entity coupling method for protecting content in a broadcast environment including a broadcast network and a terminal, the broadcast network having a Broadcast Service Application (BSA), a Broadcast Service Distribution (BSD), and a Broadcast Service Management (BSM), the inter-entity coupling method comprising:

performing, by the terminal, a registration process for obtaining a group key for the terminal;

requesting a service joining process by the terminal;

receiving, by the terminal, in response to the service joining request, a message including a Rights Object (RO) corresponding to the content and being based on the obtained group key;

obtaining a traffic key using the RO, if a traffic key message is received after the service joining process is completed;

receiving encrypted content in the terminal; and

decrypting the encrypted content using the traffic key.

2. The inter-entity coupling method as claimed in claim 1, wherein the registration process comprising:

when a registration request message is received from the terminal through the BSM, transmitting, by the BSD, a registration response message to the terminal in response to the registration request message, the registration response message including group key corresponding to a group to which the terminal belongs; and

verifying, by the terminal, the received registration response message to obtain the group key.

3. The inter-entity coupling method as claimed in claim 2, wherein the terminal corresponds to a terminal using a broadcast channel, and transmits the registration request message to the BSM through a specific agency.

4. The inter-entity coupling method as claimed in claim 2, wherein, when the terminal corresponds to a terminal using a bidirectional channel and the BSM directly transfers the registration response message.

5. The inter-entity coupling method as claimed in claim 2, wherein the step of obtaining the group key comprising:

when the registration response message is received from the BSD, checking an electronic signature field and a time field included in the registration response message for verification; and

when the verification is successful, decrypting the encrypted group key included in the registration response message using a public key of the terminal to obtain the group key.

6. The inter-entity coupling method as claimed in claim 1, wherein the service joining process comprising:

when a service joining request message is received from the terminal, generating, by the BSM, the RO using a service key;

transferring, by the BSM, a service joining response message including an RO encrypted with the group key to the BSD;

broadcasting, by the BSD, the service joining response message to the terminal; and

decrypting, by the terminal, the encrypted RO included in the service joining response message using the obtained group key to obtain the RO.

7. The inter-entity coupling method as claimed in claim 1, wherein the service joining process comprising:

when a service joining request message is received from the terminal through a bidirectional channel, generating, by the BSM, the RO using a service key;

transferring, by the BSM, a service joining response message including an RO encrypted with the group key to the terminal; and

decrypting, by the terminal, the encrypted RO included in the broadcasted service joining response message using the obtained group key to obtain the RO.

8. The inter-entity coupling method as claimed in claims 6, wherein the service joining request message includes an ID (identification) of a service which the terminal is to join.

9. The inter-entity coupling method as claimed in claim 1, wherein the RO includes a service key which is an encryption key assigned when the terminal joins a specific service, and the traffic key is an encryption key used for encrypting the content.

10. The inter-entity coupling method as claimed in claim 1, wherein the traffic key is obtained, by the terminal, by decrypting an encrypted traffic key using a service key included in the obtained RO, after the BSM transfers the traffic key message to the BSD, and the BSD transmits the traffic key message to the terminal, the traffic key message including the encrypted traffic key formed by encrypting the traffic key with a service key.

11. An inter-entity coupling method for protecting content in a broadcast environment including a broadcast network and a terminal, the broadcast network including a Broadcast Service Application (BSA), a Broadcast Service Distribution (BSD), and a Broadcast Service Management (BSM) the inter-entity coupling method comprising:

receiving, in the BSM, a registration request message from the terminal;

transmitting, from the BSM to the terminal, a registration response message including a group key corresponding to a group to which the terminal belongs;

obtaining, by the terminal, the group key from the received registration response message;

requesting joining in a service by the terminal;

generating and transmitting, by the BSM, a message including a Rights Object (RO) corresponding to the service;

obtaining, by the terminal, the RO about the service from the received message by using the group key;

transferring, from the BSM to the BSA, a traffic key for encrypting content;

receiving, in the terminal, a traffic key message;

obtaining, by the terminal, the traffic key from the traffic key message by using the RO;

receiving, in the BSA, content from a content provider;

encrypting the received content using the traffic key;

transmitting the encrypted content to the terminal; and

decrypting, by the terminal, the encrypted content using the traffic key.

12. The inter-entity coupling method as claimed in claim 11, wherein the terminal corresponds to a terminal using a broadcast channel, and transmits a message to the BSM through a specific agency.

13. The inter-entity coupling method as claimed in claim 11, wherein the step of transmitting the registration response message comprising:

receiving, by the BSM, a registration request message from the terminal through a specific agency;

generating a message, including the group key encrypted with a public key of the terminal, in response to reception of the registration request message, and transferring the generated message including the encrypted group key to the BSD; and

broadcasting, by the BSD, the received message including the encrypted group key to the terminal.

14. The inter-entity coupling method as claimed in claim 11, wherein the step of transmitting the registration response message comprising:

receiving, by the BSM, a registration request message from the terminal; and

generating, by the BSM, a message including the group key encrypted with a public key of the terminal, in response to reception of the registration request message, and transferring the generated registration response message to the terminal through a bidirectional channel.

15. The inter-entity coupling method as claimed in claim 11, wherein the step of obtaining the group key comprising:

when the registration response message is received by the terminal from the BSD, checking, by the terminal, an electronic signature field and a time field included in the registration response message for verification; and

when the verification is successful, decrypting an encrypted group key included in the registration response message using a public key of the terminal to obtain the group key.

16. The inter-entity coupling method as claimed in claim 11, wherein the step of generating and transmitting the message including the RO comprising:

when the terminal corresponds to a terminal using a broadcast channel, transmitting a service joining request message to the BSM through a specific agency;

generating, by the BSM, the RO using a service key, and transferring a service joining response message including an RO encrypted with the group key to the BSD, and

broadcasting, by the BSD, the service joining response message to the terminal.

17. The inter-entity coupling method as claimed in claim 11, wherein the step of generating and transmitting the message including the RO comprising:

transmitting, by the terminal, a service joining request message to the BSM; and

generating, by the BSM, the RO using a service key, and transferring a service joining response message including an RO encrypted with the group key to the terminal through the bidirectional channel.

18. The inter-entity coupling method as claimed in claim 11, wherein the step of obtaining the traffic key comprising:

decrypting, by the terminal, the encrypted RO by using the group key, thereby obtaining the RO;

receiving by the terminal the traffic key message generated by the BSA through the BSD; and

decrypting an encrypted traffic key using a service key included in the obtained RO after receiving the traffic key message to obtain the traffic key.

19. The inter-entity coupling method as claimed in claim 18, wherein the traffic key message includes an encrypted traffic key generated by encrypting the traffic key with a service key corresponding to an encryption key generated according to the service joining.

20. An inter-entity coupling system for protecting content in a broadcast environment, the inter-entity coupling system comprising:

a terminal;

a content provider for generating content and transferring the generated content;

a Broadcast Service Application (BSA) for encrypting the content using a traffic key, and transmitting the encrypted content to the terminal through a Broadcast Service Distribution (BSD);

a Broadcast Service Management (BSM) for performing a registration process and a service joining management process with the terminal, and generating a traffic key message including a traffic key used for encrypting the content;

the BSD for receiving the traffic key message from the BSM and transmitting the received traffic key message to the terminal; and

wherein the terminal obtains the traffic key using a Rights Object (RO) acquired at a service joining when the traffic key message is received, and decrypts the encrypted content using the obtained traffic key.

21. The inter-entity coupling method as claimed in claim 20, wherein the BSM receives a registration request message from the terminal through bidirectional channel, and generates and transmits a registration response message including a group key corresponding to a group including the terminal to the terminal, which includes group key about a group having the terminal, and

the terminal verifies the registration response message received from the BSM, to obtain the group key.

22. The inter-entity coupling method as claimed in claim 21, wherein the BSM receives the registration request message from the terminal through a specific agency when the terminal corresponds to a terminal using a broadcast channel, and transmits the generated registration response message to the terminal through the BSD.

23. The inter-entity coupling method as claimed in claim 21, wherein the BSM generates and transmits a service joining response message including an RO corresponds to the content when a service joining request message is received from the terminal, and

the terminal obtains the RO from the received service joining response message by using the group key.

24. The inter-entity coupling method as claimed in claim 23, wherein the BSM receives the service joining request message through a specific agency when the terminal corresponds to a terminal using a broadcast channel, and transmits the generated service joining response message to the terminal through the BSD.

25. The inter-entity coupling method as claimed in claim 20, wherein the BSA includes a Content Provider-Encryption (CP-E) component for encrypting the content.

26. The inter-entity coupling method as claimed in claim 20, wherein the BSM includes a Content Provider-Management (CP-M) component for generating an encryption key for the terminal and managing joining of the terminal.

28. The inter-entity coupling method as claimed in claim 21, wherein the BSD includes a Stream Distribution (SD) component for broadcasting stream content encrypted by the BSA, and a File Distribution (FD) component for broadcasting file content encrypted by the BSA.

29. The inter-entity coupling method as claimed in claim 28, wherein the terminal comprising:

an SD-Client (SD-C) component for receiving encrypted streaming content transmitted from the SD component;

an FD-Client (FD-C) component for receiving a message or an encrypted file content transmitted from the FD component;

a CP-Decryption (CP-D) component for respectively decrypting the streaming content and the decrypting file content which are transmitted from the SD-C component and the FD-C component respectively; and

a CP-Client (CP-C) component for obtaining an encryption key used for decrypting the encrypted content while performing the registration and service joining processes with the CP-M component of the BSM, and transferring the obtained encryption key to the CP-D component.

30. The inter-entity coupling method as claimed in claim 20, wherein the BSD receives a service key and the traffic key from the BSM, generates a traffic key message including a traffic key encrypted with the service key, and transmits the traffic key message including the encrypted traffic key to the terminal through a broadcast channel.

31. The inter-entity coupling method as claimed in claim 20, wherein the BSM generates a group key for encrypting a service key, wherein the encryption key corresponds with a group including the terminal, the service key being an encryption key issued when the terminal joins a specific service, and a traffic key being an encryption key used for encrypting content provided from the content provider.

32. An inter-entity coupling system for protecting content in a broadcast environment including a broadcast network and a terminal, the broadcast network having a Broadcast Service Application (BSA), a Broadcast Service Distribution (BSD), and a Broadcast Service Management (BSM), the inter-entity coupling terminal comprising:

a first component for receiving an encrypted stream content from the BSD;

a second component for receiving an encrypted file content and at least an encryption key from the BSD;

a third component for encrypting the encrypted content transmitted from the BSD;

a fourth component for transmitting at least an encryption key received from the BSM to the third component;

wherein the fourth component performs a registration process and a service joining process.

33. An inter-entity coupling terminal apparatus for protecting content in a broadcast environment including a broadcast network and the terminal, the broadcast network including a Broadcast Service Application (BSA), a Broadcast Service Distribution (BSD), and a Broadcast Service Management (BSM), the inter-entity coupling terminal apparatus comprising:

a Digital Rights Management (DRM) module for managing a registration, service joining, and use of content;

a communication module for exchanging a message with the BSM, and receiving a traffic key message and an encrypted service from the BSD; and

an authentication module for obtaining at least an encryption key by verifying a message received from at least one of the BSM and the BSD.

34. The inter-entity coupling terminal apparatus as claimed in claim 33, wherein the DRM module comprising:

a registration module for performing an operation based on a registration process;

a rights management module for managing analysis and use of a Rights Object (RO) acquired at the service joining;

a key stream management module for performing decryption of an encrypted traffic key with a service key assigned at the service joining;

a content decryption module for performing decryption of encrypted content with the traffic key; and

a DRM manager module for controlling operations of the modules, respectively.

35. The inter-entity coupling terminal apparatus as claimed in claim 33, wherein the authentication module comprising:

an authentication manager module for controlling protocol execution and managing an authentication function;

an encryption/decryption module for executing encryption and decryption operations;

a digital signature module for signing an electronic signature; and

a MAC (media access control) module for executing a MAC operation.