Conditional access system for digital data by key decryption and re-encryption

• US 20060179489A1
• Filed: 12/18/2003
• Published: 08/10/2006
• Est. Priority Date: 06/22/2001
• Status: Abandoned Application

• Current Assignee: Octalis SA
• Original Assignee: Octalis SA
• Inventors: Mas Ribes, Joan-Maria
• Application Number:
  US10/742,639
• Publication Number:
  US 20060179489A1
• Time in Patent Office: Days
• US Class Current: 726/27
• CPC Class Codes: H04N 2005/91364 the video signal being scrambled
• CPC Class Codes: H04N 21/4147 PVR [Personal Video Recorder] H04N5/76 takes precedence ; arrangements for broadcast with accumulation-type receivers H04H20/40
• CPC Class Codes: H04N 21/4181 for conditional access
• CPC Class Codes: H04N 21/4334 Recording operations recording of a television signal H04N5/76; arrangements for recording or accumulating broadcast information or broadcast-related information H04H60/27
• CPC Class Codes: H04N 21/43622 Interfacing an external recording device
• CPC Class Codes: H04N 21/4367 Establishing a secure communication between the client and a peripheral device or smart card
• CPC Class Codes: H04N 21/4408 involving video stream encryption, e.g. re-encrypting a decrypted video stream for redistribution in a home network
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection
• 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

The invention relates to a multi layered conditional access method for processing a protected digital content between a content protector, an intermediate receiver, and final destination means. The method comprises: a) the encryption by the content protector of a key or keys for accessing protected digital content, b) the transmission from the content protector to the intermediate receiver of the encrypted key or keys, c) the decryption and re-encryption of the key or keys by the intermediate receiver, d) the transmission of the re-encrypted key or keys to a final destination device, and e) the decryption of the re-encrypted key or keys by the final destination device. The invention is further related to a storage medium having recorded thereon encrypted program data in a data format able to perform the process of the invention, and to an insertable electronic smart card for use in a multi layered conditional access system.

Claims

1. A multi layered conditional access method for processing a protected digital content between a content protector, an intermediate receiver, and final destination device, comprising:

a) encrypting, by the content protector, a key or keys for accessing said protected digital content;

b) transmitting, from the content protector to the intermediate receiver, said encrypted key or keys;

c) decrypting and re-encrypting, by the intermediate receiver, said key or keys;

d) transmitting said re-encrypted key or keys to the final destination device; and

e) decrypting, by the final destination device, said re-encrypted key or keys, wherein the digital content is once encrypted for protection by the content protector and once decrypted by the final destination device.

2. A method according to claim 1, wherein c) and d) are iterated once or more than once between the intermediate receiver and a further receiver.

3. A method according to claim 1, wherein the key or keys for accessing the digital content are symmetric cryptographic keys.

4. A method according to claim 1, further comprising attaching identification and/or authentication data, to the encrypted and transmitted keys.

5. A method according to claim 4, wherein the attachment of said identification and/or authentication data to the encrypted and transmitted keys is cryptographically secured, and wherein the identification and/or authentication data comprises a signature.

6. A method according to claim 1, further comprising attaching a set of conditions defining the right or rights to the digital content to the encrypted and transmitted keys.

7. A method according to claim 6, wherein the attachment of said set of conditions to the encrypted and transmitted keys is cryptographically secured.

8. A method according to claim 6, wherein said set of conditions defining the right or rights to the digital content are transmitted via one channel and the encrypted keys are transmitted via another channel.

9. A method according to claim 1, wherein the key or keys for the encryption and decryption of the key or keys accessing the digital content are symmetric or asymmetric cryptographic keys.

10. A method according to claim 1, wherein the method is used to distribute a digital movie or parts thereof between a distributor being the content protector a receiver and a projection device being the final destination device.

11. A method according to claim 1, wherein the method is used to distribute a program or parts thereof between a broadcasting union, being the content protector a TV broadcaster being the receiver and a integrated receiver decoder being the final destination device.

12. A storage medium having recorded thereon encrypted program data in a data format able to perform a method comprising:

a) encrypting, by the content protector, a key or keys for accessing said protected digital content;

b) transmitting, from a content protector to an intermediate receiver, said encrypted key or keys;

c) decrypting and re-encrypting, by the intermediate receiver, said key or keys;

d) transmitting said re-encrypted key or keys to a final destination device; and

e) decrypting, by the final destination device, said re-encrypted key or keys, wherein the digital content is once encrypted for protection by the content protector and once decrypted by the final destination device.

13. An intermediary device for use in a multi layered conditional access system for processing encrypted digital data received from a content protector or from an intermediate receiver, wherein the device is able to decrypt and re-encrypt a key or keys for accessing said digital data.

14. The device of claim 13, wherein the device is configured to verify a set of conditions attached to the encrypted key or keys, and wherein the set of conditions define the right or rights to the digital data.

15. A final destination device for use in a multi layered conditional access system for processing encrypted digital data, wherein the final destination device receives re-encrypted data from a receiver, and the final destination device is configured to decrypt the re-encrypted data.

16. A system for processing a protected digital content, comprising:

a) means for encrypting at least one key for accessing said protected digital content, and transmitting said encrypted key;

c) means for receiving, decrypting, and re-encrypting said key encrypted, and transmitting said re-encrypted key; and

e) means for decrypting said re-encrypted key, wherein the digital content is once encrypted for protection by the content protector and once decrypted by a final destination device.