Access to encrypted broadcast content

• US 20050100161A1
• Filed: 12/10/2002
• Published: 05/12/2005
• Est. Priority Date: 12/10/2001
• Status: Active Grant

• Current Assignee: Dirk Husemann, Michael Nidd
• Original Assignee: Dirk Husemann, Michael Nidd
• Inventors: Husemann, Dirk, Nidd, Michael
• Granted Patent: US 7,248,694 B2
• Time in Patent Office: Days
• US Class Current: 380/200
• CPC Class Codes: G06Q 20/0855 involving a third party
• CPC Class Codes: H04H 2201/20 digital audio broadcasting [DAB]
• CPC Class Codes: H04H 60/23 using cryptography, e.g. encryption, authentication, key distribution
• CPC Class Codes: H04L 2209/601 Broadcast encryption
• CPC Class Codes: H04L 9/0825 using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates
• CPC Class Codes: H04L 9/083 involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP]
• 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 21/4181 for conditional access
• 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
• 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 21/63775 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 21/8106 involving special audio data, e.g. different tracks for different languages
• 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
• CPC Class Codes: H04N 7/17318 Direct or substantially direct transmission and handling of requests

Abstract

Methods for providing a receiver subsystem with access via a clearing house subsystem to a content item broadcast from a content provider subsystem. A method includes generating the request for access in the receiver subsystem, and employs a content key, a blocking nonce, a public key of a public-private key pair, a public key encrypted content key, and a double encrypted content key. The method may also include, in the receiver subsystem, encrypting the request for access based on the private key of the public-private key pair. Provides apparatus for providing access to a broadcast content item. A receiver subsystem is arranged to generate the request for access. In an example embodiment the receiver subsystem is arranged to encrypt the request for access based on the private key of the public-private key pair. Provides a receiver subsystem, a content provider subsystem, and a clearing house subsystem.

Claims

1. A method for providing a receiver subsystem with access via a clearing house subsystem to a broadcast content item broadcast from a content provider subsystem, the method comprising at least one step taken from a group of steps consisting of:

in the content provider subsystem, encrypting the broadcast content item based on a content key to produce an encrypted content item, generating a blocking nonce corresponding to the content key, transmitting the content key and the blocking nonce to the clearing house subsystem, and transmitting the encrypted content item and the blocking nonce to the receiver subsystem;

in the clearing house subsystem, receiving the content key and the blocking nonce from the content provider subsystem, receiving a public key of a public-private key pair of the receiver subsystem, and, in response to a request for access to the broadcast content item, encrypting the content key based on the public key to produce a public key encrypted content key, encrypting the public key encrypted content key based on the blocking nonce to produce a double encrypted content key, and transmitting the double encrypted content key to the receiver subsystem; and

,

in the receiver subsystem, receiving the double encrypted content key from the clearing house subsystem, receiving the encrypted content item and the blocking nonce from the content provider subsystem, decrypting the double encrypted content key based on the blocking nonce to recover the public key encrypted content key, decrypting the public key encrypted content key based on a private key of the public-private key pair to recover the content key, and decrypting the encrypted content item based on the content key to recover the requested broadcast content item.

2. A method as claimed in claim 1, further comprising generating the request for access in the receiver subsystem.

3. A method as claimed in claim 2, further comprising in the receiver subsystem, encrypting the request for access based on the private key of the public-private key pair.

11. A method as claimed in claim 1, wherein the step of providing is employed in a business to business application.

12. A method as claimed in claim 1, wherein the step of transmitting comprises distributing the double encrypted content keys via a broadcast web site as directories of files, each file containing the content key for a particular receiver subsystem.

13. A method as claimed in claim 1, wherein at least one step involves a financial transaction to facilitate subscriber access to content and/or services carrying an access charge.

14. A method as claimed in claim 1, further comprising providing enhanced security by the receiver subsystem encrypting subsequent requests for content items with the private key for decoding upon receipt by the clearing house subsystem in which a corresponding public key is registered.

15. A method as claimed in claim 1, wherein the step of providing comprises providing a conditional access broadcast system in which a subscriber is integrated into a protection chain.

16. A method as claimed in claim 1, wherein the step of providing comprises operating with a back channel

17. A method as claimed in claim 1, wherein the step of providing comprises employing a smart card reader in the receiver.

18. A method as claimed in claim 1, wherein the step of providing comprises enabling the content provider to operate independently of any third party network providers.

19. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for providing the broadcast content item, said method steps comprising the steps of claim 1.

4. Apparatus for providing access to a broadcast content item, the apparatus comprising at least one element taken from a group of elements consisting of:

a receiver subsystem having a public private key pair;

a content provider subsystem having an first encryption unit for encrypting the broadcast content item based on a content key to produce an encrypted content item, a nonce generator for, generating a blocking nonce corresponding to the content key, and a first transmitter connected to the encryption unit and nonce generator for transmitting the content key, the blocking nonce, and the encrypted content item; and

,

a clearing house subsystem having a first receiver for receiving the content key and the blocking nonce from the content provider subsystem and the public key of the receiver subsystem, a second encryption unit connected to the first receiver for encrypting the content key based on the public key to produce a public key encrypted content key and encrypting the public key encrypted content key based on the blocking nonce to produce a double encrypted content key in response to a request for access to the broadcast content item, and a second transmitter connected to the second encryption unit for transmitting the double encrypted content key to the receiver subsystem;

wherein,

the receiver subsystem further comprises a second receiver for receiving the double encrypted content key from the clearing house subsystem and the encrypted content item and the blocking nonce from the content provider subsystem, and a decryption unit connected to the receiver for decrypting the double encrypted content key based on the blocking nonce to recover the public key encrypted content key, decrypting the public key encrypted content key based on a private key of the public private key pair to recover the content key, and decrypting the encrypted content item based on the content key to recover the requested broadcast content item.

5. Apparatus as claimed in claim 4, wherein the receiver subsystem is arranged to generate the request for access.

6. A method as claimed in claim 5, wherein the receiver subsystem is arranged to encrypt the request for access based on the private key of the public-private key pair.

7. A receiver subsystem of apparatus as claimed in claim 4.

8. A content provider subsystem of apparatus as claimed in claim 4.

9. A clearing house subsystem of apparatus as claimed in claim 4.

10. A Digital Audio Broadcast system comprising apparatus as claimed in claim 4.

20. An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing provision of a receiver subsystem with access via a clearing house subsystem to the broadcast content item broadcast from a content provider subsystem, the computer readable program code means in said article of manufacture comprising computer readable program code means for causing a computer to effect at least one step taken from a group of steps consisting of:

in the content provider subsystem, encrypting the broadcast content item based on a content key to produce an encrypted content item, generating a blocking nonce corresponding to the content key, transmitting the content key and the blocking nonce to the clearing house subsystem, and transmitting the encrypted content item and the blocking nonce to the receiver subsystem;

in the clearing house subsystem, receiving the content key and the blocking nonce from the content provider subsystem, receiving a public key of a public-private key pair of the receiver subsystem, and, in response to a request for access to the broadcast content item, encrypting the content key based on the public key to produce a public key encrypted content key, encrypting the public key encrypted content key based on the blocking nonce to produce a double encrypted content key, and transmitting the double encrypted content key to the receiver subsystem; and

,

in the receiver subsystem, receiving the double encrypted content key from the clearing house subsystem, receiving the encrypted content item and the blocking nonce from the content provider subsystem, decrypting the double encrypted content key based on the blocking nonce to recover the public key encrypted content key, decrypting the public key encrypted content key based on a private key of the public-private key pair to recover the content key, and decrypting the encrypted content item based on the content key to recover the requested broadcast content item.

21. A computer program product comprising a computer usable medium having computer readable program code means embodied therein for causing provision of a broadcast content item, the computer readable program code means in said computer program product comprising computer readable program code means for causing a computer to effect at least one function taken from a group of functions consisting of:

a receiver subsystem having a public private key pair;

a content provider subsystem having an first encryption unit for encrypting the broadcast content item based on a content key to produce an encrypted content item, a nonce generator for generating a blocking nonce corresponding to the content key, and a first transmitter connected to the encryption unit and nonce generator for transmitting the content key, the blocking nonce, and the encrypted content item; and

,

a clearing house subsystem having a first receiver for receiving the content key and the blocking nonce from the content provider subsystem and the public key of the receiver subsystem, a second encryption unit connected to the first receiver for encrypting the content key based on the public key to produce a public key encrypted content key and encrypting the public key encrypted content key based on the blocking nonce to produce a double encrypted content key in response to a request for access to the broadcast content item, and a second transmitter connected to the second encryption unit for transmitting the double encrypted content key to the receiver subsystem;

wherein,

the receiver subsystem further comprises a second receiver for receiving the double encrypted content key from the clearing house subsystem and the encrypted content item and the blocking nonce from the content provider subsystem, and a decryption unit connected to the receiver for decrypting the double encrypted content key based on the blocking nonce to recover the public key encrypted content key, decrypting the public key encrypted content key based on a private key of the public private key pair to recover the content key, and decrypting the encrypted content item based on the content key to recover the requested broadcast content item.