Method and apparatus for decrypting encrypted data stored on a record carrier

• US 20020168070A1
• Filed: 05/07/2002
• Published: 11/14/2002
• Est. Priority Date: 05/09/2001
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Bernsen, Johannes Arnoldus Cornelis
• Granted Patent: US 7,209,562 B2
• Time in Patent Office: Days
• US Class Current: 380/277
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/00152 involving a password
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00369 wherein a first key, which is usually stored on a hidden channel, e.g. in the lead-in of a BD-R, unlocks a key locker containing a second
• CPC Class Codes: G11B 20/00586 said format change concerning the physical format of the recording medium

Abstract

The invention relates to a method for decrypting encrypted data stored on a record carrier, to a corresponding method for encrypting data and to corresponding apparatuses. In order to provide a high level of protection for data stored on a record carrier and to prevent that data stored on different record carriers can be decrypted after a decryption algorithm has become known the method for decrypting encrypted data according to the invention comprises the following steps:

a) generating a decryption key (DK) using a unique carrier identifier (UDI) associated with said record carrier, a hidden key (HK) stored in a hidden channel on said record carrier and a password key (PK), and

b) decrypting said encrypted data stored on said record carrier using said generated decryption key (DK).

Claims

1. A method for decrypting encrypted data stored on a record carrier, comprising the steps of:

a) generating a decryption key (DK) using a unique carrier identifier (UDI) associated with said record carrier, a hidden key (HK) stored in a hidden channel on said record carrier and a password key (PK), and

b) decrypting said encrypted data stored on said record carrier using said generated decryption key (DK).

2. A method according to claim 1, characterized in that said password key (PK) is provided, in particular sold, by a password key provider, in particular the owner or publisher of said encrypted data.

3. A method according to claim 1, characterized in that said generated decryption key (DK) is first used to decrypt an encrypted secondary decryption key (AK), in particular to decrypt an asset key from a key locker (KL), and that thereafter the secondary decryption key (AK), in particular the asset key, is used to decrypting said encrypted data stored on said record carrier.

4. Apparatus for decrypting encrypted data stored on a record carrier, comprising:

a) key generating means for generating a decryption key (DK) using a unique carrier identifier (UDI) associated with said record carrier, a hidden key (HK) stored in a hidden channel on said record carrier and a password key (PK), and

b) decryption means for decrypting said encrypted data stored on said record carrier using said generated decryption key (DK).

5. Reproduction apparatus for reproducing data stored on a record carrier, in particular disc player apparatus, comprising an apparatus for decrypting according to claim 4.

6. Record carrier for storing data in encrypted form, comprising a unique carrier identifier (UDI) associated with said record carrier and a hidden key (HK) stored in a hidden channel on said record carrier,

wherein said unique carrier identifier (UDI) and said hidden key (HK) are used together with a password key (PK) for generating a decryption key (DK), said generated decryption key (DK) being used for decrypting said encrypted data stored on said record carrier.

7. A method for encrypting data to be stored on a record carrier, comprising the steps of:

a) generating a decryption key (DK) using a unique carrier identifier (UDI) to be associated with said record carrier, a hidden key (HK) to be stored in a hidden channel on said record carrier and a password key (PK), and

b) encrypting said data to be stored on said record carrier using said generated decryption key (DK).

8. Apparatus for encrypting data to be stored on a record carrier, comprising:

a) key generating means for generating a decryption key (DK) using a unique carrier identifier (UDI) to be associated with said record carrier, a hidden key (HK) to be stored in a hidden channel on said record carrier and a password key (PK), and

b) encryption means for encrypting said data to be stored on said record carrier using said generated decryption key (DK).