Apparatus and method for reproducing user data

• US 20030021420A1
• Filed: 07/16/2002
• Published: 01/30/2003
• Est. Priority Date: 07/19/2001
• 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: Kamperman, Franciscus Lucas Antonius Johannes, Linnartz, Johan Paul Marie Gerard, Staring, Antonius Adriaan Maria
• Granted Patent: US 7,178,038 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 20/00173 wherein the origin of the content is checked, e.g. determining whether the content has originally been retrieved from a legal disc copy or another trusted source
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00253 wherein the key is stored on the record carrier
• CPC Class Codes: G11B 20/00275 the key being stored on a chip attached to the record carrier
• CPC Class Codes: G11B 20/00449 content scrambling system [CSS]
• CPC Class Codes: G11B 20/00478 wherein contents are decrypted and re-encrypted with a different key when being copied from/to a record carrier
• CPC Class Codes: G11B 20/00492 wherein content or user data is encrypted

Abstract

The invention relates to an apparatus and a method for reproducing user data stored in encrypted form on a recording medium. In order to provide a higher level of protection against hacking of user data and, in particular, of decryption keys, which are used for encrypting said user data and which are also stored on the recording medium, an apparatus is proposed according to the invention, comprising:

means for reading user data and key data from said recording medium,

an integrated unit including

means for calculating a decryption key using said key data,

means for decrypting user data read from said recording medium using said calculated decryption key, and

means for re-encrypting said decrypted data using a re-encryption key,

means for transmitting said re-encrypted data from said integrated unit to an application unit, and

an application unit for decrypting said re-encrypted data using said re-encryption key and for reproducing the decrypted data.

Claims

1. Apparatus for reproducing user data stored in encrypted form on a recording medium, comprising:

means for reading user data and key data from said recording medium,

an integrated unit including

means for calculating a decryption key using said key data,

means for decrypting user data read from said recording medium using said calculated decryption key, and

means for re-encrypting said decrypted data using a re-encryption key,

means for transmitting said re-encrypted data from said integrated unit to an application unit, and

an application unit for decrypting said re-encrypted data using said re-encryption key and for reproducing the decrypted data.

2. Apparatus according to claim 1, wherein said integrated unit and/or said application unit comprises means for calculating said re-encryption key.

3. Apparatus according to claim 1, further comprising public key cryptography means for exchanging information on said re-encryption key.

4. Apparatus according to claim 3, wherein said public key cryptography means are employed to set up a secure authenticated channel for transmitting said re-encryption key from said integrated unit to said application unit.

5. Apparatus according to claim 1, wherein said integrated unit is included in a drive unit for reading recording media and wherein said drive unit and said application unit are included in a computer.

6. Apparatus according to claim 1, wherein said recording medium is an optical recording medium, in particular a CD or a DVD.

7. Apparatus according to claim 1, wherein said integrated unit is an integrated circuit.

9. Integrated unit for use in an apparatus according to claim 1 for reproducing user data stored in encrypted form on a recording medium, comprising:

means for calculating a decryption key using key data read from said recording medium,

means for decrypting user data read from said recording medium using said calculated decryption key, and

means for re-encrypting said decrypted data using a re-encryption key to obtain re-encrypted data for being transmitted to an application unit for decrypting said re-encrypted data using said re-encryption key and for reproducing the decrypted data.

10. Integrated unit according to claim 9, wherein said integrated unit is an integrated circuit.

8. Method for reproducing user data stored in encrypted form on a recording medium, comprising the steps of:

reading user data and key data from said recording medium,

calculating a decryption key using said key data,

decrypting user data read from said recording medium using said calculated decryption key,

re-encrypting said decrypted data using a re-encryption key, wherein said calculation step, said decryption step and said re-encryption step are carried out in an integrated unit,

transmitting said re-encrypted data from said integrated unit to an application unit,

decrypting said re-encrypted data using said re-encryption key in said application unit, and

reproducing the decrypted data.