Apparatus and method for reproducing user data

• US 7,178,038 B2
• Filed: 07/16/2002
• Issued: 02/13/2007
• Est. Priority Date: 07/19/2001
• Status: Active Grant

• Current Assignee: Media Content Protection LLC
• 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
• Primary Examiner(s): Barrón; Gilberto
• Assistant Examiner(s): AVERY, JEREMIAH L
• Application Number:
  US10/196,300
• Publication Number:
  US 20030021420A1
• Time in Patent Office: 1,673 Days
• Field of Search: None
• US Class Current: 713/193
• 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

In 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 integrated unit calculates a decryption key using key data read from the recording medium, decrypts the user data read from said recording medium using the calculated decryption key, andre-encrypts the decrypted data using a re-encryption key. The re-encrypted data and the re-encryption key are then transmitted to an application unit for decrypting the re-encrypted data using the re-encryption key and for reproducing the decrypted data.

Claims

1. An apparatus for reproducing user data stored in encrypted form on a recording medium, said apparatus 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. The apparatus as claimed in claim 1, wherein said integrated unit and/or said application unit further comprises:

means for calculating said re-encryption key.

3. The apparatus as claimed in claim 1, wherein said apparatus further comprises;

public key cryptography means for exchanging information on said re-encryption key.

4. The apparatus as claimed in 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. The apparatus as claimed in 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. The apparatus as claimed in claim 1, wherein said recording medium is an optical recording medium, including a CD or a DVD.

7. The apparatus as claimed in claim 1, wherein said integrated unit is an integrated circuit.

9. An integrated unit for use in an apparatus as claimed in claim 1 for reproducing user data stored in encrypted form on a recording medium, said integrated unit 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 subsequent transmission to an application unit for decrypting said re-encrypted data using said re-encryption key and for reproducing the decrypted data.

10. The integrated unit as claimed in claim 9, wherein said integrated unit is an integrated circuit.

8. A method for reproducing user data stored in encrypted form on a recording medium, said method 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;

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

reproducing the decrypted data,

wherein said steps of calculating, decrypting and re-encrypting are carried out in an integrated unit.