METHOD OF CHECKING VERSION NUMBER OF ENCRYPTION INFORMATION, AND OPTICAL DISC PLAYBACK DEVICE

• US 20090327359A1
• Filed: 04/14/2009
• Published: 12/31/2009
• Est. Priority Date: 06/30/2008
• Status: Abandoned Application

• Current Assignee: Hitachi-Lg Data Storage Incorporated (Hitachi, Ltd.)
• Original Assignee: Hitachi-Lg Data Storage Incorporated (Hitachi, Ltd.)
• Inventors: AOYAMA, Shohei
• Application Number:
  US12/423,580
• Publication Number:
  US 20090327359A1
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 20/00166 involving measures which result in a restriction to authorised contents recorded on or reproduced from a record carrier, e.g. music or software
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 2220/2541 Blu-ray discs; Blue laser DVR discs
• CPC Class Codes: H04L 2209/605 Copy protection
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying

Abstract

In the case of a BD or the like, when encryption information used for copyright protection is updated, the version number of defective encryption information is stored into an area of a commercial medium other than the content recording area, and the user is prompted to update to a newer version number.

According to an embodiment of the present invention, the version number of encryption information on the device being used can be checked easily by the user by means of an external command. If this is a defect information version number, playback is not performed, and a display that prompts updating of the encryption information is made as required.

Claims

1. A method of checking version number of encryption information in a device that plays back encrypted recorded content containing video and audio from an optical disc recording medium that records the encrypted recorded content, comprising the steps of:

storing version number of the encryption information into a memory;

reading the version number of the encryption information stored in the memory from the memory, in response to a command from outside of the device; and

notifying a user of the read version number.

2. The method of checking version number of encryption information according to claim 1, further comprising the steps of:

reading version number of defective encryption information from the optical disc recording medium, when the optical disc recording medium is loaded into the device;

playing back the encrypted recorded content from the optical disc recording medium, and decrypting encryption;

comparing the version number of the defective encryption information, with the version number stored in the memory; and

determining whether or not to permit operation of the playing back and decrypting step, on the basis of a comparison result in the comparing step.

3. An optical disc playback device that plays back encrypted recorded content containing video and audio from an optical disc recording medium that records the encrypted recorded content, comprising:

a playback and decryption unit that plays back the encrypted recorded content from the optical disc recording medium, and decrypts encryption by using encryption information;

a storage unit that stores version number of the encryption information;

a version-number-information playback unit that plays back, from the optical disc recording medium, version number information of decryption information that is defective in decrypting encryption during playback;

a control unit that compares version number of encryption information as an output of the version-number-information playback unit, with the version number stored in the storage unit to determine whether or not to permit operation of the playback and decryption unit; and

a display creating unit that displays the version number stored in the storage unit.