Unauthorized use preventing method for optical disks, optical disk having unauthorized use prevention function, and optical disk apparatus

• US 5,982,886 A
• Filed: 10/11/1996
• Issued: 11/09/1999
• Est. Priority Date: 03/18/1992
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Narumi, Toshikatsu, Suzuki, Hiroshi, Nakahara, Masaru, Nakada, Masahiro, Itami, Satoshi, Utsumi, Kenichi, Nakashima, Kazuo, Naito, Kazunori
• Primary Examiner(s): Barron, Jr., Gilberto
• Application Number:
  US08/730,654
• Time in Patent Office: 1,124 Days
• Field of Search: 380/3, 380/4, 380/5, 369/44.33, 369/47, 360/60
• US Class Current: 705/57
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 21/80 in storage media based on magnetic or optical technology, e.g. disks with sectors preventing unauthorised reproduction or copying of disc-type recordable media G11B20/00
• CPC Class Codes: G06F 2211/007 Encryption, En-/decode, En-/decipher, En-/decypher, Scramble, (De-)compress
• 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 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00557 wherein further management data is encrypted, e.g. sector headers, TOC or the lead-in or lead-out areas
• CPC Class Codes: G11B 20/00615 said format change concerning the logical format of the recording medium, e.g. the structure of sectors, blocks, or frames
• CPC Class Codes: G11B 20/0092 involving measures which are linked to media defects or read/write errors
• CPC Class Codes: G11B 20/00927 wherein said defects or errors are generated on purpose, e.g. intended scratches
• CPC Class Codes: G11B 20/00949 said intentional errors occurring due to bad sectors, which are either physically destroyed or which are declared defective in the defect management information
• CPC Class Codes: G11B 2020/1259 with ROM/RAM areas
• CPC Class Codes: G11B 23/284 on the record carrier
• CPC Class Codes: G11B 7/0037 with discs

Abstract

In a method for preventing unauthorized use of a recording medium having a user accessible area and a user inaccessible area, first information is read from the user inaccessible area of the recording medium. The first information is compared with second information concerning a true recording medium (lawfully produced copy). It is then concluded that the recording medium is the true recording medium when the first information corresponds to the second information.

Claims

1. An optical apparatus for reproducing an information from an area of an optical medium and for communicating the reproduced information with a host controller, the optical medium being attachable to the optical apparatus, said apparatus comprising:

first means for accessing the area of the optical medium;

second means for determining if a read-only-area storing an information not to be copied in an attached optical medium and to be used in a host controller, is present at a predetermined area of the optical medium, wherein said second means includes a comparator for comparing between a storage capacity of the optical medium with a true storage capacity thereof; and

means for preventing accessing the predetermined area of the optical medium by said first means when it is determined by said second means that the read-only-area in the attached optical medium is not presented at the predetermined area of the optical medium.

2. An optical apparatus according to claim 1, wherein the information stored in the read-only-area of the optical medium comprises an operational system software used in the host controller.

3. An optical apparatus for reproducing an information from an area of an optical medium and for communicating the reproduced information with a host controller, the optical medium being attachable to the optical apparatus and having a user accessible area and a user inaccessible area, the user accessible area having a plurality of sectors, said apparatus comprising:

first means for reading predetermined information stored in the user inaccessible area of the recording medium, said predetermined information representing a number of sectors for the user accessible area;

second means for determining a maximum number of sectors for a rewritable area in the user accessible area of an optical medium attached to the optical apparatus; and

third means for concluding that the recording medium is the true recording medium when the predetermined information matches the determined number of sectors for the attached optical medium.

4. A method for reproducing an information from an area of an optical medium and for communicating the reproduced information with a host controller, the optical medium being attachable to the optical apparatus, said method comprising the steps of:

accessing the area of the optical medium;

determining if a read-only-area storing an information not to be copied in an attached optical medium and to be used in a host controller, is present at a predetermined area of the optical medium, wherein the step of determining includes the step of comparing between a storage capacity of the optical medium with a time storage capacity thereof; and

preventing accessing the predetermined area of the optical medium by said first means when it is determined by said second means that the read-only-area in the attached optical medium is not presented at the predetermined area of the optical medium.

5. The method according to claim 4, wherein the information stored in the read-only-area of the optical medium comprises an operational system software used in the host controller.

6. A method for reproducing an information from an area of an optical medium and for communicating the reproduced information with a host controller, the optical medium being attachable to the optical apparatus and having a user accessible area and a user inaccessible area, the user accessible area having a plurality of sectors, said method comprising the steps of:

reading predetermined information stored in the user inaccessible area of the recording medium, said predetermined information representing a number of sectors for the user accessible area;

determining a maximum number of sectors for a rewritable area in the user accessible area of an optical medium attached to the optical apparatus; and

concluding that the recording medium is the true recording medium when the predetermined information matches the determined number of sectors for the attached optical medium.