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Optical disc for a master key, and a method and apparatus for optical-disc information management which inhibit and permit reproduction of main information from an illegal copy disc by using physical and logical security information

  • US 5,809,545 A
  • Filed: 09/12/1995
  • Issued: 09/15/1998
  • Est. Priority Date: 09/30/1994
  • Status: Expired due to Fees
First Claim
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1. A key optical disc having a key for managing a legitimate disc on which main information is recorded, on which physical security information is physically recorded, and on which logical security information is logically recorded, the key optical disc physically storing first security information and logically storing second security information, the first security information being equal to the physical security information physically recorded on the legitimate disc, the second security information being equal to the logical security information logically recorded on the legitimate disc;

  • the key optical disc being used in a method comprising the steps of;

    a) detecting presence and absence of security information physically recorded on a first optical disc being one of the key optical disc and a master key optical disc;

    b) when the presence of the security information physically recorded on the first optical disc is detected by the step a), deciding that the first optical disc is one of a legitimate key optical disc and a legitimate master key optical disc;

    c) detecting security information logically recorded on the first optical disc;

    d) storing the security information detected by the step c);

    e) deciding whether or not the security information stored by the step d) agrees with specified security information corresponding to the legitimate master key optical disc;

    f) permitting reproduction of information from a second optical disc to be checked when the step e) decides that the security information stored by the step d) agrees with the specified security information;

    g) detecting security information logically recorded on the second optical disc when the step e) decides that the security information stored by the step d) does not agree with the specified security information;

    h) deciding whether or not the security information stored by the step d) and the security information detected by the step g) agree with each other;

    i) permitting reproduction of other information from the second optical disc when the step h) decides that the security information stored by the step d) and the security information detected by the step g) agree with each other; and

    j) inhibiting reproduction of other information from the second optical disc when the step h) decides that the security information stored by the step d) and the security information detected by the step g) do not agree with each other.

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