Method and apparatus for protecting copyright of digital recording medium and copyright protected digital recording medium

A copyright protection method to protect a copyright with respect to information to be recorded on a digital recording medium, the copyright protection method comprising:

• encrypting the information to be recorded on the digital recording medium using a cryptosystem;
• recording the information encrypted on the digital recording medium;
• and
• recording a cypher key to decrypt the information encrypted on the digital recording medium so that the cypher key is not allowed to be copied,
• wherein said digital recording medium is an optical disk and said cypher key is recorded only in a BCA preamble of a burst cutting area (BCA) of the optical disk.

A copyright protection method to protect a copyright with respect to information to be recorded on a digital recording medium, the copyright protection method comprising:

• encrypting the information to be recorded on the digital recording medium using a stored cryptosystem, of a plurality of cryptosystems, with the cryptosystem not being recorded on the recording medium;
• recording the information encrypted on the digital recording medium;
• recording a cypher key to decrypt the information encrypted on the digital recording medium so that the cypher key is not allowed to be copied, with the cypher key differentiating the cryptosystem, among the plurality of cryptosystems, as the cryptosystem used to encrypt the encrypted information;
• reading the cypher key from the digital recording medium;
• and
• decrypting the encrypted information recorded on the digital recording medium using the cypher key read and the cryptosystem.

A copyright protection method to protect a copyright with respect to information to be recorded on a digital recording medium, the copyright protection method comprising:

• encrypting the information to be recorded on the digital recording medium using a cryptosystem;
• recording the information encrypted on the digital recording medium;
• and
• recording a cypher key to decrypt the information encrypted on the digital recording medium so that the cypher key is not allowed to be copied,
• wherein said cryptosystem is a modulation method to modulate the information to be recorded using a varied table whose relationship between symbols and codes are varied from a predetermined table, and table identification information representative of the varied table is used as the cypher key.

A digital recording medium, comprising:

• a data recording region, wherein at least a part of information is encrypted using a cryptosystem and recorded in a user/data area of the data recording region;
• and
• a copy disapproval region on which a cypher key to decrypt the encrypted information recorded on the data recording region is recorded,
• wherein said digital recording medium is an optical disk and which comprises a preamble, of a burst cutting area (BCA), with the cypher key being recorded only in the preamble.

A digital recording medium, comprising:

• a data recording region, wherein at least a part of information is encrypted using a cryptosystem and recorded in a user/data area of the data recording region;
• and
• a copy disapproval region on which a cypher key to decrypt the encrypted information recorded on the data recording region is recorded,
• wherein said cryptosystem is a modulation method to modulate the information to be recorded using a varied table whose relationship between symbols and codes are varied from a predetermined table, and the cypher key is table identification information representative of the varied table.

A playback apparatus for a digital recording medium including a data recording region, wherein at least a part of information is encrypted using a cryptosystem, of a plurality of cryptosystems, and recorded in a user/data area of the data recording region, and a copy disapproval region on which a cypher key to decrypt the encrypted information recorded on the data recording region is recorded, the playback apparatus comprising:

• a memory to store the plurality of cryptosystems prior to a reading of the digital recording medium;
• a reader to read the encrypted information and cypher key recorded on the digital recording medium;
• and
• a decrypter to decrypt the encrypted information, recorded on the digital recording medium and read by the reader, using the cryptosystem, with the cypher key differentiating the cryptosystem, among the plurality of cryptosystems, as the cryptosystem used to encrypt the encrypted information.

A digital recording and/or reproducing system, comprising:

• a digital recording medium including a data recording region, wherein at least a part of information is encrypted using a cryptosystem, of a plurality of cryptosystems, and recorded in a user/data area of the data recording region, and a copy disapproval region on which a cypher key necessary to decrypt the encrypted information is recorded, with the cypher key differentiating the cryptosystem, among the plurality of cryptosystems, as the cryptosystem that was used to encrypt the encrypted information;
• a memory to store the plurality of cryptosystems prior to a reading of the digital recording medium;
• a reader to read the encrypted information recorded on the digital recording medium;
• and
• a decrypter to decrypt the encrypted information recorded on the digital recording medium and read by the reader, based on the cypher key read by the reader.

A digital recording and/or reproducing system, comprising:

• a digital recording medium including a data recording region, wherein at least a part of information is encrypted using a cryptosystem, of a plurality of cryptosystems, and recorded in a user/data area of the data recording region, and a copy disapproval region on which a cypher key necessary to decrypt the encrypted information is recorded;
• a memory to store the plurality of cryptosystems;
• a reader to read the encrypted information recorded on the digital recording medium;
• and
• a decrypter to decrypt the encrypted information recorded on the digital recording medium and read by the reader, using the cryptosystem stored in the memory based on a differentiation of the cryptosystem, among the plurality of cryptosystems, by the cypher key as being the cryptosystem used to encrypt the encrypted information,
• wherein said digital recording medium is an optical disk which comprises a burst cutting area (BCA) on which said cypher key is recorded.

A digital recording and/or reproducing system, comprising:

• a digital recording medium including a data recording region, wherein at least a part of information is encrypted using a cryptosystem and recorded in a user/data area of the data recording region, and a copy disapproval region on which a cypher key necessary to decrypt the encrypted information is recorded;
• a memory to store the cryptosystems;
• a reader to read the encrypted information recorded on the digital recording medium;
• and
• a decrypter to decrypt the encrypted information recorded on the digital recording medium and read by the reader, based on the cypher key read by the reader,
• wherein said digital recording medium is an optical disk which comprises a burst cutting area (BCA), with a BCA preamble on which said cypher key is recorded.