Location dependent key for decrypting copy protected material on a recording medium

A method of encrypting information to generate encrypted data and recording the encrypted data onto a recording medium, comprising the steps of:

• generating an encryption key based on key data which is recorded to predetermined regions on the same surface as the encrypted data and determined from said recording medium yet is not part of said encrypted data;
• and
• encrypting the information based on said encryption key;
• wherein said key data is random data from a source different than that of said encrypted data which has been inserted in-between said encrypted data at predetermined positions.

An apparatus for encrypting information to generate encrypted data and recording the encrypted data onto a recording medium, comprising:

• means for generating an encryption key based on key data which is recorded to predetermined regions on the same surface as the encrypted data and determined from said recording medium yet is not part of said encrypted data;
• and
• means for encrypting the information based on said encryption key;
• wherein said key data is random data from a source different than that of said encrypted data which has been inserted in-between said encrypted data at predetermined positions.

A method of decrypting encrypted data that has been recorded on a recording medium, comprising the steps of:

• reproducing a first file from said recording medium, said first file containing said encrypted data, wherein said encrypted data has been encrypted by an encryption key and said encryption key is based on random data from a source different than that of the encrypted data and which has been recorded to predetermined regions on the same surface as the encrypted data and inserted in-between said encrypted data yet is not part of said encrypted data;
• reproducing a second file containing data indicative of a predetermined portion of said random data which has been recorded to and inserted into said encrypted data;
• detecting random data within said encrypted data according to said second file;
• generating a decryption key based on said detected random data;
• and
• decrypting said encrypted data of said reproduced first file by using said decryption key.

A method of decrypting encrypted data that has been recorded on a recording medium, comprising the steps of:

• reproducing a first file from said recording medium, said first file which was recorded to predetermined regions on the same surface as the encrypted data on said recording medium and containing said encrypted data, wherein said encrypted data has been encrypted by an encryption key and said encryption key is based on random data from a source different than that of said encrypted data and selected from a predetermined portion of a random file;
• reproducing said random file from said recording medium;
• reproducing a second file from said recording medium, said second file containing data indicative of said predetermined portion of said random file;
• generating a decryption key based on said random data as obtained from said random file according to said second file;
• and
• decrypting said encrypted data of said reproduced first file by using said decryption key.

An apparatus for decrypting encrypted data that has been recorded on a recording medium, comprising:

• means for reproducing a first file from said recording medium, said first file containing said encrypted data, wherein said encrypted data has been encrypted by an encryption key and said encryption key is based on random data from a source different than that of said encrypted data and which has been recorded on one or more predetermined regions on the same surface as the encrypted data on said recording medium and which is not encrypted and which is inserted in-between said encrypted data yet is not part of said encrypted data;
• and for reproducing a second file containing data indicative of a predetermined portion of said random data which has been inserted into said encrypted data;
• means for detecting random data within said encrypted data according to said second file;
• means for generating a decryption key based on said detected random data;
• and
• means for decrypting said encrypted data of said reproduced first file by using said decryption key.

An apparatus for decrypting encrypted data that has been recorded on a recording medium, comprising:

• means for reproducing a first file from said recording medium, said first file containing said encrypted data, wherein said encrypted data has been encrypted by an encryption key and said encryption key is based on random data from a source different than that of said encrypted data and recorded on said recording medium on one or more predetermined regions on the same surface as the encrypted data and which is not encrypted and which is selected from a predetermined portion of a random file;
• for reproducing said random file from said recording medium;
• and for reproducing a second file from said recording medium, said second file containing data indicative of said predetermined portion of said random file;
• means for generating a decryption key based on said random data as obtained from said random file according to said second file;
• and
• means for decrypting said encrypted data of said reproduced first file by using said decryption key.