Method for copy protecting a record carrier, copy protected record carrier and means for detecting access control information

A method for detecting access control information, comprising the steps of:

• storing a bit sequence representing information according to predefined formatting and error correcting rules on a record carrier, the information including main information and access control information for controlling the access to the main in information, and in which the bit sequence includes sufficient bit errors to provide correction errors which cannot be corrected by the error correcting rules and which constitute a predefined correction error pattern representing at least part of the access control information, the correction error pattern being defined by correction error locations;
• selecting at least one correction error location, but not all correction error locations, which correction error location(s) should have a correction error according to the predefined correction error pattern;
• and
• verifying the presence of the correction error by reading the selected correction error location and detecting the correction error during error correction.

A recorder for producing an access controlled record carrier, comprising:

• means for providing an image file containing main information;
• means for generating access control in formation for controlling access to the main information;
• means for producing a record carrier depending on the image file and the access control information, including the steps of:
• creating a correctable bit sequence by applying formatting and error correcting rules to the image file;
• modifying the correctable bit sequence according to the access control information to provide correction errors which cannot be corrected by the error correcting rules and which constitute a predefined correction error pattern;
• and
• translating the modified bit sequence into a physical pattern of marks on the record carrier, where the correction errors are stored in the padding area.

A system for programming to produce a recorder, comprising:

• means for providing programmed apparatus for generating access control information for controlling the access to an image file of main information;
• means for providing programmed apparatus for producing a record carrier depending on the image file and the access control information, including:
• means for providing programmed apparatus for creating a bit sequence by applying formatting and error correcting rules to the image file;
• means for providing programmed apparatus for modifying the bit sequence according to the access control information to provide a predefined pattern of correction errors in the bit sequence, the correction errors being errors which cannot be corrected by the error canceling rules;
• and
• means for providing programmed apparatus for translating the modified bit sequence into a physical pattern of marks on the record carrier, where the correction errors are stored in a padding area.

A record carrier comprising:

• a substrate;
• an information area subdivided into addressable sectors and including a padding area;
• a correctable bit sequence representing information according to predefined formatting and error correcting rules, the information including main information and access control information for controlling the access to the main information;
• a license structure comprising instructions for performing the following steps:
• modifying the correctable bit sequence according to the access control information with sufficient bit errors to provide correction errors which cannot be corrected by the error correcting rules and which constitute a predefined correction error pattern;
• translating the modified bit sequence into a physical pattern of marks on the record carrier, where the correction errors are stored in the padding area, in that the padding area includes correction error sectors and correction non-error sectors, the correction error sectors containing the correction errors and the correction non-error sectors containing no errors that can not be corrected by the error correcting rules.