Abstract: A method for copy protecting a record carrier is disclosed, in which method the copy protected record carriers are provided with a pattern of logical errors which cannot be corrected by the error correcting rules predefined for said record carrier. The pattern of logical errors represents access control information. The logical errors are generated during decoding the bit sequence read from the record carrier. Bit errors may be positioned in the bit sequence so as to counteract de-interleaving which is part of an error decoding process in a reading device and accumulate in error words which are uncorrectable. Also a method for detecting access control information and a retrieval arrangement are disclosed, which retrieval arrangement serves to detect the access control information by selecting at least one error location, but not all error locations on the record carrier, and verifying the presence of an error by reading the selected error location via the reading means.

Abstract: The invention provides a device driver for monitoring and controlling access to data on a computer readable medium. The device driver comprises an interface for access to a device-driver stack for a media drive, a detector for detecting the insertion of a computer readable medium in said media drive, and a monitor for monitoring data transfer from said computer readable medium. The monitor evaluates a behavior characteristic of an application accessing data on said computer readable medium, and indicates when said behavior characteristic fulfills predetermined criteria. A control system is responsive to said monitor for issuing at least one control output when said behavior characteristic fulfills said predetermined criteria. The invention also provides a method of monitoring and controlling access to data on a computer readable medium by means of the device driver.

Abstract: To copy a copy protected DVD (32), and thereby subvert the copy prot-ection technique, a DVD drive (50) is controlled by a disc copying program (54) to access data at a level other than that at the user data level. For example, if it is the data frame (44) which is read, the DVD drive (50) is controlled to write a data frame (12) to a copy disc (52). During the copying process, the program (54) may be arranged to remove sector IDs and error detection codes from the read data frames (44) and to generate new sector IDs and appropriate ID error detection codes for the data frames (12) to be written to the copy disc (52). This circumvents any copy protection which has been incorporated in the identification data in a data frame of the original disc (52).