On Tuesdays the USPTO issues new patents. Both of today's Spotlight Patents address various aspects of copy protection. Assigned to Macrovision, the first patent concerns techniques for ensuring the copy protection of digital data. Assigned to Philips, the second patent concerns techniques for copy protection of information.
7,340,778, "Method and apparatus for ensuring the copy protection of digital data," assigned to Macrovision.
When digital data is to be copy protected at a processing station, for example, prior to its encoding and recording onto an optical disc, it is necessary to control a compliant encoder to utilise copy protection files to perform the copy protection routine. To ensure that the digital data is reliably copy protected, predetermined noise signals are incorporated into the digital data and the processing steps which add the copy protection are additionally caused to remove the noise signals. By this means, if the digital data is not copy protected, the noise signals remain. This enables non-copy protected digital data to be readily identified and ensures that it is effectively unusable to a consumer.
7,340,152, "Method and system of copy protection of information," assigned to Philips.
The invention relates to a method of copy-protection of information stored on an information carrying medium. The method allows a reading device (e.g. a DVD drive) and an application device (e.g. an MPEG decoder) to exchange copy-protection information regarding the information carrying medium (e.g. an optical record carrier like a CD or DVD) and the content on that medium. The method is cryptographically secure, taking into account the situation where reading device and application device are connected to an open bus in a personal computer. In view of the high-volume nature of the drive, the method can be implemented cheaply. The inventive method is robust against a so-called man-in-the-middle attack.The invention relates also to a method of exchanging copy-protection information, to a copy-protection system and to devices for carrying out these methods, in particular a reading device, an application device and a device for playback and/or recording of information.