Abstract: A recordable data storage disc comprises a substrate having a spirally or concentrically shaped groove pattern. A groove depth of the groove pattern is greater than 90 nanometers, and a track pitch provided by the groove pattern is less than 500 nanometers. The data storage disc further comprises a write-once recording layer formed on the groove pattern, and a reflector layer formed on the recording layer opposite the substrate. The groove depth of greater than 90 nanometers allows a thicker coating of dye to be used for the recording layer compared to other recordable data storage discs with a groove pattern with a groove depth of 90 nanometers or less. The thicker coating of dye allows a lower write power, better modulation when reading a data signal from the disc. The groove depth of greater than 90 nanometers may also allow for more precise push-pull tracking.

Abstract: In general, the invention allows for content protection of digital data by intentionally introducing errors introduced within error correction information during the production or generation of an original digital medium, or any authorized copy thereof The errors may be introduced within error correction information corresponding to the stored content, such as a software application, audio or video file, or within a stored “access key” used to access the content. The errors may be introduced, for example, at the time of manufacturing of the medium or when making an authorized copy of digital data. When authenticating digital media, the erroneous error correction information is disregarded and corresponding “raw” uncorrected data is used for authentication purposes.