Patent ID: 6715122
Filing Date: 2004-03-30
Classification: G11B

Abstract:
A method for preventing the unauthorized replication of an original digital data file having user data comprising a plurality of data samples with error correction code encoded therein, wherein the original digital data file will function properly in a normal reading device and an unauthorized copy is prevented from doing so, the method comprising steps of:(a) substituting a plurality of second data set samples in place of a plurality of the user data samples to generate a combined data set; (b) calculating error correction codes to correct errors in the combined data set; and (c) writing an uncorrectable error to the error correction code for each second data set sample of the combined data set such that the normal reading device will read each uncorrectable error and conceal the corresponding second data set sample while outputting a compensated output sample for the concealed second data set sample, wherein an unauthorized copy of the digital data file will fail to include the uncorrectable errors in the error correction codes so that, when the unauthorized copy of the digital data file is read, the normal reading device will produce an output signal comprising the user data samples with the second data set samples intermingled therein.