Patent ID: 7870390

Claim:
A method of authentication of candidate data comprising: sampling, using an analog-to-digital (A/D) converter, original signals representing a work using an uneven sampling rate to produce unevenly sampled original signal data; comparing, using a mean square difference (MSD) unit, the unevenly sampled original signal data with the candidate data for a degree of match; and determining whether the candidate data is authentic based on the degree of match wherein the determining step comprises checking whether the candidate data contains a correct watermark present in the candidate data only if the candidate data is authentic and was created using the same uneven sampling rate used in the sampling step by examining the degree of match as represented by a mean square difference (MSD) produced by the mean square difference (MSD) unit, and wherein the candidate data is determined to be authentic if the correct watermark is found to be present in the candidate data as indicated by the mean square difference (MSD) being small.