Patent Document ID: 7814564
Application ID: 11326313
Patent Status: 1

Claim One:
1. A method for identifying a participant in production of an unauthorized version of multimedia content through a digital fingerprint embedded in digital data thereof, the method comprising: assigning to a group of a plurality of authorized users of the digital data a corresponding group codeword, said group codeword being shared by said plurality of authorized users of said group thereof, assigning to each of said plurality of authorized users a user codeword, each of said group and user codewords including a respective plurality of symbols selected from a predetermined alphabet of symbols; dividing the digital data into a plurality of host data segments equal in number to said respective plurality of symbols; encoding a fingerprint signal as a concatenation of digital code sequences corresponding to each of said respective plurality of symbols, said fingerprint signal including a respective plurality of fingerprint segments equal in number to said respective plurality of host data segments, each of said fingerprint segments containing at least one of said code sequences corresponding to said group and user codewords; segmenting each of said fingerprint segments into a plurality of subsegments; randomly permuting said subsegments of said fingerprint signal, wherein each said subsegment contains a partial code sequence of a plurality of symbols from the plurality of authorized users' code; embedding said permuted fingerprint signal into the digital data; extracting a test fingerprint signal from a copy of the digital data; segmenting said test fingerprint signal into said plurality of subsegments; applying an inverse permutation to said subsegments of said test fingerprint signal with respect to said permutation of said subsegments of said fingerprint signal; and identifying at least one respective group of said plurality of authorized users the participant belongs to, and identifying the participant as one of said at least one respective identified group of said plurality of authorized users assigned said group codeword determined from said inversely permuted test fingerprint signal.