Patent ID: 8051492

Claim:
A method for identifying the source of an unauthorized copy of content, comprising computer instructions being executed on a computer system by a processor that takes the action of: embedding a unique user fingerprint code to into each of a plurality of authorized copies of content; identifying an unknown fingerprint code in an unauthorized copy of said content, said user fingerprint code comprising a binary string of zeros and ones; comparing each member of said unknown fingerprint code to each corresponding member in each of said user fingerprint codes and for each position in said string, determining if both said unknown fingerprint code and said user fingerprint code have ones or zeros in said each position; assigning a non-zero score to each of said user fingerprint codes based on said comparison, wherein said comparing scores both zeros and ones in said unknown fingerprint code; determining which of said scores exceeds a threshold; and identifying as a source of said unauthorized copy at least one user fingerprint code having said score determined to exceed said threshold.