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Description:
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Digital fingerprinting is a method by which a copyright owner can uniquely
embed a buyer -dependent , inconspicuous serial number (representing the fingerprint )
into every copy of digital data that is legally sold . The buyer of a legal copy is
then deterred from distributing further copies , because the unique fingerprint can be
used to trace back the origin of the piracy . The major challenge in fingerprinting is
collusion , an attack in which a coalition of pirates compare several of their uniquely
fingerprinted copies for the purpose of detecting and removing the fingerprints .
The objectives of this work are two -fold . First , we investigate the need for robustness
against large coalitions of pirates by introducing the concept of a malicious
distributor that has been overlooked in prior work . A novel fingerprinting code that
has superior codeword length in comparison to existing work under this novel malicious
distributor scenario is developed . In addition , ideas presented in the proposed
fingerprinting design can easily be applied to existing fingerprinting schemes , making
them more robust to collusion attacks .
Second , a new framework termed Joint Source Fingerprinting that integrates the
processes of watermarking and codebook design is introduced . The need for this new
paradigm is motivated by the fact that existing fingerprinting methods result in a
perceptually undistorted multimedia after collusion is applied . In contrast , the new
paradigm equates the process of collusion amongst a coalition of pirates , to degrading
the perceptual characteristics , and hence commercial value of the multimedia in question .
Thus by enforcing that the process of collusion diminishes the commercial value
of the content , the pirates are deterred from attacking the fingerprints . A fingerprinting
algorithm for video as well as an efficient means of broadcasting or distributing
fingerprinted video is also presented . Simulation results are provided to verify our
theoretical and empirical observations . |