Collusion resistant fingerprinting
Digital watermarking is used to carry information by embedding information into the cover data in a perceptually visible or non visible manner. In today's sea of digital information, there are many problems associated like identi cation of the owner of content, and detection of authorized content receivers. Digital ngerprinting, one of the application of watermarking, is one way to detect authorized content receivers from illegally redistributed media. One powerful scheme to broke digital ngerprint scenario is `collusion attack' in which users share information to remove their embed- ded ngerprint. In this research work, we have proposed a ngerprint technique that is robust against average collusion attack and has capability to trace colluders for images. Independent ngerprints are randomly generated using independent and identically distributed (IID) Gaussian source. We proposed two schemes. In rst scheme, n- gerprints were embedded using additive embedding rule and spread spectrum (SS) technique. This scheme is based on embedding ngerprint in di erent block of discrete cosine transformation (DCT). In second, ngerprints were embedded in independent components (ICs) generated by applying independent component analysis (ICA) on cover image. In both schemes, we used non-blind watermarking and correlation based detector. The result shows that the schemes are robust against average collusion at- tack.
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