Collusion Resistant Fingerprinting In DCT Domain

Digital fingerprinting is a technique for identifying users who use multimedia content for unintended purposes, such as redistribution. These fingerprints are typically embedded into the content using watermarking techniques that are designed to be robust to a variety of attacks. A cost-effective attack against such digital fingerprints is collusion, where several differently marked copies of the same content are combined to disrupt the underlying fingerprints. Anti-Collusion Codes (ACCs) are employed to design the fingerprints, which can accommodate more users than orthogonal modulation based fingerprints with the same amount of signals. The selected DCT coefficients of the original image are quantized according to fingerprints; quantization table is employed to improve the ability of anti-compression. Blind fingerprint detection scheme has larger capacity and is more efficient than the existing algorithms. Keywords— Fingerprinting, Collusion attack,