Anonymous fingerprinting with robust QIM watermarking techniques
EURASIP Journal on Information Security
Hyperbolic RDM for nonlinear valumetric distortions
IEEE Transactions on Information Forensics and Security
On estimation accuracy of desynchronization attack channel parameters
IEEE Transactions on Information Forensics and Security
Combating desynchronization attacks on blind watermarking systems: a message passing approach
ICIP'09 Proceedings of the 16th IEEE international conference on Image processing
High-rate data-hiding robust to linear filtering for colored hosts
EURASIP Journal on Information Security
An improved sample projection approach for image watermarking
Digital Signal Processing
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In this paper we propose a maximum likelihood technique to combat amplitude scaling attacks within a quantization-based watermarking context. We concentrate on operations that are common in many applications and at the same time devastating to this class of watermarking schemes, namely, amplitude scaling in combination with additive noise. First we derive the probability density function of the watermarked and attacked data in the absence of subtractive dither. Next we extend these models to incorporate subtractive dither in the encoder. The dither sequence is primarily used for security purposes, and the dither is assumed to be known also to the decoder. We design the dither signal statistics such that an attacker having no knowledge of the dither cannot decode the watermark. Using an approximation of the probability density function in the presence of subtractive dither, we derive a maximum likelihood procedure for estimating amplitude scaling factors. Experiments are performed with synthetic and real audio signals, showing the feasibility of the proposed approach under realistic conditions