Secret audio watermarking using empirical mode decomposition and chaotic map

Digital watermarking has been discussed in the literature for decades. In business perspective, it is important as a potential method for copy right protection, proof of ownership broadcast monitoring etc. In academic perspective, it is an interesting research problem. Audio watermarking is the most challenging of all as Human Auditory System is sensitive to even a very small change to the original audio. Other than imperceptibility of the signal, capacity and robustness are important too. Empirical mode decomposition is the latest revolutionary concept in audio watermarking. In this paper we present a robust audio watermarking scheme which ensures imperceptibility, robustness and high payload capacity. To prevent un-authorized third parties from removing the watermark, we make use of Tinkerbell chaotic map to generate random secret keys and watermark is embedded following the keys. Multiple keys are used to ensure efficient distribution of the watermark to prevent cropping attacks and enable watermark correction and synchronization with receiver. The experimental results show that the method is robust against re-sampling, cropping, re-quantization, AWGN attacks.