A benchmark assessment of the WAUC watermarking audio algorithm

This paper presents a benchmark assessment of the WAUC digital audio watermarking scheme, which relies on MPEG 1 Layer 3 compression to determine where and how the embedded mark must be introduced. The mark is embedded by modifying the magnitude of the spectrum at several frequencies which are chosen according to the difference between the original and the compressed audio content. The main advantage of the scheme is that the perceptual masking of the compressor is implicitly used and, thus, the scheme can be directly tested with different maskings by replacing the compressor. Since repeat coding of the mark is used, a majority voting scheme is applied to improve robustness. The scheme also uses a dual Hamming error correcting code for the embedded mark, which makes it possible to apply it for fingerprinting, achieving robustness against the collusion of two buyers. Several tuning parameters affect the embedding and reconstruction processes, the values of which are chosen according to the tuning guidelines obtained in previous works. In order to illustrate the robustness of the method, the WAUC scheme has been tested against several evaluation profiles, such as the attacks introduced in the Watermark Evaluation Testbed (WET) for audio.