Robust Watermarking of Audio with Blind Self-Authentication

In this paper robust audio watermarking based on chirp signal is proposed which also includes capability of blind self-authentication. Watermark sequence is extracted from the original audio signal based on sub-bands energy obtained by using wavelet decomposition. The watermarking scheme is such that the watermark sequence remains unchanged for the original and watermarked audio. This enables two independent extraction processes for this sequence. A total match in the sequence extracted by the two procedures ensures the authenticity of audio data and any mismatch indicates tampering. Different simulated attacks were carried out on the watermarked audio and in all the cases tampering was detected by the proposed technique. The test audio signals were selected from the Speech Quality Assessment Material (SQAM) for embedding watermark. The scheme was found to be robust for attacks such as up-sampling, down-sampling, scaling, filtering and additive noise. Key-words— Audio Watermarking Chirps, Robust Watermarking, Self-Authentication, Wavelet Transform.