An adaptive fragile audio watermarking based on MDFT

To modify DFT transform and make it belong to unitary transform, the conception of MDFT(Modified Discrete Fourier Transform) is proposed. At the same time, an adaptive digital audio blind detection fragile watermarking algorithm based on MDFT is proposed. Firstly, the original audio signal was divided into several audio frames, and then to choose the frames by using the pseudorandom number, to make MDFT. Secondly, the watermark bits were embedded into MDFT the (N/2)^th coefficients, the watermarking strong was adaptive to signal energy. The watermarking could be extracted without the original audio signal and the algorithm realized watermarking blind detection. The chaos and the pseudorandom number encryption techniques were used in the algorithm and it had got good security. Experimental results demonstrated the algorithm was fragile and imperceptible.