Audio zero watermarking scheme based on sub band mean energy comparison using DWT-DCT

Digital format of data has become very popular now a days with the advancement of technology. But the problem arises when unauthorized copying and distribution of these digital contents took place. As a result the question of copyright protection came. In order to cope with this situation, the era of Digital Watermarking came where the authorized owner hides some kind of information in an imperceptible way into the digital data. Digital Audio Watermarking is a technique to hide information in a host audio file in such a way that it is imperceptible to the listener. It is used for the copyright protection, tamper proofing of any multimedia file. In this paper a robust and efficient audio zero-watermarking algorithm is introduced. Audio zero-watermarking is an embedding technique in which the watermark does not modify the original audio file as it is hidden into a secret key. In this technique, 1-level DWT and DCT are done on the host audio and then a logical key is generated. Experimental results show that the proposed scheme is efficient and the watermarked signal is indistinguishable from the host audio signal as no modification is done in the original audio. This scheme provides high robustness against the desynchronization attacks and common attacks like cropping, noise addition, re-sampling, re-quantization, lowpass filtering, MP3 compression etc. In order to evaluate the performance of the proposed watermarking method, we have shown the respective BER and Normalized correlation (NC) values.