An Improved Approach to Secure Digital Audio Using Hybrid Decomposition Technique

Abstract

Unlicensed access to digital audio is found to be very frequent today. Copyright and ownership issues are very common. Obsolete schemes are looking to fail to preserve the ownership of digital audio. A watermark data validates the correct belongingness of an audio file. Inculcation of any data into an audio signal is not always tolerated by audio. In this work, a robust method is proposed based on a hybrid decomposition technique in which discrete wavelet transform (DWT), discrete cosine transform (DCT), and singular value decomposition (SVD) applied to successfully perform watermarking in audio signals. A watermark image of size 16 by 16 pixels is used to inculcate in the digital audio of sampling rate 44.1 kHz. The watermark image is first undergone into a cyclic encoding process in which watermark bits are encoded using the redundant bit. Then the bits are further scrambled using Arnold’s cat map. After the robust encryption, the encrypted watermark bits are embedded into the host audio using hybrid decomposition. The reverse process is applied to extricate the watermark bits. The watermarked audio is tested under various signal processing attacks and the quality of the extracted watermark image is checked using standard parameters. The quality assessment of the watermark image is found satisfactory that declares the robustness of the scheme.