Quality-aware GSM speech watermarking

Use of watermarking techniques to provide authentication and tamper proofing of speech in mobile environment is becoming important. However, the current efforts do not allow for user-specifiable quality for the watermarked speech. This paper proposes a watermarking algorithm that allows user-customizable quality for watermarked GSM (Global System for Mobile) speech. Sensitivity (in terms of quality degradation) of each GSM coefficient bits against bit watermark embedding was investigated first, which is then used to select the coefficient bits in a secure manner for watermarking. The proposed algorithm´s execution time requirement was studied to draw conclusions on the real-time usability of the algorithm. The embedding capacity and the quality awareness of the algorithm were also investigated.