A hybrid scheme of information hiding incorporating steganography as well as watermarking in the speech signal using Quantization index modulation (QIM)

This paper presents a new approach for digital Speech Steganography and watermarking in the speech signal. In the proposed approach, Quantization index modulation is applied on one of the speech signal feature called as line spectral frequency to indicate the pattern of watermark in each frame of the speech signal. Steganographic data or watermarked information is conveyed through the silence part of the speech signal. The pattern generated using QIM in line spectral frequency (LSF) of the speech gives the information about the existence of steganography or watermarking in the silence part of the speech signal. The blind detection technique is used at the receiver to detect the pattern generated at the transmitter side to identify steganography or authenticity in the speech signal. Various subjective and objective analysis are carried out on a dither modulated speech to evaluate its performance and also the robustness of the same is verified by applying a different types of communication attacks on it. The performance measures are shown in terms of set of tables and graphs. It is observed from the obtained results that, the results of different speech quality assessment parameter as well as the parameters denoting the hiding capacity of each wave file of different speakers are quite good and satisfactory.