Adaptive Wavelet Packet Based Audio Steganography using Data History

In this paper we present a novel method for digital audio steganography where encrypted covert data is embedded by adaptively modifying wavelet packet coefficients of host audio signal. The major contribution of the proposed scheme is the technique introduced for adaptively modifying the host audio to embed the covert data. The modification of host audio is done by imposing a constraint which forces the modified value to be in the same range as its neighborhood. Due to this constraint the noise introduced due to embedding is very low compared to existing methods. The main advantage with proposed embedding scheme is superior Signal to Noise Ratio (SNR) values, with good hiding capacity and speed. Listening test results also show that distortions in the stego audio is imperceptible from the original audio even with highest hiding capacity. Our method also has zero bit error in recovered data which is one of the most desired features of any steganography technique.