Secured and Imperceptible Data Transmission Through Digital Audio Signal with Reduced Internal Noise

The work proposed in this paper aims at two major concerns of wireless transmission, which are security and imperceptibility of the transmitting data. This method uses a digital audio signal as carrier for the actual message data to be transmitted in a concealed form and has two complementary parts, insertion of payload in a source audio signal at the sender end and retrieval of payload at the receiver end. To enhance security of the system, three fold measure has been taken to safeguard the hidden data from any potential hacking attempt. These are, (1) insertion of payload in transformed domain based on DFT instead of time domain, (2) use of pseudo-random bit positions for insertion and (3) using a common secret key by both sending and receiving parties. Imperceptibility of the transmitting data is also emphasized by reducing the internal noise impact within the carrier audio signal at the time of insertion. Furthermore, the integrity and authenticity of the retrieved message is verified at the receiving end. The proposed method has been thoroughly examined by various performance metrics in different scenarios, which prove its effectiveness.