Real-time Covert Communications Channel for Audio Signals
Covert communications channel is considered as a type of secure communications that creates capability to transfer information between entities while hiding the contents of the channel. Multimedia data hiding techniques can be used to establish a covert channel for secret communications within a media carrier. In this paper, a high-rate covert communications channel is developed to exploit an audio stream as a carrier signal using multiple embedding in the Quantization Index Modulation framework. The proposed approach uses multi quantization vectors to increase data transmission rate. The embedding algorithms consider the embedding process as a communications problem, that it uses structured scheme of Multiple Trellis-Coded Quantization jointed with Multiple Trellis-Coded Modulation. Using convolution codes based trellis coding returns a real-time communications, because it can be continuously encoded and decoded. The proposed approach exhibits a high channel capacity due to the increase in data embedding rate without severely increasing in embedding distortion.
Keywords: Hidden communications, Real time communications, quantization index modulation, Embedding Process, Audio Signals communications.
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ABOUT THE AUTHORS
Ashraf Seleym
Faculty of Computers and Information, Cairo University, Cairo, Egypt
Dina Darwish
received the B.Sc. in 2004 and the M.Sc. in 2006 with honors degree from Arab Academy for Science and Technology, Egypt. She received the Ph.D. degree from Cairo University, Egypt, 2009. Her main interests include communications systems, computer networks, internet technology, and multimedia systems. She is assistant professor of communications and computer networks, International Academy for Engineering and Media Science (IAEMS), Egypt, since September 2009.
Ashraf Seleym
Faculty of Computers and Information, Cairo University, Cairo, Egypt
Dina Darwish
received the B.Sc. in 2004 and the M.Sc. in 2006 with honors degree from Arab Academy for Science and Technology, Egypt. She received the Ph.D. degree from Cairo University, Egypt, 2009. Her main interests include communications systems, computer networks, internet technology, and multimedia systems. She is assistant professor of communications and computer networks, International Academy for Engineering and Media Science (IAEMS), Egypt, since September 2009.
