Browsing School of Engineering, Applied Science and Technology by Author "Abed-Meraim, Karim"
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ItemControlled distortion for high capacity data-in-speech spectrum steganography(Institute of Electrical and Electronics Engineers Inc., 2010) Djebbar, Fatiha; Hamam, Habib; Abed-Meraim, Karim; Guerchi, DrissMethods applied to ensure privacy of digital data became essential in many real life applications. Efficient secrecy can be achieved, at least in part, by implementing steganography techniques. In this paper, we present a technique that limits the impact of high data capacity embedding on the quality of stego wideband speech. Our method uses the energy of each frequency bin component to determine the maximum number of bits that can be confined without inducing any noticeable distortion on the cover speech. To guarantee good quality of stego speech, the embedding in the selected frequency components occurs below a well defined distortion level to limit the impact of the hiding on the stego-speech. The algorithm uses multiple parameters that can be adjusted by the sender to render the steganalysis work more challenging. The objective and subjective results show that this approach is robust to noise addition and maintains a very good quality of the cover signal while achieving high hiding capacity. © 2010 IEEE. ItemDynamic energy based text-in-speech spectrum hiding using speech masking properties(Institute of Electrical and Electronics Engineers Inc., 2010) Djebbar, Fatiha; Abed-Meraim, Karim; Guerchi, Driss; Hamam, HabibIn this paper we present a new method for text-in-speech Fast Fourier Transform (FFT) based steganography. Our method exploits high energetic magnitude frequency components of speech spectrum to hide the secret text. The energy level of each magnitude component is evaluated, and considered only if it is high enough to embed secret data. A frequency maskmg threshold is then calculated for each energetic frequency magnitude component to decide where to embed the secret text. As a result, the initial energy of the cover speech spectrum is slightly modified and the dIstortion error is always kept under the mask. The objective and subjective evaluations show that introducing the energy-based frequency masking 0l?ens new frontiers in text-in-speech steganography since hIgher bit rate text embedding was achieved while obtaining a stego-speech with unnoticeable distortion. © 2010 IEEE. ItemText hiding in high frequency components of speech spectrum(Institute of Electrical and Electronics Engineers Inc., 2010) Djebbar, Fatiha; Guerchi, Driss; Abed-Meraim, Karim; Hamam, HabibBoosted by recent advances in the information technology field, methods applied to ensure privacy of digital data became very important in many real life applications. Efficient secrecy can be achieved at least in part, by implementing steganograhy techniques. In this paper, we propose a new technique to hide text in wideband speech in noise free environment. We opted to work in the Fourier transform domain and hide the digital information within high frequency components. More precisely, our method exploits selected locations from the high-frequencies part of the cover speech to hide the secret text. We better preserve with high fidelity the spectrum shape of the speech carrier by employing an embedding rather than a replacement operation on the secret text. Our simulation results show that this approach maintains the robustness of the cover signal and achieves a higher hiding capacity. © 2010 IEEE.