Research, Voip-based Real-time Covert Communication Model And Synchronization Mechanisms

In recent years, information security research focuses on steganography.At present static carrier such as image and audio is applied to information hiding.Now the internet and stream media became more and more popular, steganography based on the stream media is the research hotspot. In this paper, we studied real-time steganography model for convert communication based on VoIP and synchronization mechanism.And it has good application prospect and provide a new method for security transmission in the internet.In this paper we did some researches on the algorithmic characteristic of G.729a and brought forward an information hiding algorithm based on the position vector in the excitation sequence codebook. Also a noisy resistance model aimed at the vector codebook was presented to analyze the parameter's capability of carrying secrete information. Additionally in order to prove the feasibility of info hiding the transparency of the algorithm was evaluated from subjective feeling. From the experiment it can be concluded that the vector codebook has a strong capability of the noisy resistance and can be an appropriate location for information hiding.An improved steganongraphy-oriented prototype with two pseudo-random sequences is proposed. This stego-prototype is general and can be applied in stegosystem based on VoIP. We prove that the improved stego-prototype accords with theε-secure against passive adversaries condition defined by Cachin. We also give an experimental result with the passive adversary detection that the prototype applied in VoIP results in perfectly security without detection.A real-time steganography prototype for convet communication was achived.The stego instance message was supported in three different carrier of G.711,G.723.1 and G.729a.The feasibility an security in convert communication of the stream media was proved.Stegaongraphy algorithm based on low speed speech and secure analysis anainst passive adversary have common application in information-hiding technology. Keywords:steganography, synchronization, fixed-codebook, G.729...