Voice-over-ip Chaotic Encryption Algorithm

The advance of the digital signal processing technology and the prevalence of the network communication have brought about a crisis of multimedia security, which triggered an avalanche of attentions either paid by the government or by the general public. Since the multimedia data like image, video and audio have certain intrinsic properties such as high redundancy and bulk capacities, special concerns on operation speed, computational payload and many other security issues have to be made in the construction of the encryption algorithms that would not be taken into account in that of text encryption. In this regards, currently existing cryptological methods are not appropriate for the applications of nowadays multimedia encryption.At the same time, the combination of the cutting-edge chaotic theory and the cryptography has led to the birth of a span-new technology, chaotic cryptology, which has become a novel and effective way to accomplish the task of multimedia security.In this thesis, chaos based IP voice secure transmission technique is studied. Several chaotic encryption methods that incorperated with voice coding are brought forth, which includes an block cipher algorithm jointly using Cat map and Logistic map, two G. 729 based chaotic encryption methods and an ameliorated algorithm improved upon previous two. The security analysises, the emperimental results as well as details on software implementation are reported in the paper.Finally, the thesis is concluded by pointing out some further research directions on the research of IP voice encryption.