Voice Encryption Algorithm And Its Application In Network Communication Systems Research

With the great development of audio compression technology and the popularity ofInternet, VoIP technology becomes more and more popular. Meanwhile, when the contentsof audio concern national secret, commercial secret or personal privacy, they may need tobe transmitted with the protection of encryption. Differing from text-data, audio data isenormous, highly redundant and often processed in real-time.Therefore, traditionalencryption algorithms are not appropriate for audio-data.In this thesis, chaos based IP voice secure transmission technique is studied. Thedetailed analysis on emergence of several kinds of chaotic pseudo-random sequence isintroduced at first, and then chaotic encryption algorithms are summarized and discussedfrom the pointview of chaotic stream cipher and chaotic block cipher. Furthermore, a blockcipher algorithm based on standard chaotic map is proposed. Experimental results havedemonstrated that the algorithm has a large space of the key, and can withstand severalattacks like known-plaintext attack and chosen-plaintext attack. Compared with DESalgorithm, the algorithm has a high speed.Moreover, the network communication system of speech encryption based on LAN isdesigned and implemented, in which two optional encryption algorithms are integrated.The system has the function of recording and playing audio, compression, encryption andtransmitting audio on LAN in real-time.