SECURITY IN SPEECH COMMUNICATION SYSTEMS

Abstract

In recent years there has been an increased interest in cryptographic techniques due to publicity and the impact of recent technological advances such as LSI/VLSI , microprocessors and programmable signal processor chips. In this thesis we are interested in security of voice communication . A new technique in speech encryption is proposed. This technique is based on masking the amplitudes and the locations of the vocal tract speech parameters that are estimated according to an assumed model . Two different algorithms are proposed . This technique is applied on the cepstrum as well as on the LPC coefficients. Real speech is used to test and evaluate the performance of the proposed secure system .