Voice encryption using a unified hyper-chaotic system

A Chaos-based cryptosystem is a vital method to enhance information protection in communication systems. The previous works have addressed this topic either by using highly complicated algorithms that are difficult to apply in practice or have a few encryption keys. This paper presents a new, highly secure chaos-based secure communication system that combines a conventional cryptography algorithm with two levels of chaotic masking technique. Furthermore, to enhance the security level, we employ the characteristic of a unified hyper-chaotic system to generate three different types of attractors. A Simulink of the stated system is implemented using MATLAB SIMULINK (R2013) to transmit a voice signal. Several testing methods such as power spectral density, spectrogram, histogram analysis, key sensitivity, correlation coefficient, signal to noise ratio (SNR), Percent Residual Deviation (PRD) are carried out to evaluate the quality of the proposed algorithm in several domains, time, frequency, and statistics. The simulation and comparison results demonstrate the high efficiency of the suggested cryptosystem and robustness against various cryptographic attacks.