Design and Implementation Voice Scrambling Model Based on Hybrid Chaotic Signals

Abstract

One of the most common theories used in cryptography is chaos theory, as it has sufficient encryption properties. Such properties can be used to analyse diffusion and confusion processes, which is one of cryptography's key features; a speech scrambling is an important tool in wireless communication systems for enhancing data security. The main target is achieving security to resist malicious eavesdroppers and attacks. This paper presents a speech scrambling model using three various chaotic maps/flows (standard map SM, Unified system US and Chen system CS). The use of the chaotic keys in scrambling techniques are to enhance the transmitted data security, which is strong over the effects of AWGN. Five different tests were included in the evaluation measures: cepstral distance dCD, Linear predict coding distance dLPC, Mean Square Error MSE, Entropy H, and Correlation Factor Rc. The important criteria are residual intelligibility of speech signal between the (original and scrambling/descrambling signal) for the proposed models. The results are good enough to protect the encryption signal of the brute force attack, and when applying a model, the results are being evaluated. The offered model was carried out using SIMULINK (R2018b) by using MATLAB.