Merging the International Data Encryption Algorithm and Digital Chaotic Scrambler (DCS) to Enhance Audio Security

Voice communication is a daily necessity, and as digital communication channels become increasingly widespread, the importance of voice transmission security is increasing. This paper proposes a robust and secure voice encryption system that combines chaotic systems and traditional cryptography. Specifically, it introduces a Digital Chaotic Scrambler (DCS) based on the Lorenz system to overcome the limitations of the International Data Encryption Algorithm (IDEA) in voice encryption. Incorporating the DCS into the IDEA structure enhances its resilience to cryptographic attacks. The DCS and IDEA's robust mathematical operations create a secure and efficient voice encryption system for real-time applications. Security metrics such as initial condition sensitivity, key sensitivity, and attack resistance quantify the proposed system's performance. Additional analyses, including key space analysis, statistical analysis, Mean Square Error (MSE), Signal-to-Noise Ratio (SNR), Segmental Spectral Signal-to-Noise Ratio (SSSNR), and Cepstral Distance (CD) demonstrate the effectiveness of the approach. Experimental results using audio files of various sizes in WAV format confirm that the suggested algorithms are not vulnerable to brute force or statistical attacks and achieve a higher level of security.