An enhanced logistic chaotic map based tweakable speech encryption algorithm

Abstract

This work aims to improves the chaotic behavior of classical logistic chaotic system for voice encryption. In this study, the classical chaotic system was enhanced. This enhanced map has many advantages like a wider chaotic range, more unpredictable, and better ergodicity than many existing chaotic maps (i.e. including 1D and 2D maps). The effectiveness of the improved chaotic system was verified by the bifurcation diagram, performing NIST SP 800-22 and Lyapunov exponent. On this basis, an efficient tweakable voice encryption algorithm was proposed to protect the security of digital voice transmission. The proposed scheme is based on the speech signal being pre-processed to automatically remove silent or voiceless segments, resulting in the extraction of relevant parts of speech for encryption. This leads to a significant reduction in both computing time and resources requirements, as well as the confusion-diffusion architecture. With the aid of the tweak, where each original voice has multiple different encrypted voices using the same secret key which saves time and makes the cost lower compared to changing the key to the proposed scheme. These features make the proposed speech encryption algorithm suitable for real-time communication. In this manner, it is demonstrated that our encryption system effectively withstands known/chosen plaintext attacks. The experimental results demonstrate that the proposed algorithm can withstand several types of attacks through voice encryption. The research results shed new light on the data security in the transmission of voices.