Security and Efficiency of Feistel Networks Versus Discrete Chaos for Lightweight Speech Encryption

This paper compares examples of non-chaotic and chaotic ciphers from the viewpoint of their suitability for speech encryption, especially in real-time and lightweight cipher systems. The non-chaotic encryption scheme depends on a modified Generalized Feistel Network (GFN), Linear Feedback Shift Register (LFSR) and Substitution Boxes (S-Boxes). The chaotic encryption scheme utilizes a generalized modified tent map with multiple modes of operation. The security and efficiency of both schemes are analyzed using the perceptual tests: time waveform and spectrogram; the statistical tests: histogram, correlation coefficients, entropy and Mean Squared Error (MSE); and the computational complexity for two different test speech files. © 2018 IEEE.