A Lossless Audio Encryption Method based on Chebyshev Map

This paper presents a lossless and secure audio encryption method based on the chaotic Chebyshev map. Firstly, the input audio samples are preprocessed to obtain the integer and decimal parts. The integer parts are rescaled to the interval [0,255]. By iterating the Chebyshev map in the chaotic range using plaintext-dependent variables, the integer parts of the input audio sample are scrambled and then diffused. Finally, a post-processing operation is applied to the diffused audio samples. Keyspace and key sensitivity analysis, histogram analysis, the correlation between adjacent samples analysis, information entropy analysis, number of sample change rate analysis, and speed analysis results are presented. These security analysis results show that the proposed audio encryption method can be used in secure voice transmission applications.