End-to-end speech encryption algorithm based on speech scrambling in frequency domain

The security situation of mobile communication becomes even more grim, at present, the complete bug-free secure communications system solutions has not been found. For the realization of the end to end secure encrypted communication of speech, this paper proposes a speech encryption algorithm, which can penetrate compression encoder. The algorithm scrambles the speech signal in frequency domain based on FFT transformation domain in the sender, and it decrypts and reconstructs the signal in the receiving end. The encrypted speech signal still has the characteristics of speech, The residual intelligibility of the speech is low enough and the speech bandwidth does not be widen. Scramble matrix can meet the needs of speech transmission security and achieve one key for one secret communication flexibly. End-to-end communication can avoid the common eavesdropping and theft, and has a relatively broad prospects for development.