SPEECH ENCRYPTION METHOD AND DEVICE, SPEECH DECRYPTION METHOD AND DEVICE

摘要

A speech encryption method for encrypting a digital speech signal includes the steps of generating an encryption key, deriving a plurality of voice feature data from the digital speech signal, determining a corresponding shift parameter according to the encryption key and converting the voice feature data derived therefrom into converted speech data based on the shift parameter, and determining corresponding dual-tone multi-frequency (DTMF) data according to the encryption key and interleaving the DTMF data with the converted speech data so as to obtain a scrambled speech signal.