Frequency-domain speech scrambling/descrambling techniques implementation and evaluation on DSP

Abstract

Speech scrambling/descrambling has always been a key component in secure communication systems. The paper describes the real-time implementation of frequency-domain speech scrambling/descrambling techniques on Texas Instruments' TMS320C6711 DSP. Three techniques, frequency-inversion, frequency hopping inversion and rolling code inversion, have been successfully implemented. Subsequently, the results of these techniques are evaluated and compared on the basis of their level of security