EURASIP Journal on Applied Signal Processing 
Volume 2003 (2003), Issue 10, Pages 1027-1042
doi:10.1155/S1110865703304019

On Securing Real-Time Speech Transmission over the Internet: An Experimental Study

Alessandro Aldini,1 Marco Roccetti,2 and Roberto Gorrieri2

1Instituto di Scienze e Tecnologie dell'Informazione (STI), Università degli Studi di Urbino, Urbino 61029, Italy
2Dipartimento di Scienze dell'Informazione, Università di Bologna, Bologna 40127, Italy

Received 27 May 2002; Revised 3 January 2003

Abstract

We analyze and compare several soft real-time applications designed for the secure transmission of packetized audio over the Internet. The main metrics we consider for the purposes of our analysis are (i) the computational load due to the coding/decoding phases, and (ii) the computational overhead of the encryption/decryption activities, carried out by the audio tools of interest. The main result we present is that an appropriate degree of security may be guaranteed to real-time audio communications at a negligible computational cost if the adopted security strategies are integrated together with the playout control mechanism incorporated in the audio tools.