A Comprehensive Solution Based on Watermarking and Encryption for Securing a Voice Over Internet Protocol System

Abstract

Voice over Internet Protocol is an interactive service that requires less than 150 ms of delay from end-to-end to emulate what today phones perform. Implementing a security mechanism introduces further delay, and optimization has to be done to meet the Quality of service requirements. In this paper, we propose a new solution to secure Voice over Internet Protocol communication using a high capacity blind watermark based on classification and Discrete Wavelet Transform for data source authentication and tampering localization. The used algorithm can embed the mark, with up to one kilobit per second with a Signal to Noise Ratio up to 21dB. It is able to detect tampering in real time and it can resist to packet loss. Moreover, to maintain the conversation privacy, we used the encryption. Several tests were conducted to help us choose the appropriate encryption algorithm that provides the best performance and without degrading the voice quality. These tests were performed on devices with different types of hardware and software, including some devices with lower processing power. The obtained results are very satisfactory since the tradeoff between providing the Voice over Internet Protocol security and maintaining a good Quality of Service has been successfully fulfilled.