Correlation-Based Traffic Analysis on Encrypted VoIP Traffic

In this paper, we focus on traffic analysis on encrypted Voice over IP (VoIP) calls at the network level and the application level. The network-level traffic analysis aims to correlate VoIP traffic flows with features in time domain and frequency domain. The application-level traffic analysis at identify speeches in encrypt VoIP calls. We verified our analysis approaches with experiments over existing anonymity networks and experiments results show that the successful rate for flow correlation and speech identification can approach 0.9 and 0.98 respectively.