Active Timing Based Approach for Tracking Anonymous Peer-to-peer Network in VoIP

Peer-to-peer VoIP calls are popular due to theirlow cost and convenience. When these calls are encrypted andanonymized the network becomes a secured one. Tracing of theanonymous VoIP call users are important and the tracedinformation about them should be sent to the server to knowhow long the users are in communication.The key challenge in tracking encrypted VoIP calls acrossanonymous communication system is to identify the correlationbetween the VoIP flows of the caller and the callee. Since all thetraffic of the peer-to-peer VoIP calls are encrypted, the best wayto track anonymous VoIP calls across the internet is using theActive timing based correlation. It is done by embedding aunique watermark into the inter-packet timing domain. Theanalysis shows that it only takes several milliseconds timeadjustment to make normal VoIP flows highly unique and theembedded delay value could be preserved across the low latencyanonymizing network. In this proposal, tracking of anonymousVoIP calls across internet was successfully achieved by usingactive time based correlation method and the resultsdemonstrate that tracing of anonymous peer-to-peer VoIP callson the internet is feasible and low latency anonymizing networksare susceptible to timing attacks.