UVP: Uncovering WeChat VoIP Peers over Time Jiazheng Wang Zhenlong Yuan Department of Automation, Tsinghua University Research Institute of Information Technology Beijing, China Tsinghua University e-mail:
[email protected] Beijing, China e-mail:
[email protected] Jun Li Research Institute of Information Technology, Tsinghua Tsinghua National Lab for Information Science and Technology Beijing, China e-mail:
[email protected] Abstract—VoIP is pervasively used in online voice Control channel protocols, Session Initiation Protocol (SIP) conversations through internet, and WeChat has become one [2] for example, are designed to know where the caller and of the most successful VoIP applications. Any leakage of VoIP callee are, understand the network status of them before the call information will threat user confidentiality and privacy, conversation actually starts. During the conversation, control and thus may lead to a catastrophic consequence to VoIP channel protocols also monitor and adapt to network service providers. In this paper, a thorough behavior analysis changes. Based on the information acquired by the control of WeChat proprietary VoIP protocols is performed and we channel, data channel can be set up to deliver audio chucks, find the anonymity of users can be compromised by flow whether relayed by a third party server, in a so called relay correlation attacks. Hereby a new framework UVP is based model, or directly between the VoIP peers, in the so proposed. UVP works in a global monitoring manner and called peer to peer model. leverages a new, efficient flow distance metric, evolved from Dynamic Time Wrapping, to correlate traffics from caller and VoIP services are responsible to protect the anonymity of callee.