Thwarting WiFi SideChannel Analysis through Traffic Demultiplexing Yangyi

Thwarting Wi-Fi Side-Channel Analysis through Traffic Demultiplexing Yangyi Chen Supervisor: Prof. Xiao. Feng Wang On-going research project in collaboration with UNL, Microsoft Research and Mc. Gill University

Side-channel information leaks Threats in different communication scenarios Web browsing • http: //www. youtube. com/user/mountmic#p/u/3/3 s. GH 9 Kp. YOJk Video-streaming Voice over-IP Particularly serious in wireless networks (shared-medium nature) Mostly caused by analyzing statistical characteristics of encrypted traffic Distributions of packet sizes Inter-packet timings

Current defense techniques Change the distribution of packet sizes Padding packets Faking superfluous packets Chopping packets into fixed size segments Traffic morphing Limitations of those techniques Significant communication overheads Hard to deploy

Our solution: Traffic Demultiplexing Data transmission

Our solution: Traffic Demultiplexing A simple example Traffic on each interface PDF on each interface

Design and implementation Network stack with three virtual interfaces

Packets flow on receiver and sender sides

Demultiplexing Scheduler: Masquerading Demultiplexing

Real-world Deployment and Demo setup Three laptops First with our AP-side prototype driver installed, equipped with a Proxim AP-2000 11 b/g Cardbus series. Second with our Client-side prototype driver installed, equipped with D-link WNA-2330. Third with wireless card set to monitor mode and use Wireshark to collect traffic. • http: //www. youtube. com/user/fccherry 091? feature=mhum

Thanks!