Physical Layer Security

Tactical communications among coalitions of mobile units and within on-demand deployments of military installations heavily rely on the establishment of wireless networks. However, the open nature of the wireless medium leaves it exposed to adversarial eavesdroppers. Using commodity radio hardware, unauthorized adversaries can easily intercept packet transmissions. Although encryption can be applied to ensure information secrecy, eavesdroppers can still perform low-level RF and traffic analysis, and capture with different degrees of certainty several communication attributes, such as the packet size, packet durations duration, inter-packet times, traffic directionality, channel state information, etc. Contextual information can subsequently be used to launch sophisticated attacks (e.g., selective jamming/dropping, targeted node compromise, intelligent DoS attacks, etc.).
We develop physical-layer security methods which prevent sophisticating adversaries from using easy-to-capture communication attributes for launching selective attacks on coalition networks. These methods exploit advances in MIMO and self-interference suppression to provide integrated transmitter/receiver friendly jamming, with the goal of hiding the communication patterns of the coalition. We further employ graph-theoretic methods for constructing robust broadcast communication modes that can withstand attacks from insiders, with knowledge of globally shared secrets.
Related Projects

ARO: Blinding Eve: Methods for Concealing Wireless
Communications in Mobile Coalitions - with Marwan Krunz (PI).
NSF CNS-1016943: Enemies from Within: Thwarting Sophisticated Insider Attacks in Wireless Networks - with Marwan Krunz (co-PI).