Sajal K. Das
Director, Center for Research in Wireless Mobility and Networking
(CReWMaN)
Department of Computer Science and Engineering
The University of Texas at Arlington
12:00 p.m., Wednesday, May 10, ITE 325B
Host: Prof. Dhananjay Phatak, phatak@cs.umbc.edu
In unattended and hostile environments, node compromise can become
a disastrous threat to wireless sensor networks and introduce
uncertainty in the aggregation results. A compromise node often
tends to comletely reveal its secrets to an adversary which in turn
renders purely cryptography-based approaches vulnerable. How to secure
the information aggregation process against node compromise attacks
and quantify the uncertainty in the aggregation results has become
an important research issue. In this talk, we will address this
problem by proposing a trust based framework, rooted in statistics
and other distinct yet closely coupled techniques. The trustworthiness
(reputation) of individual sensor nodes is evaluated with the help
of an information theoretic measure, Kullback-Leibler distance, that
identifies the compromised nodes through an unsupervised learning
algorithm. Upon aggregation, an opinion (metric defining the degree
of belief) is generated to represnt the uncertainty in the aggregation
result. As the result is disseimnated and assembled through the routes
to the sink, the opinion will be propagated and regulated by Josang's
belief model. Our trust based framework effectively quantifies the
uncertainty in the data as well as aggregation results. Experimental
results demonstrate that this framework provides a powerful mechanism
for detecting compromised nodes and reasoning about uncertainty
in the network. It can also purge false data to accomplish robust
aggregation in the presence of compromised nodes.
[This work is supported by an NSF grant.]
Dr. Sajal K. Das is a Professor of Computer Science and Engineering and the Founding Director of the Center for Research in Wireless Mobility and Networking (CReWMaN) at the University of Texas at Arlington (UTA). He is also a Honorary Professor of Fudan Univeristy, Shanghai, China and a Visiting Professor of IIT-Kanpur. His current research interests include sensor networks, security, resource and mobility management in wireless networks, pervasive computing, smart environments, and grid computing. He has published over 350 research papers, directed numerous funded projects, and holds 5 US patents in wireless mobile networks. He is a recipient of Best Paper Awards in IEEE PerCom'06, ACM MobiCom'99, ICOIN'01, ACM MSWIM'00, and ACM/IEEE PADS'97. Dr. Das is also a recipeint of UTA Academy of Distinguished Scholars Award (2006), University Award for Distinguished Record of Research (2005), College of Engineering's Research Excellence Award (2003) and Outstanding Faculty Research Award in Computer Science (2001, 2003). He coauthored the book "Smart Environments: Technology, Protocols and Applications" (John Wiley, 2005). He is the Editor-in-Chief of the Pervasive and Mobile Computing, and also an Associate Editor of IEEE Transactions on Mobile Computing, IEEE Transactions on Parallel and Distributed Systems, and ACM/Springer Wireless Networks. He served as the General Chair and TPC Chair of numerous IEEE and ACM Conferences.