George Theodorakopoulos
Expected Graduation: Spring 2007
Resume
Research Interests
Trust and Reputation in Ad-Hoc/Peer-to-Peer Networks, Network Security My Master's thesis was on evaluating trust evidence in ad-hoc networks. The question answered is how much user A can trust user B if they have had no previous interaction. Since the network is ad-hoc, there is no centralized authority that A can consult; he can only count on evidence that other users provide about B. But these users' trustworthiness has to be taken into account, too, and aggregated into the computation. I used an algebraic framework (semiring) to model the properties that evidence aggregation should have in order to be as accurate as possible, and yet robust in the presence of adversaries. This framework extends PGP's Web of Trust concept, but also applies to e-commerce (finding a trusted online merchant). I am currently extending this approach by actually modeling the interactions between the network users. Game theory is used to model the users as strategic players trying to maximize a utility function. Elements from linear system theory are used to link the computation of trust to the topology of the network. The computation is viewed as a linear system, the steady state of which is the result of the computation.
Publications
George Theodorakopoulos and John S. Baras, IEEE Journal on Selected areas in Communications, Special Issue on Security in Wireless Ad-Hoc Networks, February 2006.
George Theodorakopoulos and John S. Baras, Best Paper Award in the ACM Workshop on Wireless Security (WiSe'04) (in conjunction with ACM Mobicom 2004), Oct. 2004
George Theodorakopoulos, ISR Technical Report MS 2004-2, MSc Thesis, May 2004
Internships
Contact Information
Adress: Institute for Systems ResearchElectrical and Computer Engineering Department
3182 AV Williams Bldg.
University of Maryland
College Park, MD 20742
Tel No.: 301-405-6561
email: gtheodor@umd.edu
Link: http://www.isr.umd.edu/~gtheodor
