M.S. in Telecommunications at George Mason University

Title: Improving and Securing Mobile Internet Accesses

Abstract: With the rapid advancement of mobile communication technology, increasingly more users rely on mobile devices, such as smart phones and PDAs, to connect to the Internet, However, this technology trend and wide user accessibility have presented new challeng...es to the current practice from various aspects, ranging from improved Quality of Service to better security and privacy demanded by mobile users.

In this talk, I will discuss some of these challenges and my research solutions to address them, in addition to an overview of my research. Specifically, I will discuss how to efficiently address the multiple dimensional heterogeneity problem in both on-demand and live streaming services. In order to solve increasingly serious problems of mobile malware on mobile devices, I will also present a novel technique to detect mobile malware in order to protect mobile users.


Bio:

Dr. Songqing Chen is an Assistant Professor of Computer Science in the Volgenau School of IT & Engineering. He received his Ph.D. from the College of William and Mary, 2004. His research interests mainly focus on design, analysis, and implementation of algorithms and experimental systems in distributed and networking environments, particularly, in the areas of Internet content delivery systems, Internet measurement and modeling, operating systems and system security, distributed systems, and high performance computing. Dr. Chen has served on various system and networking conference TPCs, including IEEE INFOCOM, ICDCS, ACM MM, and WWW. Currently, he is serving as the vice co-chair of ICDCS 2010 for the Internet/network protocol track. His research has been supported by NSF, HP Labs, and AFOSR. He is a recipient of the NSF CAREER Award and AFOSR YIP Award.Read More

Title: A Day in the Life of an Access Controller on the WWW

Abstract: We still wish to govern the accesses to resources residing on large, loosely coupled and mostly uncoordinated distributed systems such as the WWW. In order to do so, we wish to create access control frameworks that are sufficiently generic so that the...y can be used by multiple application domains. In order to do so, one needs to be able to define all relevant entities in a manner that is name-space independent, but yet customizable as needed. In addition, the framework needs to be able to interpret security policies and provide decisions that have to be computed amidst (distributed) divergences and failures. Additionally, enforcing some decisions made by such policy frameworks may change the policies themselves, thereby requiring the transactional and locking mechanisms in order enforce the rendered decisions. Yet, these policy frameworks, being constructed out of a collection of communicating processes, have to evolve from their birth to death in a manner that reflects their operational environment in a policy consistent manner. This talk describes some work that has been conducted in cooperation with a group of individuals on enhancing the eXtensibe Access Control Meta Language (XACML) and its enforcement framework.

Bio: Duminda Wijesekera is an associate professor in the Department of Computer Science at George Mason University, Fairfax, Virginia. During various times, his research interests have been in security, multimedia, networks, secure signaling (telecom, railway and SCADA), avionics, missile systems, web and theoretical computer science. He holds courtesy appointments at the Center for Secure Information Systems (CSIS) and the Center for Command, Control and Coordination (C4I) at George Mason University, and the Potomac Institute of Policy Studies in Arlington, VA. Prior to GMU he was at Honeywell Military Avionics, Army High Performance Research Center at the University of Minnesota, and the University of Wisconsin. His doctorates are in Computer Science and Logic from the University of Minnesota and Cornell University in 1997 and 1990, respectively.

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Exploring the Maze of MIX Networks and Malwares

Abstract: The concept of MIX is fundamental to all anonymous communication networks, and almost all existing anonymous networks used traffic mixing and transformation to achieve anonymity. It has long been believed that flow mixing and transformations would effectively dis...guise network flows, thus achieve good anonymity. In the first half of this talk, I will overview my work in investigating the fundamental limitations of flow mixing and transformation in achieving anonymity. I will describe how active flow watermarking in packet timing could transparently make a sufficiently long flow uniquely identifiable. I will also discuss how active flow watermarking can be applied to track anonymous, peer-to-peer VoIP calls on the Internet. In the second half of my talk, I will overview my work in malware analysis and defense.

Bio: Xinyuan Wang is currently an Assistant Professor in the Department of Computer Science at George Mason University. He received his BS and MS in Computer Science from Peking University and Chinese Academy of Space Technology respectively. He received his PhD in Computer Science from North Carolina State University in 2004 after years of professional experience in the networking industry. His main research interests are around computer network and system security – including malware analysis and defense, attack attribution, anonymity and privacy, VoIP security, digital forensics. He has developed the first inter-packet timing based packet flow watermarking scheme that is provably robust against timing perturbation. He has first demonstrated that it is feasible to track encrypted, anonymous peer-to-peer VoIP calls on the Internet. In his later work, he has demonstrated the fundamental limitations of existing low-latency anonymous communication systems in the presence of timing attack, and developed the first practical attack that has “penetrated” the Total Net Shield – the “ultimate solution in online identity protection” of www.anonymizer.com with less than 11 minutes worth of Internet traffic. Xinyuan Wang received the 2009 NSF Faculty Early Career Development (CAREER) Award, the 2009 GMU CS Outstanding Faculty Research award, and the 2004 ACM Graduate Student Research Competition Grand Finals Award (Third Place).Read More

Opportunistic Spectrum Access in Cognitive Radio Networks

Abstract: With the increasing ubiquity of wireless devices, radio spectrum has become a scarce resource. Moreover, recent measurement studies of the radio spectrum have shown that frequency bands allocated to licensed users are highly underutilized. I will give... an overview of my recent research on the design and analysis of wireless networks that exploit this underutilized spectrum opportunistically while avoiding harmful interference to the licensed users. The enabling technology for such opportunistic spectrum access is cognitive radio, which is a type of wireless device that can dynamically modify its transmission and reception parameters in response to its radio environment. My research results suggest that opportunistic spectrum access based on cognitive radio technology has the potential to dramatically increase the capacity of wireless networks. Real-world applications and future research directions will also be discussed.

Short Bio

Brian L. Mark is an Associate Professor of Electrical and Computer Engineering in the Volgenau School of Information Technology and Engineering. He received the B.A.Sc. (Bachelor of Applied Science) in Computer Engineering with an option in Mathematics in 1991 from the University of Waterloo and the Ph.D. in Electrical Engineering from Princeton University in 1995. He was a Research Staff Member at the NEC Computer and Communications Research Laboratory in Princeton, New Jersey from 1995-1999. In 1999 he was on part-time leave from NEC as a visiting researcher at Télécom ParisTech in France. He joined the Dept. of Electrical and Computer Engineering at George Mason University in 2000. He received an NSF CAREER Award in 2002. His main research interests lie in the design, modeling, and performance evaluation of communication networks. He is a Senior Member of IEEE and an Associate Editor of IEEE Transactions on Vehicular Technology.Read More