SEMINAR ANNOUNCEMENT
              CENTER FOR SECURE INFORMATION SYSTEMS
                     GEORGE MASON UNIVERSITY 
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              Date :  Wednesday, June 19,2013
              Time :  10:00 - 11:00
          Location :  Research Hall, Room 401 
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On the Effectiveness of Sybil Defenses via Online Social Networks 
Prof. Jun Li 
Department of Computer and Information Science 
University of Oregon

Abstract
Through forging a large number of fake identities called Sybils, Sybil attacks can tremendously damage many normal operations in cyber space.
They can manipulate voting results, send spam, or influence ratings of a product, just to name a few.  A recent trend of Sybil defense is to utilize the online social networks (OSNs) of users in a target system, and exploit OSN graphs to either detect Sybil nodes (Sybil detection) or limit the negative influence from Sybils (Sybil tolerance).  Albeit different in their working principle, all these OSN-based approaches rely on a central assumption: It  is difficult for an attacker to create attack edges to connect Sybils with benign users.  In this talk, we revisit this assumption, and identify, analyze, and evaluate state-of-the-art, OSN-based Sybil defense approaches, with a particular focus on their effectiveness-or lack thereof-under the new conditions when Sybils may connect to benign nodes with a dramatically increased number of attack edges.  We then discuss how this research may help point to new, more effective Sybil defense principles and designs. 

**Point of contact:  Prof Sushil Jajodia [log in to unmask] =================================================================