Building reputation-based trust in online systems

Thursday, 16th September 2010, 10:30 am (PDCC Meeting Room)
Speaker: Professor Karl Aberer (EPFL)
Title: Building reputation-based trust in online systems

Trust has become a central issue in today’s online world, where interactions are performed frequently with complete strangers. Reputation-based trust has been proposed and is being used as a solution to deal with this problem. However these systems suffer from different vulnerabilities, such as ballot stuffing, strategic behaviors or whitewashing and at the same time have to exhibit efficient performance at a Web scale. In this talk we give an overview of the development of reputation-based trust management systems, from the early days with often somewhat naïve assumptions to more sophisticated approaches designed to counter many possible attacks with limited resources. We will identify whitewashing as a particular critical problem and give an outlook of how this problem might be addressed in the context of the social and semantic Web.


Karl Aberer is a Professor for Distributed Information Systems at EPFL Lausanne, Switzerland, and director of the Swiss National Centre for Mobile Information and Communication Systems (NCCR-MICS). His research interests are on decentralization and self-organization in information systems with applications in peer-to-peer search, overlay networks, trust management and mobile and sensor networks. Before joining EPFL in 2000 he was leading the research division of open adaptive information systems at the Integrated Publication and Information Systems Institute (IPSI) of GMD in Germany, which he joined in 1992. There his work concentrated on XML data management and cross-organizational workflows. He studied mathematics at ETH Zürich where he also completed his Ph.D. in theoretical computer science in 1991. From 1991 to 1992 he was postdoctoral fellow at the International Computer Science Institute (ICSI) at the University of California, Berkeley. He is member of the editorial boards of several journals, including ACM Transaction on Autonomous and Adaptive Systems and World Wide Web Journal and member of ICDE steering committee. Recently he served as PC co-chair of ICDE 2005, MDM 2006, ISWC 2007 and P2P 2009. He is also consulting for the Swiss government in research and science policy as a member of the Swiss Research and Technology Council (SWTR).