Title: Securing DHT-based P2P SystemsSpeaker: Yongdae Kim, Assistant Professor, University of MinnesotaDate: Thursday June 29, 4:00pm~5:30pm 2006Place: ICP Lecture RoomAbstract: Since 2001, DHT (Distributed Hash Table) has been major toolto build distributed applications and systems on the Internet. (e.g.Chord has already 3,000 citations in 4 years) Examples include 1) webfarms that prevents fresh crowd effect, 2) storage systems such asOceanStore, CFS, 3) P2P DNS such as CoDNS and CoDoNS, 4) P2P webcaching services such as Coral, 5) more generic binding services suchas OpenDHT and SFR, and 6) new Internet design proposals such as I3.However, we argue that most of these systems are vulnerable to alot of service disruption and misuse attacks even with small number ofcollaborative attackers.In this talk, I will introduce two different mechanisms that cansecure systems built on top of DHT. In the first part of the talk, weintroduce how to \\"emulate\\" a central entity on DHT, which is robustagainst collaborative attackers. Such central entity be used forenforcing security policy as TTP in centralized systems. We show thatusing this mechanism we can build robust accounting mechanism on P2Pfile archiving systems.In the second part of the talk, we introduce the first secure DHTrouting protocol robust against collaborative attackers. In DHTrouting, a node sends message to a key k, and a node resposible forthe key (called root (k)) should be the destination of the message.Unfortunately, none of the existing DHT routing mechanisms does notallow the sender verifies the root (k). The proposed SDHT protocolprotocol provides internal as well as external verifiability of theroot.Finally, if time permits, I will introduce FIND (Future InterNetDesign) and GENI (Global Environment for Network Innovations), effortto build future Internet supported by NSF (National ScienceFoundation) and other US government oganization. Researchers and USGovernment are currently preparing to design a new Internet with 10year plan, which includes security as one of main design criteria.Bio:Yongdae Kim is an Assistant Professor in the Department of ComputerScience at the University of Minnesota, Twin Cities. He received Ph.D. degree from USC in May 2002 under the guidance of Dr. Gene Tsudik.Before joining to Univ. of Minnesota, he was a research staff at UCIrvine (2001-2002) and ETRI, Korea (1993-1998). His current researchinterests are security issues for networks and distributed systemssuch as storage systems, P2P systems, sensor networks. Dr. Kimreceived the National Science Foundation CAREER Award in 2005, and U.of Minnesota McKnight Land-grant Professorship in 2006.--++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++Yongdae Kim (office phone) 1-612-626-7526+Assistant Professor, University of Minnesota - Twin Cities+kyd (at mark) cs.umn.edu, http://www.cs.umn.edu/~kyd+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++