Series ended Lecture
Degradation of Anonymous Protocols

About the series

Brian Levine, Assistant Professor at University of Massachusetts Amherst
Clay Shields, Assistant Professor Georgetown University

With widespread acceptance of the Internet as a public medium for communication and information retrieval, there has been rising concern that the personal privacy of users can be eroded by cooperating network entities. A technical solution to maintaining privacy is to provide anonymity.

There have been a number of protocols proposed for anonymous network communication. We show there exist attacks that degrade the anonymity of all existing protocols. We use this result to place an upper bound on how long existing protocols, including Crowds, Onion Routing, Hordes, and DC-Net, can maintain anonymity in the face of the attacks described. This provides a analytical measure by which the protocols can be compared. Additionally, we show how violating an assumption of the attack allows malicious users to setup other participants to falsely appear to be the initiator of a connection. Finally, we briefly discuss our work on responder anonymity and mutual anonymity. We present Anonymous Peer-to-peer File Sharing (APFS) protocols, which provide mutual anonymity for peer-to-peer file sharing. APFS addresses the problem of long-lived Internet services that may outlive the degradation present in current anonymous protocols.

About the Lecturers:
Brian Neil Levine is an assistant professor in the Department of Computer Science at UMass Amherst. His research interests are in the areas of computer networks, network security, and group communication. His most recent interests are in IP anonymity, peer-to-peer networking, and wireless networking. He is the recipient of an NSF Career grant and is the co-chair of the 2002 International Workshop on Networked Group Communication. He received a PhD in Computer Engineering from the University of California Santa Cruz in 1999.

Clay Shields is an assistant professor of Computer Science at Georgetown University. After an undergraduate career at the University of Virginia, he served as an infantry officer in the 101st Airborne Division, and went on to receive his PhD in Computer Engineering from the University of California Santa Cruz in 1999. Clay studies issues in network security, particularly methods of locating the source of network attacks, and means of providing individual privacy.

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Past events in this series

August 7, 2002, 4:00 p.m. – 5:00 p.m.