[PAST EVENT] Colloquium: Systems without Cooperation

April 19, 2013
3pm - 4pm
McGlothlin-Street Hall, Room 20
251 Jamestown Rd
Williamsburg, VA 23185Map this location
The Internet is no longer the cooperative, technological playground it once was. Successful networked systems must now account for potentially competing interests. The protocols are the rules relegating the venue for this competition, but those rules often lack enforcement. I will present the application of economics and trusted hardware to keep participants in a networked system from deviating from the letter and spirit of a protocol.

First, I will apply economic mechanism design to keep selfish users from gaining at the expense of others. I will show that the popular BitTorrent system uses, not tit-for-tat as widely believed, but an auction to decide which peers to serve. This model captures known, performance-improving strategies, and shapes or thinking toward new, effective incentive mechanisms.

Second, I will apply trusted hardware to keep both selfish and malicious users from "equivocating," or sending semantically conflicting messages. I will present TrInc (Trusted Incrementer), a small piece of trusted hardware intended for use in large-scale distributed systems. With case studies and an implementation, I will demonstrate that TrInc is a practical primitive for protecting a wide range of systems.

These two examples together demonstrate the importance of aligning the assumptions of economics and large-scale systems. Doing so allows us to develop new mechanisms that foster cooperation among the otherwise self-interested.

Bio: Dave Levin is a research scientist at the University of Maryland. His research interests span many areas of systems and networking, and include achieving cooperation among self-interested parties, protecting user privacy, resisting censorship, and building new systems for which security and incentives as first-order goals.

Department of Computer Science