Research Statement Theme 1: Secure Extensible Distributed Systems the First Research Project Explores a Unified Declarative Platform for Specifying, Implementing, and Analyzing

My research focuses on the development of novel software methodologies and platforms to aid in the development of secure and formally verifiable distributed systems that can be easily composed and adapted in the face of changing network conditions and application requirements. My work is motivated by the observation that as sophisticated, bandwidth-intensive, and even mission-critical services are being deployed over heterogeneous network infrastructure, there is increased demand for new network protocols that can flexibly adapt to a wide range of variability in network connectivity and data traffic patterns. This has resulting into the proliferation of new overlay networks that use the existing Internet to enable deployable network evolution and introduce new services, and cummulated into recent efforts at clean-slate efforts aimed at redesigning the Internet. Given the proliferation of new architectures and protocols, there is a growing consensus on the need for formal software tools and programming frameworks that can facilitate the design, implementation, and verification of new protocols. To address the above challenges, I have centered around three main projects: (1) secure extensible distributed systems, (2) adaptive composable networks, and (3) formal network verification. At the core of these three research projects is my use of declarative networking [10, 9, 7, 8], a framework that supports extensible specifications of networks. A declarative approach enables modular reuse of resources and functions by allowing network programmers to say what they want, without worrying about the details of how to achieve it. The declarative approach provides not only compactness of specification, but also the flexibility to support a wide range of routing protocols and overlay networks. In addition, the technique offers benefits such as formally defined semantics, optimizability and the potential for safety checks. I build upon the declarative networking foundation with a combination of formal analysis, language design, implementation and empirical measurements. I aim to design distributed systems with strong theoretical foundations achieved with the aid of formal tools such as automated theorem provers and model checkers. I further validate these designs by developing system prototypes that are experimentally evaluated on real testbeds such as PlanetLab, and the ORBIT wireless testbed. I actively collaborate with industry partners, most recently with AT&T Research, BBN Technologies, LogicBlox Inc., and Microsoft Research to discover challenging practical problems and realize research ideas in prototypes developed for real-world settings. My research brings together key ideas from the networking, database, programming languages, and formal methods communities. The National Science Foundation (NSF) and DARPA has recognized the inter-disciplinary flavor of the overall research by funding my various projects across core NSF computer science programs in Computing and Communication Foundations (CCF), Computer and Networked Systems (CNS), and Information and Intelligent Systems (IIS), and DARPA networking programs. See [2] for the list of the NSF and DARPA grants. Reflecting the inter-disciplinary nature of my research, my research findings have been published in selective venues in the areas of databases [13, 25, 6, 5, 7], networking [12, 3, 15, 21, 11, 10], distributed systems [18, 9], security [17, 19], and formal methods [20, 22, 23]. I have co-chaired workshops that span multiple communities: the CoNEXT 2008 Student Workshop and the NetDB 2009 workshop co-located with SOSP. Since joining Penn in 2007, I have graduated two doctoral students co-advised with faculty members in the areas of networking (Jonathan M. Smith) and security (Matt Blaze). I currently co-advise doctoral students (including two female students) with faculty members in the areas of databases (Zachary Ives), and formal methods (Andre Scedrov and Oleg Sokolsky). Two Penn undergraduates recently involved in my research projects are now pursuing their doctoral degrees at UC Berkeley and Harvard University. One of them received honorable mention for the Computing Research Association (CRA) outstanding undergraduate award.