Abstract: In the age of cloud computing and distributed blockchains outsourcing of storage and computation has become quite prevalent: Databases and email are now mostly hosted by large providers like Amazon or Google driving down the costs of on-premises infrastructure and allowing anyone to run SQL queries fast or read email 24/7; Cryptocurrency blockchains (e.g., Bitcoin) are maintained by powerful miners enabling even lightweight nodes running on smartphones to access, for example, information about previous transactions and blocks. While this new outsourcing paradigm has undoubtedly created economies of scale it is clear that most of the computation and storage is now taking place in adversarial environments, raising concerns about the trustworthiness and privacy of our online activities.
In this talk I will present research that we have been doing over the last few years to address the aforementioned problems. First, I will describe protocols for verifiable computation which enable a lightweight node to outsource his storage to an untrusted powerful server so that the correctness of subsequent queries, ranging from simple database queries to general-purpose SQL, can be efficiently verified. Second, I will present some of our work on privacy of data and computations, and in particular on searchable encryption, where a lightweight node stores his encrypted files with a server in a way that various queries (e.g., keyword search) can still be supported efficiently. I will continue with some applications on stateless blockchains, privacy-preserving cryptocurrencies and end-to-end encrypted email and will conclude with several future directions I am planning to pursue.
Bio: Charalampos (Babis) Papamanthou is an Assistant Professor of Electrical and Computer Engineering at the University of Maryland, College Park, where he joined in 2013 after a postdoc at UC Berkeley. At Maryland, he is also affiliated with the Institute for Advanced Computer Studies (UMIACS), where he is a member of the Maryland Cybersecurity Center (MC2). He works on applied cryptography and computer security---and especially on technologies, systems and theory for secure and private cloud computing. While at College Park, he received the NSF CAREER award, the Google Faculty Research Award, the Yahoo! Faculty Research Engagement Award, the NetApp Faculty Fellowship, the UMD Invention of the Year Award, the Jimmy Lin Award for Invention and the George Corcoran Award for Excellence in Teaching. His research has been funded by federal agencies (NSF, NIST and NSA) and by the industry (Google, Yahoo!, NetApp, Amazon and Blockchain Institute). His PhD is in Computer Science from Brown University (2011) and he also holds an MSc in Computer Science from the University of Crete (2005), where he was a member of ICS-FORTH. His work has received over 4,500 citations and he has published in venues and journals spanning theoretical and applied cryptography, systems and database security, graph algorithms and visualization and operations research.