Date:
Monday, April 18, 2016, 11:30am to 1:00pm
Location:
Maxwell Dworkin 119, 33 Oxford Street, Cambridge
Speaker: Goergios Kellaris (CRCS Postdoctoral Fellow)
Title: Accessing Data while Preserving Privacy
Abstract:
We initiate a formal research of the privacy-efficiency tradeoff of secure database systems. Such systems, such as CryptDB and Cipher-base, try to mitigate the high costs of full-fledged cryptographic solutions by relaxing the security guarantees they provide. We provide abstract models that capture the basic properties of these systems and identify their fundamental leakage channels. These models allow performing a generic and implementation independent investigation of the inherent tradeoffs between security and efficiency. In particular, this modeling allows us in some cases to devise generic reconstruction attacks where the server learns the secret attributes of every record stored in the database, pointing to inherent limitations of these models.
We present a new model of differentially private storage where differential privacy is preserved even against an attacker that controls the data and the queries made to it. We give a generic construction of differentially private storage that combines ORAM and differentially private sanitizers. We also provide efficient constructions and lower bounds for some specific query sets. We have implemented some of our algorithms, and report on their efficiency.
Authors: Georgios Kellaris with George Kollios, Kobbi Nissim, and Adam O’Neill
Bio:
Since September '15, I work as a Post-Doctoral Fellow at CRCS, Harvard University, and at Boston University. I received my Ph.D. degree in Computer Science and Engineering from the Hong Kong University of Science and Technology (2015), under the supervision of prof. Dimitris Papadias. My studies were supported by the Hong Kong Ph.D. Fellowship Scheme. I hold a 4-year B.Sc. in Informatics and Telecommunications from the University of Athens (2006) and a 2-year M.Sc. degree in Digital Systems from the University of Piraeus (2008). From September '08 until November '09, I was a Research Associate at the Information Systems Laboratory, University of Piraeus under the supervision of Prof. Yannis Theodoridis. On November '09 until July '10, I worked as a Research Fellow at the School of Information Systems, Singapore Management University (SMU) under the guidance of prof. Kyriakos Mouratidis. From July '12 to September '12, I worked as a Project Officer at the School of Computer Engineering, Nanyang Technological University in Singapore, under the supervision of prof. Xiaokui Xiao. From June '14 until August '14 I was a Visiting Researcher at Boston University under the supervision of prof. George Kollios. My research interests include databases and differential privacy.
See also: CRCS Lunch Seminar