Root ORAM: A Tunable Differentially Private Oblivious RAM

Web Published:

Princeton Docket # 16-3221-1

Researchers at Princeton in the Department of Electrical Engineering have designed a unique Oblivious RAM (Root ORAM) that provides an application- specific low bandwidth with rigorous privacy guarantees of a differentially private ORAMs with tunable privacy-utility trade-off to achieve private access of data.


Use of current oblivious RAM (ORAM) in high-performance and bandwidth-constrained applications is challenging due to significant bandwidth overheads. This invention provides low overhead schemes to perform oblivious access. It takes into account the design space and provides a highly tunable scheme for oblivious access while giving concrete privacy guarantees. This invention formalized the notion of a differentially private ORAM which can be used to rigorously quantify ORAM security. Root ORAM, a family of practical ORAMs, offers a tunable trade-off between the desired bandwidth overhead and system security, including a design point that supports constant bandwidth construction and thereby provides the rigorous privacy guarantees of differentially private ORAMs.


This Invention can be tuned to achieve application-specific bandwidth constraints at the cost of statistical privacy guarantees which are quantified under the differential privacy framework.



Sameer Wagh, Paul Cuff, Prateek Mittal. Root ORAM: A Tunable Differentially Private Oblivious RAM. Arxiv:1601.03378v1, 13 Jan 2016



Prateek Mittal is an assistant professor in the Electrical Engineering Department at Princeton University, affiliated with the Department of Computer Science and Center for Information Technology Policy. He received his Ph.D. from University of Illinois, Urbana Champaign. His interests include the domains of privacy enhancing technologies, trustworthy social systems, and Internet/network security. He recently received the NSF Career Award and the Google Faculty Research Award among others.

Paul Cuff is an Assistant Professor in the Electrical Engineering Department.  He earned his Ph.D. at Stanford University.  His research speciality is information-theoretic security, through which he investigates the fundamental limits of secure communication and data encoding.  Prof. Cuff received the NSF Career Award in 2014 and the AFOSR Young Investigator Program Award in 2015.

Sameer Wagh is a third year graduate student in the Electrical Engineering Department at Princeton University completing his Ph.D. under the supervision of Prof. Prateek Mittal. He completed his Bachelors in Engineering Physics from Indian Institute of Technology, Madras. As a part of his PhD, Sameer works on developing practical, efficient solutions to problems in applied cryptography thereby building systems with security at their core.


Intellectual Property & Development status

Patent protection is pending.

Princeton is currently seeking commercial partners for the further development and commercialization of this opportunity.



Chris Wright

Princeton University Office of Technology Licensing • (609) 258-6762•


Patent Information:
For Information, Contact:
Chris Wright
Licensing Associate
Princeton University
Sameer Wagh
Paul Cuff
Prateek Mittal