CryptDB: Protecting Confidentiality with Encrypted Query Processing

Online applications are vulnerable to theft of sensitive information because adversaries can exploit software bugs to gain access to private data, and because curious or malicious administrators may capture and leak data. In this talk, I will describe CryptDB, a system that provides practical and provable confidentiality in the face of these attacks for applications backed by SQL databases. It works by executing SQL queries over encrypted data using a collection of efficient SQL-aware encryption schemes. CryptDB can also chain encryption keys to user passwords, so that a data item can be decrypted only by using the password of one of the users with access to that data. As a result, a database administrator never gets access to decrypted data, and even if all servers are compromised, an adversary cannot decrypt the data of any user who is not logged in. An analysis of a trace of 126 million SQL queries from a production MySQL server shows that CryptDB can support operations over encrypted data for 99.5% of the 128,840 columns seen in the trace. Our evaluation shows that CryptDB has low overhead, reducing throughput by 14.5% for phpBB, a web forum application, and by 26% for queries from TPC-C, compared to unmodified MySQL.

Nickolai Zeldovich is Douglas T. Ross Career Development Assistant Professor at MIT's EECS department and a member of the Computer Science and Artificial Intelligence Laboratory. His research interests are in building practical secure systems, from operating systems and hardware to programming languages and security analysis tools. He received his PhD from Stanford University in 2008, where he developed HiStar, an operating system designed to minimize the amount of trusted code by controlling information flow. In 2005, he co-founded MokaFive, a company focused on improving desktop management and mobility using x86 virtualization. Prof. Zeldovich received a Sloan fellowship in 2010, and an NSF CAREER award in 2011.