[Theory Seminar] Adam Smith

October 26, 2016 @ 12:00 pm – 1:00 pm

Speaker: Adam Smith

Affiliation: Penn State University.

Title: Privacy, Information and Generalization


Consider an agency holding a large database of sensitive personal
information — medical records, census survey answers, web search
records, or genetic data, for example. The agency would like to
discover and publicly release global characteristics of the data (say,
to inform policy or business decisions) while protecting the privacy
of individuals’ records. I will begin by discussing what makes this
problem difficult, and exhibit some of the nontrivial issues that
plague simple attempts at anonymization and aggregation. Motivated by
this, I will present differential privacy, a rigorous definition of
privacy in statistical databases that has received significant

In the second part of the talk, I will explain how differential
privacy is connected to a seemingly different problem: “adaptive data
analysis”, the practice by which insights gathered from data are used
to inform further analysis of the same data sets. This is increasingly
common both in scientific research, in which data sets are shared and
re-used across multiple studies. Classical statistical theory assumes
that the analysis to be run is selected independently of the data.
This assumption breaks down when data re re-used; the resulting
dependencies can significantly bias the analyses’ outcome. I’ll show
how the limiting the information revealed about a data set during
analysis allows one to control such bias, and why differentially
private analyses provide a particularly attractive tool for limiting

Based on several papers, including recent joint works with R. Bassily,
K. Nissim, U. Stemmer, T. Steinke and J. Ullman (STOC 2016) and R.
Rogers, A. Roth and O. Thakkar (FOCS 2016).


Adam Smith is a professor of Computer Science and Engineering at Penn
State. His research interests lie in data privacy and cryptography,
and their connections to machine learning, statistics, information
theory, and quantum computing. He received his Ph.D. from MIT in 2004
and has held visiting positions at the Weizmann Institute of Science,
UCLA, Boston University and Harvard. In 2009, he received a
Presidential Early Career Award for Scientists and Engineers (PECASE).
In 2016, he received the Theory of Cryptography Test of Time award,
jointly with C. Dwork, F. McSherry and K. Nissim.