Email:  
For Harvard (non DUS) related mails, please use For DUS related mails use csdus@seas.harvard.edu.  
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I am a professor of Computer Science at Harvard University, and a member of the Harvard SEAS Theory of Computing group. Previously, I was a principal researcher at Microsoft Research New England, and before that I was an associate professor (with tenure) at Princeton University’s Computer Science department. I hold a Ph.D from the Weizmann Institute of Science, and was a postdoctoral fellow at the Institute for Advanced Study in Princeton.
I am a theoretical computer scientist, interested in computational complexity, algorithms, cryptography, quantum computing and the theory of machine learning.
See also my curriculum vitae and brief bio. I also occasionally blog and tweet.
DUS: (On sabbatical Spring 2022.) I am co director of undergraduate studies (DUS) of Computer Science at Harvard together with Prof. Stephen Chong. Please email csdus@seas.harvard.edu for any DUS related matters. For information about the Computer Science concentration at Harvard see the page csadvising.seas.harvard.edu. See also my contact information and office hours.
Current activities: Member of the editorial board of the Theory of Computing Journal (ToC) and the Electronic Colloquium of Computational Complexity. Member of the Committee for the Advancement of Theoretical Computer Science (CATCS). I am a member of the scientific board of the Simons Institute for the Theory of Computing. I am a co organizer of the Harvard Machine Learning Theory seminar. Board member and co organizer of Addis Coder. I am also a member of the advisory board of the wonderful Quanta magazine. See my CV for past activities.
Current students: Yamini Bansal (coadvised with David Cox), Yueqi Sheng, ChiNing Chou, Prayaag Venkat, Beatrice Nash (coadvised with Misha Lukin), Yafah Edelman (coadvised with Cynthia Dwork).
Former students: Sharon Goldberg (co advised with Jennifer Rexford), David Xiao (co advised with Avi Wigderson), Mohammad Mahmoody, Moritz Hardt, Zhixian Lei, Preetum Nakkiran (coadvised with Madhu Sudan)
Former postdocs: Benny Applebaum, Thomas Holenstein, Guy Rothblum, Tselil Schramm.
Former interns: Moritz Hardt, Jonah Sherman, Yuan Zhou, LiYang Tan , Aaron Sidford, Aaron Potechin, Pravesh Kothari, Sam Hopkins.
Funding: I am currently supported by NSF grant CCF 1565264, a Simons Investigator Fellowship, DARPA grant W911NF2010021,and NSF grant DMS2134157. I am also grateful for support from Oracle Labs and past support by the NSF, as well as the Packard and Sloan foundations and the BSF.
Want to work with me? I am interested in both theoretical CS and the theory of machine learning. You can see this page for how to apply for graduate studies in computer science; we also have a new Quantum Science and Engineering program. Please do not email me with your resume  if you are interested in working with me, you can indicate this on your application and it will get to me. We also have some postdoc positions in both theoretical CS and theory of machine learning. I typically announce any such positions on my blog or Twitter, and also post these on the TCS jobs page. See this page for opportunities in the ML theory group.
Personal: I am married to Ravit Barak and father to Alma and Goren.
I’m on sabbatical during the Spring of 2022.
See this blog post for grad studies and postdoc opportunities at Harvard. See also our ML theory opportunities page.
See the Harvard ML Theory group website for our seminar and other activities in the theory of machine learning.
I am teaching this crypto in Fall 2021, and updating my intensive introduction to cryptography lecture notes. Comments are welcome as issues/pull requests on the GitHub repository.
I am working on a book on “Introduction to Theoretical Computer Science”. Comments are welcome as issues/pull requests on the GitHub repository.
I wrote a graduate textbook with Sanjeev Arora: Computational Complexity: A Modern Approach. I am currently writing an undergraduate textbook: Introduction to Theoretical Computer Science. I also wrote extensive notes on an intense introduction to cryptography and on the sum of squares algorithm (with David Steurer). I occasionally blog on the Windows on Theory blog and Tweet.
Some surveys and essays I wrote are below. See here for more of my less technical writing.
Work with what you’ve got, Nature Physics, January 21. (About experiments running the QAOA algorithm on nearterm intermediatescale noisy quantum devices (NISQ).
ML Theory with bad drawings and Puzzles of modern machine learning  blog posts.
How to use mathematical models for Covid19 (in Hebrew)  with Shachar Artzi, Janni Yuval, Mor Nitzan, and Neta Ravid.
The different forms of quantum computing skepticsm  blog post. See also pdf version
The Complexity of PublicKey Cryptography  survey/tutorial on the computational assumptions landscape of cryptogrpahy. Written in honor of Oded Goldreich’s 60th birthday.
Bayesianism, frequentism, and the planted clique, or do algorithms believe in unicorns?, April 2016. See also blog post on windows of theory blog and video of a talk at Northwestern.
Men in Computer Science  blog post, August 2017.
Hopes, Fears, and Software Obfuscation, Communications of the ACM, March 2016. See also preprint version and video of short interview.
Speaking about unspeakables, Harvard Lectures that Last 2016, February 2016, see also video of lecture.
Structure vs Combinatorics in Computational Complexity, Windows on Theory blog, October 2013. See also adapted version in the bulletin of the European Association for Theoretical Computer Science.
Truth vs. Proof  the Unique Games Conjecture and Feige’s Hypothesis, Windows on Theory blog, July 2012. See also adapted version in logic in computer science column of the bulletin of the European Association for Theoretical Computer Science.
My first publication: tip for Ultima IV game in Commodore Magazine, June 1988.
Here are some of the courses / lectures I (Co) taught (see here for all courses):
Harvard CS229br: Advanced topics in the theory of machine learning, Spring 2021
Harvard CS127: Cryptography, Fall 2021, Spring 2020, Spring 2018, Spring 2016.
Harvard CS121: Introduction to Theoretical Computer Science  Fall 2019, Fall 2018, Fall 2017.
Harvard CS229r: Physics and Computation Seminar, Fall 2018.
Harvard CS229r / MIT 6.S898: Proofs, beliefs and algorithms through the lens of Sum of Squares  Fall 2016  graduate course/seminar on the Sum of Squares algorithm.
Addis Coder summer course on algorithms and coding for high school students in Ethiopia.
Princeton COS 522  (graduate) Computational Complexity  Spring 2009
Princeton COS 598D  Mathematical Methods in Theoretical Computer Science  Spring 2008
Email: . For Harvard related mails (apart from DUS), please use Any emails related to my role as DUS should be sent to csdus@seas.harvard.edu.  
Please use or for reference letter or manuscript review requests respectively. (emails to these addresses are forwarded to my main inbox, but are also tagged appropriately so I don't lose track of them. Emails to the reference address are also forwarded to my faculty coordinator.)  
Upcoming office hours: (see all hours and schedule appointments)


Physical Location: Office 3.3096 in Harvard Allston SEC complex, 150 Western Avenue, Boston, MA.  
Mailing Address: Professor Boaz Barak, Harvard University SEAS, SEC Building Office 3.309, 150 Western Avenue, Boston, MA 02134  
Administrative assistant: Evelyn (Evie) SantanaNola, , santana@seas.harvard.edu  
Phone: (617) 4961537 (I prefer email) 