Email:  
For Harvard (non DUS) related mails, please use For DUS related mails use csdus@seas.harvard.edu.  
Please use or for reference letter or manuscript review requests respectively.  
Quick Links: 
Intro TCS  Complexity book  ML Theory  CS 121  CS 127  SOS notes 
About me: 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. See also short biography and CV.
DUS: 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: Trustee of the Computational Complexity Foundation. 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 co organizer of the Harvard Machine Learning Theory seminar. Co organizer of Addis Coder. See my CV for past activities.
Current students: Zhixian Lei, Yueqi Sheng, ChiNing Chou, Prayaag Venkat, Preetum Nakkiran (coadvised with Madhu Sudan), Beatrice Nash (coadvised with Misha Lukin).
Former students: Sharon Goldberg (co advised with Jennifer Rexford), David Xiao (co advised with Avi Wigderson), Mohammad Mahmoody, Moritz Hardt.
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 awards CCF 1565264 and CNS 1618026 and a Simons Investigator Fellowship. 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.
See also my curriculum vitae and brief bio. I also occasionally blog and tweet.
Personal: I am married to Ravit Barak and father to Alma and Goren.
Starting March 18th, I will be working remotely as part of Harvard’s (and the world’s) efforts to suppress COVID19. See Harvard FAQ and specific information for CS undergraduates. All my office hours will be held remotely via zoom. The defaults are listed in this page but if it doesn’t work for you due to time zone differences please contact me.
I am working on a new 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 the sum of squares algorithm (with David Steurer). I occasionally blog on the Windows on Theory blog.
Some surveys and essays I wrote are below. See here for more of my less technical writing.
Puzzles of modern machine learning  blog post.
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 CS127: Cryptography, 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 (in Maxwell Dworkin 329): (see all hours and schedule appointments)


Physical Location: Office 329 (third floor) in MaxwellDworkin Hall, 33 Oxford Street, Cambrdige.  
Mailing Address: Professor Boaz Barak, MaxwellDworkin Hall Room 329, 33 Oxford Street, Cambridge, MA 02138.  
Administrative assistant: Evelyn (Evie) SantanaNola, , santana@seas.harvard.edu  
Phone: (617) 4961537 (I prefer email) 