Jeremiah Blocki

Microsoft Research

E-mail:       [jblocki AT cs DOT cmu DOT edu]

Present: I am a postdoc at Microsoft Research New England Lab.

Future: I am excited to join the Computer Science Department at Purdue University next fall (2016) as an assistant professor.

Past: I completed my PhD at Carnegie Mellon University in 2014. My thesis focused on Usable and Secure Human Authentication. I was fortunate to be co-advised by Manuel Blum and Anupam Datta, and I was thankful to be supported by a NSF Graduate Research Fellowship. I also completed my undergraduate studies at Carnegie Mellon University where I double majored in Computer Science and Mathematics.  After I completed my PhD I spent one year as a postdoc under the supervision of Anupam Datta, and I spent the several months as a research fellow at the Simons Institute for Theoretical Computing during their summer Cryptography program.

Research Interests: I am especially interested in developing usable authentication protocols for humans. Are there easy ways for humans to create and remember multiple strong passwords? Can we design secure cryptographic protocols that are so simple that can be run by a human?

Other Research Interests: At a high level I am a theoretical computer scientist who is interested in applying fundamental ideas from computer science to address practical problems in usable privacy and security.   Is it possible for data curator to provide useful answers to questions about a social network while preserving differential privacy? I am also interested in game theory and learning theory and their applications to practical security problems like auditing. Recently I have also taken particular interest in the design and analysis of password hash functions.

Thesis: Usable Human Authentication: A Quantitative Treatment

Publications:

Usable and Secure Human Authentication:

Spaced Repetition and Mnemonics Enable Recall of Multiple Strong Passwords. With Saranga Komanduri, Lorrie Cranor and Anupam Datta. NDSS 2015. [arXiv] [Slides]

Press: ZDNet, Kapersky

GOTCHA Password Hackers! With Manuel Blum and Anupam Datta. AISEC 2013. [Paper] [arXiv] [Slides] [GOTCHA Challenge]

                        Press: ArsTechnica, Slashdot, Salon, MIT Technology Review (Warning: Article is Inaccurate)

Naturally Rehearsing Passwords. With Manuel Blum and Anupam Datta. ASIACRYPT 2013 [arXiv] [Slides]

                        Press: Scientific American, Science Daily, CMU

Optimizing Password Composition Policies. With Saranga Komanduri, Ariel Procaccia, and Or Sheffet. EC 2013. [arXiv] [Slides]

Game Theory and Security:

Audit Games with Multiple Defender Resources. Nicolas Christin, Anupam Datta, Ariel Procaccia and Arunesh Sinha. AAAI 2015 (to appear). [arXiv]

              Adaptive Regret Minimization in Bounded-Memory Games. With Nicolas Christin, Anupam Datta and Arunesh Sinha. GameSec 2013. [Invited Paper] [Paper] [arXiv] [Slides]

Audit Games. With Nicolas Christin, Anupam Datta, Ariel Procaccia and Arunesh Sinha. IJCAI 2013. [arXiv]

Audit Strategies for Provable Risk Management and Accountable Data Governance. With Anupam Datta, Nicolas Christin and Arunesh Sinha. GameSec 2012. [Paper]

Audit Mechanisms for Privacy Protection in Healthcare Environments. With Anupam Datta, Nicolas Christin and Arunesh Sinha. HealthSec 2011. [Position Paper]

Regret Minimizing Audits: A Learning-Theoretic Basis for Privacy Protection. WithAnupam Datta, Nicolas Christin and Arunesh Sinha. CSF 2011. [Paper]

Privacy Preserving Data Analysis:

Differentially Private Password Frequency Lists. With Anupam Datta and Joseph Bonneau. NDSS 2016 (to appear).

Differentially Private Data Analysis of Social Networks via Restricted Sensitivity.y. With Avrim Blum, Anupam Datta, and Or Sheffet. ITCS 2013. [arXiv] [Slides]

The Johnson-Lindenstrauss transform itself preserves differential privacy. With Avrim Blum, Anupam Datta, and Or Sheffet (lead author). FOCS 2012. [arXiv]

Resolving the Complexity of Some Data Privacy Problems. With Ryan Williams. ICALP 2010. [arXiv] [Slides]

Working Papers:

     Designing Proof of Human-work Puzzles for Cryptocurrency. With Hong-Sheng Zhou.

CASH: A Cost Asymmetric Secure Hash Algorithm for Optimal Password Protection. With Anupam Datta. [arXiv]

Human Computable Passwords. With Manuel Blum, Anupam Datta and Santosh Vempala. [arXiv] [Short Talk] [Long Talk] [Challenge]

Set Families with Low Pairwise Intersection. With Calvin Beideman. [arXiv]

Talks:

• Human Computable Passwords [Slides]

• Usable and Secure Password Management [Slides]

• GOTCHA Password Hackers[Slides]

• Differentially Private Data Analysis of Social Networks via Restricted Sensitivity [Slides]

• Adaptive Regret Minimization in Bounded-Memory Games[Slides]

• Resolving the Complexity of Some Data Privacy Problems [Slides]

• K-Anonymity [Slides

Program Committes:

• Workshop on Privacy in the Electronic Society (PC 2014)
• Passwords (PC 2015)
• Security and Cryptography for Networks (PC 2016)

Teaching

[CMU, Spring 2012] TA. 15-453 Formal Languages, Automata and Computability. (Instructor: Lenore Blum)

[CMU, Fall 2010] Head TA. 15-451 Algorithms. (Instructor: Manuel Blum)

[CMU, Fall 2008] TA. 15-859P Introduction to Theoretical Cryptography. (Instructor: Manuel Blum)

[CMU, Spring 2008] TA. 15-251 Great Theoretical Ideas in Computer Science. (Instructor: Luis von Ahn)

Undergraduate Work:

Senior Research Thesis: Direct Zero-Knowledge Proofs [Extended Abstract]

The Turing Machine Kernel Is Not Computable [Blog Post]

The Computational Complexity of K_n [Slides]

Personal Life:

I am happy to be married to my beautiful wife Heather! We have two young boys Isaiah and Noah.

My Church

I am a huge fan of Pitt basketball and football, the Penguins, and the Steelers. It has also been exciting to see the Pirates play well in recent years! I enjoy playing basketball, Frisbee, softball, and most other sports that mankind has invented.