Hi! I'm Ryan Henry, an Assistant Professor of Computer Science in the School of Informatics, Computing, and Engineering at Indiana University Bloomington. My research explores the systems challenges of applied cryptography, with a particular emphasis on using cryptography to build secure systems that preserve the privacy of their users.
I'm looking for bright graduate students who share my interests in applied cryptography, cybersecurity, and online privacy. If you're such a student and you're looking for an advisor, then we should probably talk.
- INFO-I 231/CSCI-C 231: Introduction to the Mathematics of Cybersecurity (Spring 2018)
- INFO-I 538/CSCI-B 504: Introduction to Cryptography (Spring 2017)
- CSCI-B 609: Private Information Retrieval (Spring 2017)
- INFO-I 231: Introduction to the Mathematics of Cybersecurity (Spring 2016)
- INFO-I 538: Introduction to Cryptography (Fall 2015)
- INFO-I 538: Introduction to Cryptography (Spring 2015)
- Adithya Vadapalli (PhD; S18–present)
- Fattaneh Bayatbabolghani (Post doc; F18–present)
- Andrew Holland (PhD; F17–present)
- Swaminathan Vengalathur Ramesh (PhD; F16–present)
- Syed Mahbub Hafiz (PhD; F15–present)
I develop cryptographic techniques for preserving the privacy of users on the Internet. I'm also interested in applying cryptography to build tools to resist and circumvent online censorship, as well as in more theoretical matters related to how efficient cryptographic tools can be.
Practical Private Information Retrieval
Accountable Anonymity Systems
Efficient Zero-Knowledge Proofs
Solving Discrete Logarithms in CUDA
Ryan Henry, Amir Herzberg, and Aniket Kate: Blockchain Access Privacy: Challenges and Directions. In IEEE Security and Privacy Magazine: Special Issue on the Blockchain (to appear).
Syed Mahbub Hafiz and Ryan Henry: Querying for Queries: Indexes of Queries for Efficient and Expressive IT-PIR. In the 24th ACM Conference on Computer Communications Security (ACM CCS 2017), October–November 2017 (Dallas, TX). (Acceptance rate: 151/836 ≈ 18.1%)See the associated tech report: IACR 2017-825.
Bailey Kacsmar, Sarah Plosker, and Ryan Henry: Computing Low-Weight Discrete Logarithms. In the 24th Annual Conference on Selected Areas in Cryptography (SAC 2017), August 2016 (Ottawa, ON). (Acceptance rate: 23/66 ≈ 34.8%)See the associated tech report: IACR 2017-720.
Tariq Elahi and Ryan Henry: Privacy-preserving Anomaly Detection in Tor. In the Private Multiparty Maching Learning (PMPML 2016) – NIPS 2016 Workshop, December 2016 (Barcelona, Spain). (Acceptance rate: 20/? ≈ NaN%)
Ryan Henry: Polynomial Batch Codes for Efficient IT-PIR. In the Proceedings on Privacy Enhancing Technologies (PoPETS), Volume 2016(4), July 2016 (Berlin, Germany). (Acceptance rate: 51/189 ≈ 26.98%)See the associated tech report: IACR 2016-598.
Ryan Henry and Ian Goldberg: Thinking Inside the BLAC Box: Smarter Protocols for Anonymous Blacklisting. In the 12th ACM Workshop on Privacy in the Electronic Society (WPES 2013), November 2013 (Berlin, Germany). (Acceptance rate: 20/103 ≈ 19%)See the associated tech report: CACR 2013-08.
Ryan Henry and Ian Goldberg: Batch Proofs of Partial Knowledge. In the 11th International Conference on Applied Cryptography & Network Security (ACNS 2013), June 2013 (Banff, AB). (Acceptance rate: 43/150 ≈ 22%)
Ryan Henry, Yizhou Huang, and Ian Goldberg: One (Block) Size Fits All: PIR and SPIR with Variable-Length Records via Multi-Block Queries. In the 20th Annual Network & Distributed System Security Symposium (NDSS 2013), February 2013 (San Diego, CA). (Acceptance rate: 47/250 ≈ 18.8%)
Ryan Henry and Ian Goldberg: Solving Discrete Logarithms in Smooth-Order Groups with CUDA. In the 5th Workshop on Special-Purpose Hardware for Attacking Cryptographic Systems (SHARCS 2012), March 2012 (Washington, DC). (Acceptance rate: 9/? ≈ NaN%)See the associated tech report: CACR 2012-02.
Ryan Henry, Femi Olumofin, and Ian Goldberg: Practical PIR for Electronic Commerce. In the 18th ACM Conference on Computer Communications Security (ACM CCS 2011), October 2011 (Chicago, IL). (Acceptance rate: 60/429 ≈ 14.0%)See the associated tech report: CACR 2011-04.
Ryan Henry and Ian Goldberg: Extending Nymble-like Systems. In the 32nd IEEE Symposium on Security and Privacy (IEEE S&P 2011), May 2011 (Oakland, CA). (Acceptance rate: 34/306 ≈ 11.1%)See the associated tech report: CACR 2010-23.
Ryan Henry and Ian Goldberg: Formalizing Anonymous Blacklisting Systems. In the 32nd IEEE Symposium on Security and Privacy (IEEE S&P 2011), May 2011 (Oakland, CA). (Acceptance rate: 34/306 ≈ 11.1%)See the associated tech report: CACR 2010-24.