Jeremiah Blocki @Purdue (Publications)

Password Hashing

A New Connection Between Node and Edge Depth Robust Graphs. with Mike Cinkoske. ITCS 2021 [Full Version]
Computationally Data-Independent Memory Hard Functions. with Mohammad Hassan Ameri and Samson Zhou. ITCS 2020 [Full Version]
Approximating Cumulative Pebbling Cost is Unique Games Hard. with Seunghoon Lee and Samson Zhou. ITCS 2020 [Full Version]
Data-Independent Memory Hard Functions: New Attacks and Stronger Constructions. with Ben Harsha and Siteng Kang and Seunghoon Lee and Lu Xing and Samson Zhou. CRYPTO 2019 [Full Version]
Bandwidth-Hard Functions: Reductions and Lower Bounds. with Ling Ren and Samson Zhou. CCS 2018 [Full Version]
Sustained Space Complexity. with Joel Alwen and Krzysztof Pietrzak. EUROCRYPT 2018 [Full Version]
On the Economics of Offline Password Cracking. with Ben Harsha and Samson Zhou. 39th IEEE Symposium on Security & Privacy (S&P 2018). [Full Version]
On the Computational Complexity of Minimal Cumulative Cost Graph Pebbling. with Samson Zhou. Financial Crypto 2018 . [arXiv]
Just In Time Hashing. with Ben Harsha. 3rd IEEE European Symposium on Security and Privacy (EURO S&P 2018). [Full Version]
Practical Graphs for Optimal Side-Channel Resistant Memory-Hard Functions. with Joel Alwen and Ben Harsha. CCS 2017. Full Version
On the Depth-Robustness and Cumulative Pebbling Cost of Argon2i. with Samson Zhou. TCC 2017. [Full Version]
Depth-Robust Graphs and Their Cumulative Memory Complexity. with Joel Alwen and Krzysztof Pietrzak. EUROCRYPT 2017. [Full Version]
Towards Practical Attacks on Argon2i and Balloon Hashing. with Joel Alwen. EuroS&P 2017. [Full Version]
Efficiently Computing Data Independent Memory Hard Functions. with Joel Alwen. CRYPTO 2016. [Full Version]
Designing Proof of Human-work Puzzles for Cryptocurrency and Beyond. with Hong-Shen Zhou. TCC 2016-B. [Full Version]
CASH: A Cost Asymmetric Secure Hash Algorithm for Optimal Password Protection. with Anupam Datta. CSF 2016. [Full Version]
Client-CASH: Protecting Master Passwords against Offline Attacks. with Anirudh Sridhar. AsiaCCS 2016. [Full Version]

Coding Theory and Cryptography

Locally Decodable/Correctable Codes for Insertions and Deletions. with Alex Block, Elena Grigorescu, Shubhang Kulkarni and Minshen Zhou. FSTTCS 2020
On Locally Decodable Codes in Resource Bounded Channels. with Shubhang Kulkarni and Samson Zhou. ITC 2020 [Full Version]
Relaxed Locally Correctable Codes in Computationally Bounded Channels. with Venkata Gandikota, Elena Grigorescu and Samson Zhou. 2019 IEEE International Symposium on Information Theory (ISIT 2019). [Full Version] [ICALP 2018 Brief Announcement]

Usable and Secure Human Authentication

Surviving in the Digital Environment: Does Survival Processing Provide an Additional Memory Benefit to Password Generation Strategies? with Isis Chong, Robert Proctor and Ninghui Li. Journal of Applied Research in Memory and Cognition 2020 [DOI]
Towards Human Computable Passwords. with Manuel Blum, Anupam Datta and Santosh Vempala. ITCS 2017. [arXiv] [Password Cracking Challenge]
Spaced Repetition and Mnemonics Enable Recall of Multiple Strong Passwords. with Saranga Komanduri, Lorrie Cranor and Anupam Datta. NDSS 2015. [Full Version]
Press: ZDNet, Kapersky
GOTCHA Password Hackers! with Manuel Blum and Anupam Datta. AISec 2013. [Full Version] [GOTCHA Challenge]
Press: ArsTechnica, Slashdot, The Tartan and an inaccurate article from MIT Technology Review
Naturally Rehearsing Passwords. with Manuel Blum and Anupam Datta. ASIACRYPT 2013. [Full Version]
Press: Scientific American, ScienceDaily, CMU
Optimizing Password Composition Policies. with Saranga Komanduri, Ariel Procaccia and Or Sheffet. EC 2013. [Full Version]

Privacy Preserving Data Analysis

Locally Differentially Private Protocols for Frequency Estimation. with Tianhao Wang, Ninghui Li and Somesh Jha. USENIX 2017. Full Version
Differentially Private Password Frequency Lists: Or, How to release statistics from 70 million passwords (on purpose). with Anupam Datta and Joseph Bonneau. NDSS 2016. [Full Version] [Yahoo! Password Frequency Corpus]
Press: CMU, Science Newsline
Differentially Private Data Analysis of Social Networks via Restricted Sensitivity. with Avrim Blum, Anupam Datta and Or Sheffet. ITCS 2013. [Full Version]
The Johnson-Lindenstrausss Transform Itself Preserves Differential Privacy. with Avrim Blum, Anupam Datta and Or Sheffet. FOCS 2012. [Full Version]
Resolving the Complexity of Some Data Privacy Problems. with Ryan Williams. ICALP 2010. [Full Version]

Game Theory and Security

Bicycle Attacks Considered Harmful: Quantifying the Damage of Widespread Password Length Leakage. with Ben Harsha, John Springer and Melissa Dark. Computers & Security 2020 (to appear) [Full Version] [LinkedIn Password Frequency Corpus]
An Economic Model for Quantum Key-Recovery Attacks against Ideal Ciphers. with Ben Harsha. WEIS 2020 [Full Version]

Audit Games with Multiple Defender Resources

AAAI 2015

Full Version

Audit Games. with Nicolas Christin, Anupam Datta, Ariel Procaccia and Arunesh Sinha. IJCAI 2013. [Full Version]
Adaptive Regret Minimization in Bounded-Memory Games. with Nicolas Christin, Anupam Datta and Arunesh Sinha. GameSec 2013. [Invited Paper] [Full Version]
Audit Mechanisms for Privacy Protection in Healthcare Environments. with Nicolas Christin, Anupam Datta and Arunesh Sinha. HealthSec 2011. [position paper]
Regret Minimizing Audits: A Learning-Theoretic Basis for Privacy Protection. with Nicolas Christin, Anupam Datta and Arunesh Sinha. CSF 2011. [Full Version]