🧠 🍕 🌯 Blocki’s Lab Lunch

Welcome to our lab’s informal talk series, organized by professor Jeremiah Blocki!
We meet every week in one of the LWSN computer science building conference rooms (or sometimes via Zoom).

📅 Time: Fridays, 12:00 PM 📍 Location: LWSN 1168

🧪 About the Blocki’s Lab Lunch

The Blocki’s Lab Lunch at Purdue University explores the theoretical foundations of cryptography, privacy, usable security and complexity theory, focusing on how to design algorithms and protocols that achieve strong security guarantees with practical efficiency. Our research spans topics such as memory-hard functions, differential privacy, (amortized) locally decodable codes, and secure password systems, combining tools from theoretical computer science, information theory, and applied cryptography. Recent publications from the lab have introduced advances in provably memory-hard proofs of work, differentially private compression, conditional encryption, quantum reversibility and graph pebbling. Through our weekly Lab Lunch Talks, we share new results, discuss ongoing projects, and foster collaboration among students and researchers interested in the mathematics of security and the limits of efficient computation.

📅 Upcoming and Past Talks

Srping 2026

Date	Speaker	Title	Materials
Jan 23, 2026	Blake	Paper title: How to Record Quantum Queries, and Applications to Quantum Indifferentiability. By [Mark Zhandry]	[Link to the Paper]
Jan 16, 2026	Hadas Zeilberger (Yale University)	Error-Correcting Codes That Enable Efficient SNARKs	[Video-Simons Institute]

Fall 2025

Date	Speaker	Title	Materials
Dec 12, 2025	Blake	–	–
Dec 05, 2025	No Lab Lunch (TCC conference)	–	–
Nov 28, 2025	No Lab Lunch (Thanksgiving)	–	–
Nov 21, 2025	Seunghoon Lee	Differentially Private Compression and the Sensitivity of LZ77 (TCC practice talk-Zoom)	Full Version
Nov 14, 2025	Nathan Smearsoll	Provably Memory-Hard Proofs of Work With Memory-Easy Verification (TCC practice presentation)	Full Version
Nov 07, 2025	Blake Holman	The Impact of Reversibility on Parallel Pebbling.	Full Version
Oct 31, 2025	Justin Zhang	Pseudorandom Coding and Its application in Watermarking the output texts generated by LLMs	–
Oct 24, 2025	Jeremiah Blocki, Blake Holman, Nathan Smearsoll	Research-related discussion and collaboration	–
Oct 17, 2025	TBD	–	–
Oct 10, 2025	STOC25 talk: Bhaskar Roberts, Aparna Gupte	Quantum One-Time Programs, Revisited	Video
Sep 26, 2025	EuroCrypt25 Talk: Adi Shamir	Polynomial Time Cryptanalytic Extraction of Deep Neural Networks in the Hard-Label Setting.	Video (33:35)
Sep 19, 2025	Justin Zhang	Amortized Locally Decodable Codes for Insertions and Deletions.	Full Version
Sep 12, 2025	Nathan Smearsoll	Provably Memory-Hard Proofs of Work With Memory-Easy Verification.	Full Version

🎯 Research Highlights and News

✨ Our lab’s ongoing projects combine deep theoretical insights with practical cryptographic design.
Here are a few themes we’re currently exploring:

quantum reversibility and graph pebbling— lower bound of on the quantum reversible cumulative pebbling cost. —> accepted in Eurocrypt25 Full Version
Memory-Hard Functions & Proofs of Work — designing puzzles that are provably costly to compute yet efficient to verify. —> accepted in TCC25 Full Version
Differential Privacy & Compression — developing algorithms that preserve data utility while protecting individual privacy. —> accepted in TCC25 Full Version
(Amortized) Locally Decodable Codes — creating error-correcting schemes that balance robustness and efficiency in modern data systems. —> accepted in ISIT25 Full Version, and ITCS25 Link
Conditional Encryption — public key cryptographic scheme which conditionally encrypts a payload message given ciphertext of an unknown message and a control message nunder a binary predicate. —> accepted in CCS24 Full Version.

💬 We welcome collaborations, reading group suggestions, and spontaneous “chalk-talk” ideas over lunch! contact: mameriek[at]purdue.edu

This site hosts the Blocki Lab’s seminar schedule, research highlights, and discussion summaries.