About us

We are Cryptology & Algorithm Lab and our leader is Professor Jae Hong Seo. Our main research interests are in cryptography especially zero-knowledge proof. Besides cryptography, we’re interested in artificial intelligence using deep learning such as face recognition and speaker recognition.

Annual News

  • (June 5, 2024) Professor Taeho Jung from the University of Notre Dame will visit C&A lab. He will give a lecture and discuss joint research.
    • Date & Place : 04:00 PM, June 5 / Natural Science building 702
    • Title : A Scalable Variant of Private Set Intersection
    • (For lecture abstract, click the arrow) Abstract: Private Set Intersection (PSI) is a primitive that allows a querier to learn whether there is an intersection between a query set and another set held by a server. This is a privacy-preserving protocol because the querier does not learn anything about the server’s set, and the server does not learn anything about the querier’s set either. FHE-based protocols have advantages such as post-quantum security and asynchrony, but they have the downside of low scalability. The scalability bottleneck lies in the multiplicative nature of the homomorphic circuit evaluated during the PSI protocol. We present an addition-based variant of PSI that overcomes this scalability limit such that the PSI can be run against hundreds of thousands of servers.
  • (May 31, 2023) The following paper has been accepted for publication in IWSEC 2023.
    • Hyeonbum Lee and Jae Hong Seo
      TENET : Sublogarithmic Proof, Sublinear Verifier Inner Product Argument without a Trusted Setup
  • (Apr 19, 2024) Hyeonbum Lee has been selected as a speaker for the submission proposal in the 6th ZKProof workshop in Berlin.
  • (Apr 11, 2024) Sunpill Kim is selected as the 1st Graduate Presidential Science Scholarship recipient. (Ph.D. student in the Department of Mathematics, 2 finalists selected)
  • (Mar 1, 2024) The following paper has been accepted as a poster at IEEE ICBC 2024.
    • Hyeonbum Lee, Kyuhwan Lee, Wenyi Tang, Shankha Shubhra Mukherjee, Jae Hong Seo, and Taeho Jung
      PrivHChain: Monitoring the Supply Chain of Controlled Substances with Privacy-Preserving Hierarchical Blockchain
  • (Feb 5, 2024) Chanwoo Hwang and Dongsoo Kim visit in the Singapore A*STAR to participate short-term research for top international students during five months. We wish their successful journeys to become good researchers!
  • (Feb 5, 2024) The following paper has been accepted for publication at IEEE TDSC.
    • Changhao Chenli, Wenyi Tang, Hyeonbum Lee, and Taeho Jung
      Fair2Trade: Digital Trading Platform Ensuring Exchange and Distribution Fairness

We share information with each other through various seminars/studies that support research capabilities every summer/winter vacation to enhance research and inquiry skills. Each season, the main topic changes and the schedule also changes accordingly. External personnel are also free to participate, and you can attend by filling out the form from above link.

23 Summer

Seminar Schedule - IVC
Date Time Place Presenter Topic Material Blog Post
6/27 01:00PM 701 Hyeonbum Lee Nova : Recursive Zero Knowledge Arguments from Folding Schemes(DOI)
7/11 07:00PM 702 Hyunjung Son SuperNova: Proving universal machine executions without universal circuits(DOI)
7/18 01:00PM 701 Seongae Baek Customizable constraint systems for succinct arguments(DOI)
8/1 01:00PM 751 Hyeonbum Lee Hypernova : Recursive arguments for customizable constraint systems(DOI)
8/8 702
8/14 01:00PM 701 Hyunjung Son Protostar : Generic Efficient Accumulation/Folding for Special-sound Protocols(DOI)

Deep Learning
Seminar Schedule - Deep Learning Paper
Date Time Place Presenter Topic Material Blog Post
7/12 10:00AM 702 Bora Jeong DeepFool: A simple and accurate method to fool deep neural networks (CVPR'16)(DOI)
Seunghun Paik Adversarial Examples Are Not Bugs, They Are Features (NIPS'19 Spotlight)(DOI)
7/19 10:00AM 702 Chanwoo Hwang Adversarial Patch (arXiv'17)(DOI)
Dongsoo Kim Efficient Decision-based Black-box Adversarial Attacks on Face Recognition (CVPR'19)(DOI)
7/26 10:00AM 702 Minsu Kim Universal adversarial perturbations (CVPR'17)(DOI)
8/2 10:00AM 702 Bora Jeong Iris Recognition (LINK) (LINK)
Seunghun Paik Understanding Adversarial Examples (LINK) (LINK)
8/9 10:00AM 702 Chanwoo Hwang What is Dataset Distillation? (LINK) (LINK)
8/16 10:00AM 702 Dongsoo Kim Predictive Coding
8/30 10:00AM TBA Hyeonkyu Kim Recurrent Neural Network
9/1 03:00PM TBA Minsu Kim Fuzzy Extractor

ZKP Basic
Seminar Schedule - ZKP Basic
Date Time Place Presenter Topic Material Blog Post
7/07 02:00PM 702 Junhee Cho proofs, interactive proofs, schwarz-zippel lemma, multilinear extension
7/14 10:00AM 702 Yunki Kim sumcheck protocol
7/21 02:00PM 702 Seongae Baek application of sum-check protocol
7/28 02:00PM 702 Seongae Baek GKR protocol
8/04 02:00PM 702 Junhee Cho
Yunki Kim
non-interactive proofs, random oracle model, fiat-shamir heuristic argument of knowledge, knowledge soundness
8/10 02:00PM 702 Yunki Kim zero-knowledge, sigma protocol

22-23 Winter

Deep Learning
Seminar Schedule - Deep Learning Paper
Date Time Place Presenter Topic
1/2 01:00PM 702 Seunghun Universal Hopfield Networks: A General Framework for Single-Shot Associative Memory Models
Dongsoo Towards Face Encryption by Generating Adversarial Identity Masks
1/16 01:00PM 702 Chanwoo SFace: Sigmoid-Constrained Hypersphere Loss for Robust Face Recognition
Seunghun Continual variational autoencoder learning via online cooperative memorization
1/26 10:00AM 702 Prof. Jaehong Seo Hopfield Network Summary
1/30 01:00PM 702 Dongsoo AnchorFace: Boosting TAR@FAR for Practical Face Recognition
Chanwoo Privacy-Preserving Face Recognition with Learnable Privacy Budgets in Frequency Domain
2/13 01:00PM 701 Seunghun Hyperspherical Consistency Regularization
Dongsoo CoupleFace: Relation Matters for Face Recognition Distillation
2/20 01:00PM 702 Chanwoo QuantFace: Towards lightweight face recognition by synthetic data low-bit quantization
Seunghun On the Relationship Between Variational Inference and Auto-Associative Memory
TBD TBD TBD Dongsoo UFace: An Unsupervised Deep Learning Face Verification System
Chanwoo Frontal-Centers Guided Face: Boosting Face Recognition by Learning Pose-Invariant Features

Computational Number Theory & Algebra
Seminar Schedule - Computational Number Theory & Algebra
Book : A computational Introductiobn to Numver Theory and Algebra second Edition
Date Time Place Topic
1/5 01:00PM 702 Chap. 1 ~ 4, Review on Number Theory and Integer Arithmetics
1/12 01:00PM 702 Chap. 8 ~ 9, Probabilistic Distributions and Algorithms on
1/19 01:00PM 702 Chap. 10 ~ 12, More Probabilistic Algorithms on (e.g. Miller-Rabin Test)
1/26 01:00PM 702 Chap. 6,7,13,14, Groups, Rings, Modules, and Vector Spaces
2/2 01:00PM 702 Chap. 16, More on Rings (e.g. Field Extension, PID, UFD, ...)
2/9 01:00PM 702 Chap. 17 ~ 18, Polynomial Arithmetics, and Linearly Generated Sequences
2/16 01:00PM 702 Chap. 19 ~ 20, Finite Fields, Algorithms for Finite Fields (e.g. Cantor-Zassenhaus Algorithm)
2/23 01:00PM 702 Chap. 15, 21, Dixon’s Method, Index Calculus Method, and AKS Algorithm

Seminar Schedule - Algorithm
Every Wednesday at 1pm

Zero Knowledge Proof
Seminar Schedule - Zero Knowledge Proof

Note that the contents of the seminar will be shared through the following blog post.


For any inquires, you can reach us via email: webmaster.cnalab@gmail.com