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

  • (Jul 03, 2025) The following paper has been accepted for presentation at ACM CCS 2025.
    • Intak Hwang, Hyeonbum Lee, Jinyeong Seo, Yongsoo Song
      Practical Zero-Knowledge PIOP for Maliciously Secure Multiparty Homomorphic Encryption
  • (Jun 26, 2025) The following paper has been accepted for presentation at ICCV 2025.
    • Sunpill Kim, Seunghun Paik, Chanwoo Hwang, Dongsoo Kim, Junbum Shin, and Jae Hong Seo
      IDFace: Face Template Protection for Efficient and Secure Identification
  • (Jun 22, 2025) The following paper has been accepted for presentation at ESORICS 2025.
    • Jaehwan Park, Hyeonbum Lee, Junbeom Hur, Jae Hong Seo and Doowon Kim
      UTRA: Universal Token Reusability Attack and Token Unforgeable Delegatable Order-Revealing Encryption
  • (Jun 5, 2024) Doctor Mahdi Sedaghat from COSIC, KU Leuven, and founder of Soundness Labs will visit C&A lab. He will give a lecture and discuss joint research.
    • Date & Place : 01:00 PM, May 20 / Natural Science building 701
    • Title : Translating Zero-Knowledge Research into Real-World Web3 Solutions: zkLogin and more
      • (For lecture abstract, click the arrow) Abstract: In this talk, I will share some of my recent works on bringing zk to real-world usecases. As the main part of the talk, I will discuss how zkLogin has simplified users' onboarding process by using identity tokens from platforms like Google or Facebook to authenticate transactions. Instead of managing new secrets, users can sign in with their existing accounts, and zero-knowledge proofs ensure that the link between a user’s off-chain and on-chain identity stays hidden. Since its launch on the Sui blockchain, zkLogin has processed over 7 million zkLogin-signed transactions, containing around 2.5 million unique Zero-Knowledge Proofs (as of March 17, 2025), making it one of the most widely used zkApp. Additionally I will cover some extra use-cases like targeted Airdrops.
  • (Apr 8, 2024) Dongsoo Kim, a member of our lab, will be giving a talk at the Hanyang University Mathematics Colloquium on the following topic.
    • Date & Place : 04:00 PM, Apr 8 / Natural Science building B119
    • Title : Certifiable robustness: Theoretically guaranted defence method against to adversarial attack on deep learning model
  • (Feb 27, 2025) The following project supported by Korea Institute of Information Security & Cryptology (KIISC) has started.
    • Adversarial Attacks and Security Analysis on Commercial Face Recognition APIs
  • (Feb 10, 2025) Ph.D. Heewon Chung, a former postdoctoral researcher from our lab, has been appointed as an Assistant Professor in the Department of Software Engineering at Jeonbuk National University (전북대학교 소프트웨어공학과) in South Korea.
  • (Jan 1, 2025) The following paper has been accepted for publication at Pattern Recognition.
    • Sunpill Kim, Hoyong Shin, and Jae Hong Seo
      Deep Face Template Protection in the Wild

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

IVC
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)
7/6
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)
7/25
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)
TBD


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


Algorithm
Seminar Schedule - Algorithm
Every Wednesday at 1pm


Zero Knowledge Proof
Seminar Schedule - Zero Knowledge Proof
TBD

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

Contact


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