Wonseok’s Homepage
Hi!
I am Wonseok Choi (최원석, 崔元碩), an assistant professor in the EECS department at DGIST, Korea.
If you’re interested in working with me as a PhD student or postdoc, please drop me an email.
I am working on multiple research topics, focusing on two main areas:
security analysis/proof of algorithms and protocols and
designing algorithms and protocols for multi-party computation, blockchain, etc.
More importantly, I aim to establish the precise security model or requirements for each problem, define appropriate notions, and conduct a thorough analysis. Previously, I spent a great time as a postdoc at Purdue University and GeorgiaTech hosted by Vassilis Zikas. Before that, I was a research fellow at KIAS (Korea Institute for Advanced Study) for half a year, mentored by Changmin Lee.
I received my Ph.D. from KAIST (Korea Advanced Institute of Science and Technology), where I was fortunate to be advised by Jooyoung Lee. During my Ph.D., I focused on provable security in symmetric-key cryptography: improving security analyses of several symmetric-key algorithms and proposing new constructions such as pseudorandom functions, message authentication codes, and authenticated encryptions with associated data.
Before studying cryptography, I majored in mathematics at KAIST for my master’s and bachelor’s degrees. I still enjoy solving math quizzes!
My research interests include
Cryptography including symmetric-key, public-key, primitive design, and provable security
Secure multi-party computation and blockchain
Related topics in cryptology and mathematics
Latest News
(May. 2025) I have become an assistant professor at DGIST. :)
(Apr. 2025) My paper on designing new AEADs dedicated to short input lengths has been accepted to TCHES2025(3)/CHES2025!
(Aug. 2024) My paper on tight security of nonce-misuse resistant MACs with KAIST CRYPT LAB has been accepted at ASIACRYPT 2024.
(Jul. 2024) I appreciate my co-authors for the work on efficient tweakable block ciphers accepted to ProvSec 2024.
(May. 2024) My paper proposing new TBC-based AEADs has been accepted to DCC with my great colleagues in KAIST CRYPT LAB.
Publication List
Alexandre Adomnic\u{a}i, Wonseok Choi, Yeongmin Lee, Yusuke Naito, and Kazuhiko Minematsu, “Cymric: Short-tailed but Mighty”, TCHES 2025(3)/CHES 2025, to appear.
Wonseok Choi, Jooyoung Lee, and Yeongmin Lee, “Tight Security of Double-Block Nonce-Based MACs”, ASIACRYPT 2024.
Ritam Bhaumik, Wonseok Choi, Avijit Dutta, Cuauhtemoc Mancillas Lopez, Hrithik Nandi, and Yaobin Shen, “Efficient Variants of TNT with BBB Security”, ProvSec 2024.
Wonseok Choi, Seongha Hwang, Byeonghak Lee, and Jooyoung Lee, “ZLR: A Fast Online Authenticated Encryption Achieving Full Security”, DCC 2024.
Ritam Bhaumik, Bishwajit Chakraborty, Wonseok Choi, Avijit Dutta, Jérôme Govinden, and Yaobin Shen, “The Committing Security of MACs with Applications to Generic Composition”, CRYPTO 2024.
Wonseok Choi, Jooyoung Lee, and Yeongmin Lee, “Building PRFs from TPRPs: Beyond the Block and the Tweak Length Bounds”, ToSC 2024(1) / FSE 2024.
Yu Long Chen, Wonseok Choi, and Changmin Lee, “Improved Multi-User Security Using the Squared-Ratio Method”, CRYPTO 2023.
Wonseok Choi, Hwigyeom Kim, Jooyoung Lee, and Yeongmin Lee, “Multi-User Security of the Sum of Truncated Random Permutations”, ASIACRYPT 2022.
Wonseok Choi, Byeonghak Lee, Jooyoung Lee, and Yeongmin Lee, “Toward a Fully Secure Authenticated Encryption Scheme From a Pseudorandom Permutation”, ASIACRYPT 2021.
Wonseok Choi, Akiko Inoue, Byeonghak Lee, Jooyoung Lee, Eik List, Kazuhiko Minematsu, and Yusuke Naito, “Highly Secure Nonce-based Macs from the Sum of Tweakable Block Ciphers”, ToSC 2020(4) / FSE 2022.
Wonseok Choi, Byeonghak Lee, Yeongmin Lee, and Jooyoung Lee, “Improved Security Analysis for Nonce-based Enhanced Hash-then-Mask MACs”, ASIACRYPT 2020.
Jincheol Ha, Seongkwang Kim, Wonseok Choi, Jooyoung Lee, Dukjae Moon, Hyojin Yoon, and Jihoon Cho, “Masta: An HE-friendly Cipher Using Modular Arithmetic”, IEEE Access 2020.
Wonseok Choi, Byeonghak Lee, and Jooyoung Lee, “Indifferentiability of Truncated Random Permutations”, ASIACRYPT 2019.
Editorial Board / Program Committee
ToSC 2025/2026 / FSE 2026
ISC 2025
ToSC 2024/2025 / FSE 2025
ASIACRYPT 2024
ISC 2024
ToSC 2023/2024 / FSE 2024
Talks
“On Overidealizing Ideal Worlds: Xor of Two Permutations and its Applications”
Invited Talk at Radbound University, Nijmegen (the Netherlands), Mar. 2024.
Invited Talk at DESILO, Seoul (Korea), Dec. 2023.
Invited Talk at ASK 2023, Guangzhou (China), Dec. 2023.
“Improved Multi-User Security Using the Squared-Ratio Method”
CRYPTO 2023, Santa Barbara (CA), Aug. 2023.
Athecrypt 2023, Athens (Greece), May. 2023.
Invited Talk at NEC Core Technology Forum, Kanagawa (Japan), Dec. 2022.
“Multi-User Security of the Sum of Truncated Random Permutations”
ASIACRYPT 2022, Taipei (Taiwan), Dec. 2022.
2022 Global KMS International Conference, Seoul (Korea), Oct. 2022.
“Building PRFs from TPRPs: Beyond the Block and the Tweak Length Bounds”
FSE 2024, Leuven (Belgium), Mar. 2024.
2022 KMS Spring Meeting, Online, Apr. 2022.
Security@KAIST Student Research Presentation, Online, Nov. 2021.
National Cryptography Contest Awards, Seoul (Korea), Oct. 2021.
“Indifferentiability of Truncated Random Permutations”
ASIACRYPT 2019, Kobe (Japan), Dec. 2019.
Invited Talk at Korea Cryptography Forum Workshop, Gyeonggi (Korea), May. 2019.
National Cryptography Contest Awards, Seoul (Korea), Nov. 2018.
Reviews
Review: FSE 2025 (ToSC 2024/2025), ASIACRYPT 2024, ISC 2024, FSE 2024 (ToSC 2023/2024)
Subreview: CRYPTO 2024, EUROCRYPT 2024, ACNS 2023, EUROCRYPT 2023, and LATINCRYPT 2023
External Review: FSE 2022, ASIACRYPT 2020, ASIACRYPT 2019, ICISC 2018, and ProvSec 2018
Last Update: 12/MAY/2025