CRYPT LAB

Welcome! Our lab studies provable security in symmetric cryptography: we design various modes of operation such as authenticated encryption modes and accordion ciphers and prove their security. Furthermore, we also explore post-quantum cryptography based on symmetric primitives.

Publication

Refereed Conference Papers

• 1. Extending Accordion Security for Tighter Reduction to AE Security. W. Chung, S. Hwang, S. Kim, B. Lee and J. Lee.  Asiacrypt 2026, to appear.

  2. Addition-Efficient MDS Matrices from Superconcentrators. J. Lee, S. Park and M. Son.  Asiacrypt 2026, to appear.

  3. Security of NIST SP800-90A Hash-based DRBGs in the Seedless Model. W. Chung, S. Hwang, B. Lee, S. Kim and J. Lee. Euro S&P 2026, pp.1-22, IEEE, 2026.

  4. Refined TFHE Leveled Homomorphic Evaluation and Its Application. R. Wan, J. Ha, X. Shen, X. Lu, C. Chen, K. Wang and J. Lee. ACM CCS 2025, pp.2309-2323, ACM, 2025.

  5. Enhancing Provable Security and Efficiency of Permutation-based DRBGs. W. Chung, S. Hwang, H. Kim and J. Lee. Crypto 2025 (Part V), LNCS 16004, pp.467-496, Springer, 2025.

  6. Polocolo: A ZK-Friendly Hash Function Based on S-boxes Using Power Residues. J. Ha, S. Hwang, J. Lee, S. Park and M. Son. Eurocrypt 2025 (Part IV), LNCS 15604, pp.303-332, Springer, 2025.

  7. Making GCM Great Again: Toward Full Security and Longer Nonces. W. Chung, S. Hwang, S. Kim, B. Lee and J. Lee. Eurocrypt 2025 (Part I), LNCS 15601, pp.33-61, Springer, 2025.

  8. Provable Security of Linux-DRBG in the Seedless Robustness Model. W. Chung, H. Kim, J. Lee and Y. Lee.  Asiacrypt 2024 (Part VI), LNCS 15489, pp.461-490, Springer, 2024.

  9. Toward Full n-bit Security and Nonce Misuse Resistance of Block Cipher-based MACs. W. Choi, J. Lee and Y. Lee.  Asiacrypt 2024 (Part IX), LNCS 15492, pp.251-279, Springer, 2024.

  10. AIM: Symmetric Primitive for Shorter Signatures with Stronger Security. S. Kim, J. Ha, M. Son, B. Lee, D. Moon, J. Lee, S. Lee, J. Kwon, J. Cho, H. Yoon, and J. Lee. ACM CCS 2023, pp.401-415, ACM, 2023. 

  11. XOCB: Beyond-Birthday-Bound Secure Authenticated Encryption Mode with Rate-One Computation. Z. Bao, S. Hwang, A. Inoue, B. Lee, J. Lee, and K. Minematsu. Eurocrypt 2023 (Part IV), LNCS 14007, pp.532-561, Springer, 2023.

  12. Multi-User Security of the Sum of Truncated Random Permutations. W. Choi, H. Kim, J. Lee and Y. Lee.  Asiacrypt 2022 (Part II), LNCS 13792, pp.682-710, Springer, 2022.

  13. Rubato: Noisy Ciphers for Approximate Homomorphic Encryption. J. Ha, S. Kim, B. Lee, J. Lee and M. Son. Eurocrypt 2022 (Part I), LNCS 13275, pp.581-610, Springer, 2022.

  14. Transciphering Framework for Approximate Homomorphic Encryption. J. Cho, J. Ha, S. Kim, B. Lee, J. Lee, J.Lee, D. Moon and H. Yoon. Asiacrypt 2021 (Part III), LNCS 13092, pp.640-669, Springer, 2021.

  15. Toward a Fully Secure Authenticated Encryption Scheme From a Pseudorandom Permutation. W. Choi, B. Lee, J. Lee and Y. Lee. Asiacrypt 2021 (Part III), LNCS 13092, pp.407-434, Springer, 2021.

  16. Improved Security Analysis for Nonce-based Enhanced Hash-then-Mask MACs. W. Choi, B. Lee, Y. Lee and J. Lee. Asiacrypt 2020 (Part I), LNCS 12491, pp.697-723, Springer, 2020.

  17. Tight Security Bounds for Double-block Hash-then-Sum MACs. S. Kim, B. Lee and J. Lee. Eurocrypt 2020 (Part I), LNCS 12105, pp.435-465, Springer, 2020.

  18. FPL: White-Box Secure Block Cipher Using Parallel Table Look-Ups. J. Kwon, B. Lee, J. Lee and D. Moon. CT-RSA 2020, LNCS 12006, pp.106-128, Springer, 2020.

  19. Indifferentiability of Truncated Random Permutations. W. Choi, B. Lee and J. Lee. Asiacrypt 2019 (Part I), LNCS 11921, pp.175-195, Springer, 2019.  (Acceptance rate=23.1% )

  20. Tweakable Block Ciphers Secure Beyond the Birthday Bound in the Ideal Cipher Model.  B. Lee and J. Lee. Asiacrypt 2018 (Part I), LNCS 11272, pp.305-335, Springer, 2018.

  21. Provable Security of (Tweakable) Block Ciphers Based on Substitution-Permutation Networks.  B. Cogliati, Y. Dodis, J. Katz, J. Lee, J. Steinberger, A. Thiruvengadam and Z. Zhang. Crypto 2018 (Part I), LNCS 10991, pp.722-753, Springer, 2018.

  22. An Efficient Affine Equivalence Algorithm for Multiple S-Boxes and a Structured Affine Layer.  JH. Cheon, H. Hong, Joohee Lee and Jooyoung Lee. SAC 2016, vol 10532, pp.299-316, Springer, 2017.

  23. Relaxing Full-Codebook Security: A Refined Analysis of Key-Length Extension Schemes. P. Gazi, J. Lee, Y. Seurin, J. Steinberger, S. Tessaro. FSE 2015, LNCS 9054, pp.319-341, Springer, 2015.

  24. Minimizing the Two-Round Even-Mansour Cipher. S. Chen, R. Lampe, J. Lee, Y. Seurin and J. Steinberger. Crypto 2014 (Part I), LNCS 8616, pp.39-56, Springer, 2014.

  25. The Security of Multiple Encryption in the Ideal Cipher Model. Y. Dai, J. Lee, B. Mennink and J. Steinberger. Crypto 2014 (Part I), LNCS 8616, pp.20-38, Springer, 2014.

  26. Towards Key-Length Extension with Optimal Security: Cascade Encryption and Xor-cascade Encryption. J. Lee. Eurocrypt 2013, LNCS 7881, pp.405-425, Springer, 2013. 

  27. Provable Security of the Knudsen-Preneel Compression Functions. J. Lee. Asiacrypt 2012, LNCS 7658, pp.504-525, Springer, 2012.

  28. The Preimage Security of Double-Block-Length Compression Functions. F. Armknecht, E. Fleischmann, M. Krause, J. Lee, M. Stam, J. Steinberger. Asiacrypt 2011, LNCS 7073, pp.233-251, Springer, 2011.

  29. The Collision Security of Tandem-DM in the Ideal Cipher Model. J. Lee, M. Stam and J. Steinberger. Crypto 2011, LNCS 6841, pp.561-577, Springer, 2011.

  30. MJH: A Faster Alternative to MDC-2. J. Lee and M. Stam. CT-RSA 2011, LNCS 6558, pp.213-236, Springer, 2011.

  31. Multi-property-preserving Domain Extension Using Polynomial-based Modes of Operation. J. Lee and J. Steinberger. Eurocrypt 2010, LNCS 6110, pp.573-596, Springer, 2010.

  32. Vulnerability of an RFID Authentication Protocol Proposed at SecUbiq 2005. D. Kwon, D. Han, J. Lee and Y. Yeom. EUC 2006 , LNCS 4097, pp.262-270, Springer, 2006.

  33. A Set-covering Approach for Modeling Attacks on Key Predistribution in Wireless Sensor Networks. P. Tague, J. Lee and R. Poovendran. ICISIP 2005, pp.254-259, 2005.

  34. Tree-based Key Distribution Patterns. J. Lee and D. R. Stinson. SAC 2005, LNCS 3897, pp.189-204, Springer, 2005.

  35. A Combinatorial Approach to Key Predistribution for Distributed Sensor Networks. J. Lee and D. R. Stinson. IEEE WCNC 2005, pp.1200-1205 (Vol.2), 2005.

  36. Deterministic Key Predistribution Schemes for Distributed Sensor Networks. J. Lee and D. R. Stinson. SAC 2004, LNCS 3357, pp.294-307, Springer, 2004.

Refereed Journal Papers

1. 1. Secure Multi-party Matrix Invertibility Testing over Small Finite Fields. S. Han, J. Lee, S. Park and M. Son. IACR Communications in Cryptology, Vol. 3, No. 2, 2026.

   2. FRAST: TFHE-friendly Cipher Based on Random S-boxes. M. Cho, W. Chung, J. Ha, J. Lee, E. Oh and M. Son. IACR Transactions on Symmetric Cryptology, Vol. 2024, No. 3, pp.1-43, 2024.

   3. Security Analysis of the ISO standard OFB-DRBG. W. Chung, H. Kim, J. Lee and Y. Lee. Designs, Codes and Cryptography, Vol. 92, pp.3515-3532, 2024.

   4. ZLR: A Fast Online Authenticated Encryption Scheme Achieving Full Security. W. Choi, S. Hwang, B. Lee and J. Lee. Designs, Codes and Cryptography, Vol. 92, pp.3261-3316, 2024.

   5. Building PRFs from TPRPs: Beyond the Block and the Tweak Length Bounds. W. Choi, J. Lee and Y. Lee. IACR Transactions on Symmetric Cryptology, Vol. 2024, No. 1, pp.35-70, 2024.

   6. Partition and Mix: Generalizing the Swap-or-Not Shuffle. N. Jho and J. Lee. Designs, Codes and Cryptography, Vol. 91, pp.2237-2254, 2023.

   7. Alternative Tower Field Construction for Quantum Implementation of the AES S-box. D. Chung, S. Lee, D. Choi and J. Lee. IEEE Transactions on Computers, Vol. 71, issue 10, pp.2553-2564, 2022.

   8. CTET+: A Beyond-Birthday-Bound Secure Tweakable Enciphering Scheme Using a Single Pseudorandom Permutation. B. Cogliati, J. Ethan, V. Lallemand, B. Lee, J. Lee and M. Minier. IACR Transactions on Symmetric Cryptology, Vol. 2021, No. 4, pp.1-35, 2021.

   9. Forking Tweakable Even-Mansour Ciphers. H. Kim, Y. Lee, J. Lee. IACR Transactions on Symmetric Cryptology, Vol. 2020, No. 4, pp.71-87, 2020.

   10. Highly Secure Nonce-based MACs from the Sum of Tweakable Block Ciphers. W. Choi, A. Inoue, B. Lee, J. Lee, E. List, K. Minematsu and Y. Naito. IACR Transactions on Symmetric Cryptology, Vol. 2020, No. 4, pp.39-70, 2020.

   11. Masta: An HE-friendly Cipher Using Modular Arithmetic. J. Ha, S. Kim, W. Choi, J. Lee, D. Moon, H. Yoon and J. Cho. IEEE Access, Vol 8, pp.194741-194751, 2020.

   12. Minimizing the Two-Round Even-Mansour Cipher. S. Chen, R. Lampe, J. Lee, Y. Seurin and J. Steinberger. Journal of Cryptology, Vol. 31, No. 4, pp.1064-1119, 2018.

   13. Connecting tweakable and multi-key blockcipher security. J. Lee, A. Luykx, B. Mennink and K. Minematsu. Designs, Codes and Cryptography, Vol. 86, pp.623-640, 2018.

   14. Key alternating ciphers based on involutions. J. Lee. Designs, Codes and Cryptography, Vol. 86, pp.955-988, 2018.

   15. The Security of Tandem-DM in the Ideal Cipher Model. J. Lee, M. Stam and J. Steinberger. Journal of Cryptology, Vol. 30, No. 2, pp.495-518, 2017.

   16. Indifferentiability of the Sum of Random Permutations Towards Optimal Security. J. Lee. IEEE Transactions on Information Theory, Vol. 63, No. 6, pp.4050-4054, 2017.

   17. New Constructions of MACs from (Tweakable) Block Ciphers. B. Cogliati, J. Lee, Y. Seurin. IACR Transactions on Symmetric Cryptology, Vol. 2017, issue 2, pp.27-58, 2017.

   18. MJH: a faster alternative to MDC-2. J. Lee and M. Stam. Designs, Codes and Cryptography, Vol. 76, pp.179-205, 2015.

   19. Security of the Misty Structure Beyond the Birthday Bound. J. Lee. IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol. E97-A, No.7, pp.1516-1522, 2014.

   20. Security of permutation-based compression function lp231. J. Lee and D. Kwon. Information Processing Letters, Vol. 114, Issue 7, pp.372-381, 2014.

   21. Multi-property-preserving Domain Extension Using Polynomial-based Modes of Operation. J. Lee and J. Steinberger, IEEE Transactions on Information Theory, Vol. 58, No. 9 pp.6165-6182, 2012.

   22. Collision Resistance of the JH Hash Function. J.Lee and D.Hong, IEEE Transactions on Information Theory, Vol. 58, No. 3 pp.1992-1995, 2012.

   23. On Lai-Massey and quasi-Feistel ciphers. A. Yun, J. H. Park and J. Lee. Designs, Codes and Cryptography, Vol. 58, pp.45-72, 2011.

   24. The Security of Abreast-DM. J. Lee and D. Kwon. IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences Vol. E94-A, No.1, pp.104-109, 2011.

   25. Efficient and Secure Authenticated Key Exchange Protocols in the eCK model. J. Lee and J. H. Park. IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences Vol. E94-A, No.1, pp.129- 138, 2011.

   26. Security of the Misty Structure Using Involutions as Round Functions. J. Lee and B. Koo. IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol. E93-A, No.9, pp.1612-1619, 2010.

   27. Preimage Resistance of LPmkr with r=m-1. J. Lee and J. H. Park. Information Processing Letters, Vol. 110, Issues 14-15, pp.602-608, 2010.

   28. Impersonation Attack on the Strong Identification Based on a Hard-on-average Problem. B. Koo, J. Lee, D. Kwon and J. H. Song. Bulletin of the Korean Mathematical Society, Vol. 47, No. 1 pp.63-71, 2010.

   29. Tree-based Key Predistribution for Wireless Sensor Networks. J. Lee and D. Kwon. Wireless Networks, Vol. 15, Issue 8, pp.1140-1151, 2009.

   30. Efficient RFID Authentication Protocols Based on Pseudorandom Sequence Generators. J. Lee and Y. Yeom. Designs, Codes and Cryptography, Vol. 51, pp.195-210, 2009.

   31. On the Construction of Practical Key Predistribution Schemes for Distributed Sensor Networks Using Combinatorial Designs. J. Lee and D. R. Stinson. ACM Transactions on Information and System Security (TISSEC), Vol. 11, Issue 2, pp.1-35, 2008.

   32. Common Intersection Designs. J. Lee and D. R. Stinson. Journal of Combinatorial Designs, Vol. 14, Issue 4, pp.251-269, 2006.