His citations in scholar.google is 11,000+ with h-index 46. He is one of the co-inventors of braid cryptography and (independently) Xedni calculus on elliptic curve discrete logarithms. His works on improved Pollard rho algorithm and an efficient algorithm on strong DH problem drew much attention, the former of which won the best paper award in Asiacrypt 2008. He received the best paper award in Eurocrypt 2015 for this joint work on cryptanalysis of multilinear maps. As one of co-inventors of approximate homomorphic encryption HEaaN, he is actively working on homomorphic encryptions and their applications such as machine learning on encrypted data and Private AI.

He is an associate editor of “Design, Codes and Cryptography”,“Journal of Communica- tion Network” and “Journal of Cryptology” that is the fagship journal of International Association of Cryptologic Research (IACR). He co-chaired ANTS-XI, Asiacrypt 2015/2016, MathCrypt 2018/2019/2021, and PQCrypto 2021/2022 and served as program committee for major crypto conferences. He was selected as Scientist of the month by Korean government in 2018 and won the POSCO science prize in 2019 and the PKC Test-of-Time award in 2021. He received Korean Order of Service Merit (Green Stripes, 2022) and is a member of the Korean Academy of Science and Technology. He is appointed as a fellow of IACR in 2023.