Academic Report of School of Mathematical Sciences [2025] No. 112

(Series Report for High-Level University Construction No. 1214)

Title: Isogeny-based Cryptosystems

Speaker: Professor Ouyang Yi (University of Science and Technology of China)

Time: 10:00-11:00, November 10, 2025 (Monday)

Location: Huiwen Building Room 2331

Abstract:

Isogeny-based cryptosystems represent a technical pathway in post-quantum cryptography. This report will introduce isogeny-based cryptography and the underlying mathematical hard problems it relies on. It will then present some of our research findings concerning the structure of supersingular elliptic curve isogeny graphs and the SQI signature scheme. This talk is based on collaborative work with Xu Zheng, among others.

Speaker Profile:

Ouyang Yi is a Professor and Ph.D. Supervisor in the Department of Mathematics at the University of Science and Technology of China (USTC). He received his B.Sc. (1993) and M.Sc. (1995) degrees from USTC, and his Ph.D. (2000) from the University of Minnesota, USA. From July 2000 to June 2003, he conducted postdoctoral research at the University of Toronto, Canada. He served as an Associate Professor at Tsinghua University from July 2003 and has been a Professor at USTC since December 2006. His primary research interests lie in algebraic number theory and arithmetic algebraic geometry, particularly p-adic Galois representation theory. He has presided over and completed several projects funded by the National Natural Science Foundation of China (NSFC) and leads a sub-project within a Quantum Pioneer Program. He is the chief editor of the algebra textbook series Algebra I-III, published by Higher Education Press. Professor Ouyang has received multiple teaching achievement awards from the Chinese Academy of Sciences and Anhui Province. His honors include the Second Prize of the Fok Ying Tung Education Foundation Higher Education Teaching Award (2022), the Baosteel Excellent Teacher Award (2017), Anhui Province Teaching Master (2018), the Outstanding Tutor Award (2020) and the Outstanding Management Personnel Award (2021) under the Ministry of Education's Program for Cultivating Top-notch Students in Basic Disciplines.

All faculty and students are welcome!

Host: Wang Yingnan

School of Mathematical Sciences

November 6, 2025