报告摘要：Public key cryptosystems  (PKC) are critical part of the  foundation of modern communication systems, in particular, Internet. However Shor's algorithm shows that the existing PKC like Diffie-Hellmann key exchange, RSA and ECC can be broken by a quantum computer. To prepare for the coming age of quantum computing, we need to build new public key cryptosystems that could resist quantum computer attacks.  In this lecture, we will give a brief introduction to post-quantum cryptography. Then we will present a practical and provably secure  (authenticated) key exchange protocol based on  the learning with errors problems, which is conceptually simple and has strong provable security properties.  This new constructions was established in 2011-2012.  We will explain that all the existing LWE based key exchanges are variants of this fundamental design.  In addition,  we will explain  how to use the signal function invented for KE for authentication schemes. Then we will discuss key-reuse attacks on those key exchanges.

个人简介：Jintai Ding is a professor at the Yau Mathematical Sciences Center at Tsinghua University and the director of Ding Lab in Privacy Protection and Blockchain Security at Beijing Institute of Mathematical Sciences and Applications. Before that he was a Charles Phelps Taft professor at the Department of Mathematical Sciences at the University of Cincinnati. He received B.A. from Xian Jiao tong University in 1988, M.A. from the University of Science and  technology of China in 1990 and Ph.D from Yale in 1995. He was a lecturer at the Research Institute of Mathematical Sciences of Kyoto University from 1995 to 1998. In 2006-2007, he was a visiting professor and Alexander Von Humboldt Fellow at TU Darmstadt. He received the Zhong Jia Qing Prize from the Chinese Mathematical Society in 1990 for his Master Thesis. His research was originally in quantum affine algebras and its representation theory, where he was credited for the invention of the Ding-Iohara-Miki algebra.  His current interest is in post-quantum cryptography, in particular, multivariate cryptography,  latticed-based cryptography and quantum-proof blockchain. He was a co-chair of the 2^nd ,10^th and 11^th international conference on post-quantum cryptography. He and his colleagues developed the Rainbow signature and the LWE-based key exchange schemes. Rainbow is a third round finalist candidate for the NIST post-quantum standardization process. He and his colleagues completely broke a NIST second round post-quantum signature candidate LUOV and a third round candidate GeMSS (HFEv-), which won honorable mention for best paper award for Crypto 2021.