学术报告：Post-Quantum Cryptocurrency: Ring Confidential Transactions Protocols in Lattice Settings
时间：2022年6月8日星期三晚上7:00pm-8:00pm（北京时间）
地点：腾讯会议（323-726-554）
报告人：GAO Shang，香港理工大学，研究助理教授
题目：Post-Quantum Cryptocurrency: Ring Confidential Transactions Protocols in Lattice Settings
内容简介：The development of quantum computers raises security concerns due to their ability to efficiently solve classical problems such as discrete logarithm and integer factorization problems. These concerns also urge the development of post-quantum techniques in blockchain-based anonymous cryptocurrencies. In this talk, we propose new zero-knowledge proofs for practical post-quantum ring confidential transaction (RingCT) protocols based on lattice assumptions for anonymous cryptocurrencies. First, we introduce an inner-product based linear equation satisfiability approach for balance proofs with a wide range (e.g., 64-bit precision). Unlike existing balance proofs that require additional proofs for some corrector values [CCS'19], our approach avoids the corrector values for better efficiency. Furthermore, we design a ring signature scheme to hide a user's identity in large anonymity sets efficiently. Different from existing approaches that adopt a one-out-of-many proof [CCS'19, Crypto'19], we show that a linear sum proof suffices in ring signatures which could avoid the costly binary proof part. We further use the idea of unbalanced relations to build a logarithmic-size ring signature scheme. Finally, we show how to adopt these techniques in RingCT protocols and implement a prototype to compare the performance with existing approaches. We also believe our techniques are of independent interest for other privacy-preserving applications such as secure e-voting and are applicable in a generic setting.
个人简介：Dr. Shang is the research assistant professor in the Department of Computing in the Hong Kong Polytechnic University. He obtained his Ph.D. degree from the Hong Kong Polytechnic University in 2019, supervised by Dr. Bin XIAO. He received his M.Eng. degree from Southeast University, China and B.Ss. degree from Hangzhou Dianzi University, China, in 2014 and 2010 respectively. After graduation, he worked in Microsoft China for one year. Dr Gao is broadly interested in different security-related areas. Currently, he focuses on blockchain security and applied cryptography. His work has been published in several top-tier conferences and journals, including CCS, INFOCOM, TDSC, TON, etc.
中文简介：高尚博士是香港理工大学计算机系的研究助理教授。他于2019年在香港理工大学获得博士学位，导师为肖斌博士。他分别于2014年和2010年获得中国东南大学的工程硕士学位和中国杭州电子科技大学的学士学位。毕业后，他在微软中国工作了一年。高博士对不同的安全相关领域有广泛的兴趣。目前，他专注于区块链安全和应用密码学。他的工作已经发表在多个顶级会议和期刊上，包括CCS、INFOCOM、TDSC、TON等。
宣讲人：Bin Xiao, 香港理工大学, 教授
个人简介：Dr. Bin Xiao is a full professor in the Department of Computing, the Hong Kong Polytechnic University. He has been the dept. research committee chair (DRC Chair, 2018 - 2021). He received the B.Sc and M.Sc degrees in the Electronics Engineering from Fudan University, China, and Ph.D. degree in Computer Science from University of Texas at Dallas, USA. After his Ph.D. graduation, he joined the Hong Kong Polytechnic University as an assistant professor. Currently, he is the associate editor of IEEE TCC, IEEE TNSE, IEEE IoTJ, Elsevier JPDC, the vice chair of IEEE ComSoc Communications and Information Security Technical Committee (CISTC), a senior member of the IEEE and a member of the ACM.
中文简介：肖斌教授是香港理工大学计算机系的全职教授。他一直是系里的研究委员会主席（DRC Chair, 2018 - 2021）。他在中国复旦大学获得电子工程学士和硕士学位，并在美国德州大学达拉斯分校获得计算机科学博士学位。博士毕业后，他加入香港理工大学，担任助理教授。目前，他是IEEE TCC、IEEE TNSE、IEEE IoTJ、Elsevier JPDC的副编辑，IEEE ComSoc通信和信息安全技术委员会（CISTC）的副主席，IEEE高级会员和ACM会员。
博士招生：In general, we are looking for good Ph.D. candidates all year around (fellowship HK$18,100 per month) in the areas of AI and network security, Data Privacy, and Blockchain Systems.
