报告题目：Towards More efficient Decentralised Anonymous Payment Systems based on Arguments for Arithmetic Circuit Satisfiability

报告人：Man Ho Au 教授, 香港理工大学

报告时间：19:30-21:00, 2018年7月5号

报告地点：长安校区 文津楼三段622报告厅

主办单位：信息安全科研团队

报告摘要:

Digital currencies like Bitcoin and other blockchain based systems provide means to record monetary transfers between accounts. In Bitcoin-like systems transactions are published on a decentralized ledger and reveal the sender, receiver and amount of a transfer, hence such systems give only moderate anonymity guarantees.

Several cryptocurrencies aim to improve anonymity guarantees by hiding the origin, destination and value of a payment. One of the most famous examples, ZCash, leverages Zero-Knowledge Succinct Non-Interactive Arguments of Knowledge (zk-SNARK) of arithmetic circuit satisfiability to achieve the purpose. One drawback of ZCash is that the arithmetic circuit is rather large, thus requires a large common reference string and complex prover for the ZK-SNARK. In fact, the memory and prover complexity are dominated by the zk-SNARK in use and is mainly determined by the complexity of the circuit.

In this talk, we discuss zk-SNARK for arithmetic circuit. Then, we present our recent results in improving efficiency of decentralised anonymous payment systems. In particular, we explore the use of algebraic primitives in which satisfiability might be efficiently verified by an arithmetic circuit. We also introduce some of our recent blockchain projects.

报告人介绍：

 Dr. Man Ho Au received his PhD degree from the University of Wollongong in 2009. He is now an assistant professor and a director of the Monash-PolyU-CC Joint Lab on Blockchain and Cryptocurrency at Department of Computing, the Hong Kong Polytechnic University. His research interests include information security and blockchain technology. He has published over 130 refereed papers in top journal and conferences, including ACM CCS, ACM SIGMOD, NDSS, IEEE TIFS, TC, TKDE, etc. He is a recipient of the 2009 PET runner-up award for outstanding research in privacy enhancing technologies. He received best paper awards from conferences including ACISP 2016 and ISPEC 2017. According to Google Scholar, his h-index is 33 and his work has been cited over 3200 times. He is an expert member of the China delegation of ISO/IEC JTC 1/SC 27 working group 2 - Cryptography and security mechanisms. He is also a committee member of the Hong Kong Blockchain Society R&D division.