报告题目【Generic Construction of Ring Signatures with Efficient Instantiations】
时间：2021年6月9日 (星期三) 下午15:00 —17:00
参加对象：感兴趣的师生（腾讯会议 ID：614 697 016）
报告摘要：We introduce a novel generic ring signature construction, called DualRing, which can be built from several canonical identification schemes (such as Schnorr identification). DualRing differs from the classical ring signatures by its formation of two rings: a ring of commitments and a ring of challenges. It has a structural difference from the common ring signature approaches based on accumulators or zero-knowledge proofs of the signer index. Comparatively, DualRing has a number of unique advantages.
Considering the DL-based setting by using Schnorr identification scheme, our DualRing structure allows the signature size to be compressed into logarithmic size via an argument of knowledge system such as Bulletproofs. We further improve on the Bulletproofs argument system to eliminate about half of the computation while maintaining the same proof size. We call this Sum Argument and it can be of independent interest. This DL-based construction, named DualRing-EC, using Schnorr identification with Sum Argument has the shortest ring signature size in the literature without using trusted setup.
Considering the lattice-based setting, we instantiate DualRing by a canonical identification based on M-LWE and M-SIS. In practice, we achieve the shortest lattice-based ring signature, named DualRing-LB, when the ring size is between 4 and 2000. DualRing-LB is also 5x faster in signing and verification than the fastest lattice-based scheme by Esgin et al. (CRYPTO'19).(This presentation is based on the paper accepted in CRYPTO 2021.)
报告人简介：Joseph Liu is an Associate Professor in the Faculty of Information Technology, Monash University in Melbourne, Australia. He got his PhD from the Chinese University of Hong Kong at 2004. His research areas include cyber security, blockchain and applied cryptography. He has received more than 9000 citations and his H-index is 54, with more than 200 publications in top venues such as CRYPTO, ACM CCS, NDSS, INFOCOM. He is currently the lead of the Monash Cyber Security Discipline Group. He has established the Monash Blockchain Technology Centre at 2019 and serves as the founding director. His remarkable research in linkable ring signature forms the theory basis of Monero (XMR), one of the largest cryptocurrencies in the world with current market capitalization more than US$6 billion. He has been given the prestigious ICT Researcher of the Year 2018 Award by the Australian Computer Society (ACS), the largest professional body in Australia representing the ICT sector, for his contribution to the blockchain and cyber security community. He has been invited as the IEEE Distinguished Lecturer in 2021 for the topic of Blockchain in Supply Chain.