Practical Post-Quantum Zero-Knowledge Proofs and Private Cryptocurrencies

Dr. Ron Steinfeld

Monash University 

We discuss new techniques for design and analysis of efficient lattice-based zero-knowledge proofs (ZKP). First, we review previous work, and then introduce our recent work on one-shot proof techniques for non-linear polynomial relations, where the protocol achieves a negligible soundness error in a single execution, and thus performs significantly better in both computation and communication compared to prior protocols requiring multiple repetitions. To illustrate the utility of our techniques, we explain how to use them to build efficient relaxed proofs for important relations, such as one-out-of-many proofs. Despite their relaxed nature, we further show how our proof systems can be used as building blocks for advanced cryptographic tools such as ring signatures. Our ring signature achieves a dramatic improvement in length over all the previous proposals from lattices at the same security level. We then discuss an extension of our techniques to construct a practical lattice-based privacy-preserving blockchain cryptocurrency protocol called MatRiCT.


Ron Steinfeld received his Ph.D. degree in Computer Science in 2003 from Monash University, Australia. Since 2015, he is a Senior Lecturer at the Faculty of Information Technology, Monash University, Australia. Following his Ph.D. Ron worked as a postdoctoral research fellow in cryptography and information security at Macquarie University, Australia, holding the positions of Macquarie University Research Fellow in cryptography and information security (2007-2009), and ARC Australian Research Fellow in cryptography and information security (2009- 2012). Ron completed his ARC Research Fellowship at Monash University (2012-2014). His main research interests are in the design and analysis of cryptographic algorithms and protocols, in particular in the areas of post-quantum cryptography and secure computation protocols. He has over 18 years of research experience in cryptography and information security. He has published more than 60 research papers in international refereed conferences and journals, more than 10 of which have each been cited over 100 times. He received the ASIACRYPT 2015 best paper award. He has served on the technical Program Committee of numerous international conferences in cryptography, is an editorial board member of the journal `Designs Codes and Cryptography’, and consults in cryptography design for the software industry.