This talk has two parts. The first part provides an overview of some of the key security and privacy challenges in blockchain that we have been working on. In the second part, I will talk about our recent work (CSF’19) on how to understand and analyse transaction untraceability from a different perspective. In this work, we develop new foundations on transaction untraceability for CryptoNote-style blockchain systems. In particular, we observe new attacks; develop theoretical foundations to model transaction untraceability; provide the least upper bound of transaction untraceability guarantee; provide ways to efficiently and automatically verify whether a given ledger achieves optimal transaction untraceability, and provide a general solution that achieves provably optimal transaction untraceability.
Jiangshan Yu is a lecturer at Monash University, Australia, and an honorary research fellow at University of Birmingham, UK, where he received his PhD degree. Concerning the blockchain research field, his research challenges the soundness of the foundational security models and design principles of existing blockchain systems, where the blockchain ecosystem of over 254 Billion US dollars is based upon. His research provides breakthroughs on the underlying blockchain system design. For example, his research on blockchain consensus, named RepuCoin (IEEE Trans. on Computers’ 19), provides a world-first blockchain system that is able to tolerate 51% attacks. His work (CSF’19, FC’ 19, ASIACCS’19) on analysing the security of real-world blockchains has exposed several critical vulnerabilities in the leading blockchains (with a total market cap of billions of US dollars). All vulnerabilities are disclosed to the associated teams and have been patched where possible. His work on ledger-based end-to-end secure messaging system, called DECIM (IEEE TIFS’18), provides the first end-to-end secure messaging system that is able to detect the compromise of secret keys. This is recognised as a breakthrough in messaging privacy by using a public ledger.
He has obtained several awards to recognise his research outcomes. He received the Dean’s Research Impact Award at Monash University (2019); had been a finalist for Endeavour Awards which is a part of the Premier Awards Program in Australia (2019); received Chinese Government Award for Outstanding PhD Scholar Abroad (success rate: 1% worldwide, 2016); and had been a finalist for RAEng Enterprise Fellowship from the Royal Academy of Engineering (RAEng), UK (2015). His works have also achieved global coverage in hundreds of news media including ZDNet, Finder, Toutiao, Sohu, BTC Wires, ScienceDaily, Ethereum World News, EurekAlert!, The US Breaking news, Homeland Security Today, etc.