Loi Luu

PhD Student

System Security Lab, School of Computing

National University of Singapore

AsianScientist (Apr. 19, 2017) – Bitcoins and blockchain may bring to mind images of hoodie-wearing hackers and programmers furiously typing away at keyboard. Bit for this month’s featured Rising Scientist Loi Luu, it is the face of his family, particularly his sister, that comes to mind.

Frustrated at the high cost and difficulty of transferring money from Singapore to his family in Vietnam, Loi immediately saw the potential of cryptocurrency as a way to securely transfer money without a middleman. Since then, he has dedicated his nascent research career to developing new technology for the blockchain, with the aim of making accessible for everyone.

In 2016, Loi was the recipient of the Microsoft Research Asia (MSRA) Fellowship, which supported him during a three-month stint at a top international research institute.

How would you summarize your research in a tweet (140 characters)? Analyzing the security of existing cryptocurrency systems, and proposing secure, scalable blockchain protocols for open networks.

Describe a completed research project that you are proudest of. Smart contracts are programs which securely executed distributedly by several participants in the network. In a paper accepted at a top tier computer security conference (Computer and Communications Security 2016), we introduced new security problems in existing Ethereum smart contracts, describing how an attacker can exploit smart contracts to manipulate the contract outcome, steal or sabotage funds of users. We proposed solutions to these attacks and a tool, namely Oyente, to detect if a smart contract is vulnerable. We run the tool with almost 20,000 existing smart contracts at the time we wrote the paper. Oyente has flagged almost 25 percent of them as vulnerable to at least one of the attacks, thus putting millions of dollars at risk. Our paper was well-received by the community and we have released Oyente open source. I’m happy to report that the tool is now integrated with the Ethereum project’s codebase. Another project which I am equally proud of is our work to address the scalability problem of existing blockchains. Popular blockchain agreement protocols exhibit security, but does not scale. We design a secure sharding protocol for open blockchains that scales transaction rates near linearly with the network size. In other words, the more nodes in the network, the higher the number of transaction blocks selected per unit time. We implemented our protocol and ran experiments on Amazon EC2 to verify that our solution can provide the theoretical scalability.

What do you hope to accomplish with your research in the next decade? We expect to solve other existing problems, e.g. privacy, usability, efficiency and so on, in cryptocurrency and blockchains. Our hope is to get our research results deployed in real systems as much as possible, thus directly benefiting millions of users.





Who (or what) motivated you to go into your field of study? When I first moved to Singapore, I face several problems of sending and receiving money from and to the country. For example, since I need to support my younger sister for her college, I had to send some of my scholarship stipend back to Vietnam quite often. It was really troublesome for me since the banks charged really high fees and offer a very low rate to transfer Singapore dollars to Vietnam. I often had to ask around for help, which took more time and bothered my friends. I came to know about Bitcoin in early 2014, and the more I learned about it, the more I was in awe. The idea of transacting money from anyone to anyone without relying on any centralized authority was just mind-blowing to me. It took me almost half a year to convince my advisor that the technologies behind Bitcoin are both technically and socially important, and very challenging at the same time. After that, I worked full-time on Bitcoin and blockchain research.

What is the biggest adversity that you experienced in your research? I sometimes struggle with a lack of collaborators on the same topic (which is my luck in some sense, since I don’t have many competitors; just joking!). It is mainly because blockchain and Bitcoin are new to the world (Bitcoin was first introduced in 2009 and launched in 2011). I often had to work alone (with significant help from my advisor) for a long time, and once we had been sure that we got something concrete, we invited new people to execute the project. Everyone knows the importance of having good collaborations, especially in research. Having to do everything from brainstorming, studying related literature, identifying the problems and solutions alone is painful and just overwhelming. Even if you have a solution for every problem, you yourself become the bottleneck of the project. Thus, I value good collaborators greatly.

What are the biggest challenges facing the academic research community today, and how can we fix them? I think it is the pressure of publishing papers and creating measurable results. It prevents young researchers from producing impactful results, prevents senior researchers from doing risky experiments which may turn out to be failures. To be honest I don’t know a good solution for it. I was, and still am, lucky to have a great supervisor who allows me to take risks, to experiment with my thoughts, who did not push me to work on something that I did not like, just to create some immediate results for existing projects. I wish other young researchers, e.g. PhD students like me, also find their great mentors/advisors who can support them to purchase their very own research interests.

If you had not become a scientist, what would you have become instead? I would be a software developer working on my own startup. I like solving interesting problems, and a startup seems to be a good place to find challenging problems.

Outside of work, what do you do to relax? Playing sport and reading books. I love playing football, I play every weekend with other students from NUS (friendly matches only).







If you had the power and resources to eradicate any world problem using your research, which one would you solve? I would like to deploy cryptocurrency and blockchain technology worldwide to eliminate the concept of national currencies, remove centralized banks and renovate existing financial systems. Blockchains have been shown to improve the financial inclusions, allow cheap and efficient cross-border transactions, and enable more useful applications which are not feasible in existing systems.