Current public blockchains (e.g. Bitcoin and Ethereum) have been suffering from scalability issues since they were created. Compared with traditional payment systems such as Visa or Mastercard which can process thousands of transactions per second, Bitcoin and Ethereum can only achieve around ten transactions per second. This is due to the decentralized nature of public blockchains: every single move of each transaction will be executed and shared at every single node in the network. One naive approach to scaling blockchains is to increase the block size or reduce block production time. However, it will not only cause hard forks but also damage the security of the underlying blockchain. Thinking from a different perspective, do we really have to process every transactions on-chain? Can we move them off-chain? The answer is yes, and this talk will discuss what off-chain solutions are and how they scale public blockchains.

Fangyu Gai is a first-year Ph.D. student at School of Engineering, University of British Columbia (Okanagan Campus), supervised by Prof. Chen Feng, who is the co-cluster lead of Blockchain@UBC. His research interests lie in distributed system, cybersecurity, as well as blockchain technologies. Fangyu is currently focusing on off-chain scaling technologies, including payment channel networks and sidechains.