Layer-2 Solutions for Bitcoin Scalability

Bitcoin can only process around 7 transactions per second on average which is much lower than the figures for centralised payment systems such as Visa. Payment channel is an effective approach to improve the scalability of blockchain-based cryptocurrencies. However, none of the current payment channel schemes achieve all the required properties. This thesis formally defines the required properties of a payment channel, examines the existing schemes with respect to the defined properties and finally proposes new schemes that outperform the current ones.