Blockchain System Designs from the End-to-End Principle

Abstract

Blockchain is a system of computers and user endpoints owned by decentralized entities across the world and connected by an open Internet. It enables uncoordinated parties to interact with a shared state, but at every moment maintains a common view about the state among everyone without a centralized trusted entity. Those features have made Blockchain a unique digital platform for shared state applications, because it is open to all application developers and any users canpermissionlessly interact with it. Under the hood, a blockchain is made of layers of distributed protocols to endure adversarial participants and network environment. As workload and interactions among protocols increase, it is necessary to decouple functionalities through abstraction, such that independent development on separate protocols is possible while maintaining interoperability to the rest of the system. But naive abstraction can introduce unnecessary complexity, especially when lower layers contain unwanted and redundant features. The end to end design principle provides a guideline to delineate boundary between layers for reducing those adverse effects. This thesis contains four innovations for blockchains at the layers of Network, Data Availability, Censorship Resistance and Fair Ordering. While taking consideration from the end-to-end principle, those protocols improve the performance of the existing protocols and expand additional functionalities. Combining them altogether creates a blockchain that offers both superior performance and maximal flexibility for applications.