Shi, Weidong2022-06-17December 22021-12December 2Portions of this document appear in: Kaleem, Mudabbir, Keshav Kasichainula, Rabimba Karanjai, Lei Xu, Zhimin Gao, Lin Chen, and Weidong Shi. "An event driven framework for smart contract execution." In Proceedings of the 15th ACM International Conference on Distributed and Event-based Systems, pp. 78-89. 2021; and in: Kaleem, Mudabbir, and Weidong Shi. "Demystifying pythia: A survey of chainlink oracles usage on ethereum." In International Conference on Financial Cryptography and Data Security, pp. 115-123. Springer, Berlin, Heidelberg, 2021.https://hdl.handle.net/10657/9279The thesis is composed of two essays related to smart contract systems on public permission-less blockchains. Firstly, the thesis presents EDSC, a novel smart contract platform design based on the event-driven execution model as opposed to the traditionally employed transaction-driven execution model. It reasons that such a design is a better fit for many emerging smart contract applications and is better positioned to address the scalability and performance challenges plaguing the smart contract ecosystem. It proposes EDSC’s design under the Ethereum framework, and the design can be easily adapted for other existing smart contract platforms. Secondly, the thesis presents a study of oracle usage on Ethereum, the most popular permission-less smart contract platform. It performs an empirical study of oracle systems’ usage trends and adoption metrics to provide better insight into the health of the smart contract ecosystem.application/pdfengThe author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. UH Libraries has secured permission to reproduce any and all previously published materials contained in the work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s).Blockchain, Smart Contracts, Ethereum, Event-driven, Oracles2022-06-17Thesisborn digital