Secure Smart Contract-based Computation (Verifiable computation, Fair two-party protocols, and Resource sharing)

Avizheh, Sepideh

Secure Smart Contract-based Computation (Verifiable computation, Fair two-party protocols, and Resource sharing)

dc.contributor.advisor	Safavi-Naini, Reihaneh
dc.contributor.author	Avizheh, Sepideh
dc.contributor.committeemember	Jacobson Jr., Michael John
dc.contributor.committeemember	Henry, Ryan
dc.contributor.committeemember	Far, Behrouz
dc.contributor.committeemember	Pieprzyk, Josef
dc.date	2024-05
dc.date.accessioned	2024-02-20T14:42:56Z
dc.date.available	2024-02-20T14:42:56Z
dc.date.issued	2024-02-15
dc.description.abstract	A smart contract is a trusted computer program that runs on the decentralized computer that underlies a blockchain. Smart contracts are part of Web3 technology, the next generation of the Internet, and they enable distributed applications over the Internet. Smart contracts can remove intermediaries in real-world systems and have the promise of revolutionizing industries and processes in healthcare, retail, banking, government, and many more. Because of their trusted execution, smart contracts have been used as a trusted third party/referee in cryptographic protocols. They have also been used to automate processes and seamlessly incorporate cryptocurrency in payments. In this thesis, we consider the application of the smart contract as a trusted (semi-honest) third party/referee in the following problems: verifiable computation using refereed delegation of computation, fair two-party protocols that include fair private set intersection and fair exchange, and resource sharing. We show that the direct replacement of the trusted third party/referee with the smart contract can expose the protocols to new threats and attacks. We model the security of each protocol, analyze the security of the existing ones, propose new protocols that can achieve the required security guarantee in the smart contract setting, provide a proof-of-concept implementation, and evaluate their performance. Our results incorporate both secure smart contract-based cryptographic protocols and systems. We mainly propose formal models and descriptions in the real-world/ideal-world paradigm for the cryptographic protocols. We also look into the privacy in the smart contract setting. The smart contract is transparent and interactions with the smart contract are through public communication channels, thus ensuring the privacy of the parties' input and messages becomes a significant challenge in designing the protocols. We lay the foundations to define and capture privacy for a smart contract and use it to show the privacy of our cryptographic protocols.
dc.identifier.citation	Avizheh, S. (2024). Secure smart contract-based computation (verifiable computation, fair two-party protocols, and resource sharing) (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.uri	https://hdl.handle.net/1880/118193
dc.language.iso	en
dc.publisher.faculty	Graduate Studies
dc.publisher.institution	University of Calgary
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject	Information security
dc.subject	Cryptography
dc.subject	Blockchain and smart contracts
dc.subject	Verifiable computation
dc.subject	Fair two-party protocols
dc.subject	Resource sharing
dc.subject	Distributed systems security
dc.subject.classification	Computer Science
dc.title	Secure Smart Contract-based Computation (Verifiable computation, Fair two-party protocols, and Resource sharing)
dc.type	doctoral thesis
thesis.degree.discipline	Computer Science
thesis.degree.grantor	University of Calgary
thesis.degree.name	Doctor of Philosophy (PhD)
ucalgary.thesis.accesssetbystudent	I do not require a thesis withhold – my thesis will have open access and can be viewed and downloaded publicly as soon as possible.