Candidate: Behkish Nassirzadeh
Date: September 26, 2024
Time: 12:30 PM
Location: Online - contact the candidate for more information.
Supervisor: Ganesh, Vijay – Hasan, Anwar
Abstract:
Over the past few years, we have witnessed a significant increase in the applications of Blockchain and smart contracts in various contexts. However, some limitations, such as security and connectivity, still prevent Blockchain from mass adaptation. Deployed smart contracts are immutable. Thus, unlike traditional software systems, they are vulnerable to latent security issues. Although many tools and techniques have been developed to detect various smart contract security vulnerabilities, the current solutions do not detect gas-related vulnerabilities reliably. Also, many of these solutions are yet to be implemented and tested in practice.
Moreover, smart contracts require mechanisms, often called oracles, to get access to off-chain data or another Blockchain. However, some significant problems with current Oracle technology are that they do not scale well, are plagued by trust issues, and only support limited applications. One application that the current Oracle solutions do not support reliably is counting systems. These systems count the occurrence of events, aiming to collect and analyze data that can be used in various applications such as voting, surveys, and digital ad impressions. To address the described problems, we first present a case study of Gas Gauge on a real-world application, Airswap, a peer-to-peer trading network for Ethereum. Gas Gauge is a tool that detects gas-based DoS vulnerabilities in Ethereum smart contracts. This case study shows how Gas Gauge can automatically and reliably detect gas-based DoS vulnerabilities to save millions of dollars and multiple man-hours. Then, we introduce CountChain, one of the first practical decentralized oracles for counting systems. We also present a case study of AdChain, a modification of CountChain that can solve discrepancy fraud in online advertising. This case study aims to show how a billion-dollar industry like online advertisement can adopt a Blockchain-based solution if the connectivity limitation of Blockchain is adequately addressed. Finally, a formal game theoretical analysis and experimental evaluation on the feasibility and security of CountChain, AdChain, and other decentralized oracle networks are provided. This is one of the first analyses of its kind, and it hopes to provide insightful information for future work in Blockchain connectivity.