00000nam 2200000zi 4500 9.944004 CaOODSP 20251202083747 m o d f cr mn||||||||| 241010t20242024onca ob f000 0 eng d CaOODSP eng rda CaOODSP eng eng fre FB3-6/2024-10E-PDF Deng, Xun, author. Analysis of DeFi oracles / by Xun Deng, Sidi Mohamed Beillahi, Cyrus Minwalla, Han Du, Andreas Veneris and Fan Long. [Ottawa] : Bank of Canada = Banque du Canada, 2024. ©2024 1 online resource (ii, 21 pages) : illustrations (some colour). text txt rdacontent computer c rdamedia online resource cr rdacarrier Staff discussion paper = Document d'analyse du personnel, 1914-0568 ; 2024-10 ISSN assigned to different series. "Last updated: July 9, 2024." Includes bibliographical references (pages 17-21). "This paper presents OVer, a framework designed to automatically analyze the behaviour of decentralized finance (DeFi) protocols when subjected to a "skewed" oracle input. OVer firstly performs a symbolic analysis on the given contract and constructs a model of constraints. Then, the framework leverages a satisfiability modulo theory solver to identify parameters that allow its secure operation. Furthermore, guard statements can be generated for smart contracts that may use the oracle values, thus effectively preventing oracle manipulation attacks. Empirical results show that OVer can successfully analyze all 10 benchmarks collected, which encompass a diverse range of DeFi protocols. Additionally, this paper illustrates that current parameters used in the majority of benchmarks are inadequate to ensure safety when confronted with significant oracle deviations. It shows that existing ad-hoc control mechanisms such as introducing delays are often insufficient or even detrimental to protect the DeFi protocols against the oracle deviation in the real world. Moreover, this paper delves into the design considerations of price oracles within a potential blockchain-based digital currency"--Abstract, page ii. Includes abstracts in English and French. Financial services industry Data processing. Smart contracts. Blockchains (Databases) Services financiers Informatique. Contrats intelligents. Chaînes de blocs. Bank of Canada, issuing body. Staff discussion paper (Bank of Canada) 2024-10. (CaOODSP)9.806273 PDF 1.38 MB https://publications.gc.ca/collections/collection_2024/banque-bank-canada/FB3-6-2024-10-eng.pdf