Blockchain Oracles: State-of-the-Art and Research Directions

Blockchain interoperability is an innovative feature of blockchain technology that is rapidly gaining momentum in various fields. The mass adoption of enterprise blockchains has not yet been achieved because blockchain networks act as isolated islands that cannot connect or exchange assets and/or in...

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Main Authors: Shahinaz Kamal Ezzat, Yasmine N. M. Saleh, Ayman A. Abdel-Hamid
Format: Article
Language:English
Published: IEEE 2022-01-01
Series:IEEE Access
Subjects:
Online Access:https://ieeexplore.ieee.org/document/9801856/
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author Shahinaz Kamal Ezzat
Yasmine N. M. Saleh
Ayman A. Abdel-Hamid
author_facet Shahinaz Kamal Ezzat
Yasmine N. M. Saleh
Ayman A. Abdel-Hamid
author_sort Shahinaz Kamal Ezzat
collection DOAJ
description Blockchain interoperability is an innovative feature of blockchain technology that is rapidly gaining momentum in various fields. The mass adoption of enterprise blockchains has not yet been achieved because blockchain networks act as isolated islands that cannot connect or exchange assets and/or information. In addition, the invocation of smart contracts is restricted only to on-chain executions because of the lack of connectivity between the blockchains. This paper aims to conduct a comprehensive and thorough literature review regarding blockchain interoperability, with special highlight on blockchain Oracles being state-of-the-art. Oracles have shown potential as an emerging technology that has revolutionized the blockchain ecosystem by acting as agents that fetch external information into the blockchain ecosystem. A detailed comparative discussion of different blockchain interoperability techniques is presented, showing the strengths and weaknesses of each technique. Being overlooked in the literature, the shortcomings of these techniques in comparison to Oracles are identified, addressing how Oracles have succeeded in overcoming many of these limitations. In addition, the literature lacks a focus on the latest market solutions adopting blockchain Oracles, and only a few studies have considered them in detail. This gap has been addressed through an in-depth assessment of the latest market solutions adopting Oracles in the past few years. Finally, design issues trying to achieve the best practices of Oracles, future directions, and identified research gaps are highlighted.
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spelling doaj.art-599f2d938c2e4b7198ffdb9ff26d3bed2022-12-22T03:32:19ZengIEEEIEEE Access2169-35362022-01-0110675516757210.1109/ACCESS.2022.31847269801856Blockchain Oracles: State-of-the-Art and Research DirectionsShahinaz Kamal Ezzat0https://orcid.org/0000-0003-2669-9975Yasmine N. M. Saleh1https://orcid.org/0000-0002-2147-8017Ayman A. Abdel-Hamid2https://orcid.org/0000-0001-9953-7147College of Computing and Information Technology, Arab Academy for Science, Technology and Maritime Transport, Alexandria, Abukir, EgyptCollege of Computing and Information Technology, Arab Academy for Science, Technology and Maritime Transport, Alexandria, Abukir, EgyptCollege of Computing and Information Technology, Arab Academy for Science, Technology and Maritime Transport, Alexandria, Abukir, EgyptBlockchain interoperability is an innovative feature of blockchain technology that is rapidly gaining momentum in various fields. The mass adoption of enterprise blockchains has not yet been achieved because blockchain networks act as isolated islands that cannot connect or exchange assets and/or information. In addition, the invocation of smart contracts is restricted only to on-chain executions because of the lack of connectivity between the blockchains. This paper aims to conduct a comprehensive and thorough literature review regarding blockchain interoperability, with special highlight on blockchain Oracles being state-of-the-art. Oracles have shown potential as an emerging technology that has revolutionized the blockchain ecosystem by acting as agents that fetch external information into the blockchain ecosystem. A detailed comparative discussion of different blockchain interoperability techniques is presented, showing the strengths and weaknesses of each technique. Being overlooked in the literature, the shortcomings of these techniques in comparison to Oracles are identified, addressing how Oracles have succeeded in overcoming many of these limitations. In addition, the literature lacks a focus on the latest market solutions adopting blockchain Oracles, and only a few studies have considered them in detail. This gap has been addressed through an in-depth assessment of the latest market solutions adopting Oracles in the past few years. Finally, design issues trying to achieve the best practices of Oracles, future directions, and identified research gaps are highlighted.https://ieeexplore.ieee.org/document/9801856/Blockchaininter-blockchaininteroperabilityOraclessmart contracts
spellingShingle Shahinaz Kamal Ezzat
Yasmine N. M. Saleh
Ayman A. Abdel-Hamid
Blockchain Oracles: State-of-the-Art and Research Directions
IEEE Access
Blockchain
inter-blockchain
interoperability
Oracles
smart contracts
title Blockchain Oracles: State-of-the-Art and Research Directions
title_full Blockchain Oracles: State-of-the-Art and Research Directions
title_fullStr Blockchain Oracles: State-of-the-Art and Research Directions
title_full_unstemmed Blockchain Oracles: State-of-the-Art and Research Directions
title_short Blockchain Oracles: State-of-the-Art and Research Directions
title_sort blockchain oracles state of the art and research directions
topic Blockchain
inter-blockchain
interoperability
Oracles
smart contracts
url https://ieeexplore.ieee.org/document/9801856/
work_keys_str_mv AT shahinazkamalezzat blockchainoraclesstateoftheartandresearchdirections
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AT aymanaabdelhamid blockchainoraclesstateoftheartandresearchdirections