Smart Contract Data Feed Framework for Privacy-Preserving Oracle System on Blockchain

Park, Junhoo; Kim, Hyekjin; Kim, Geunyoung; Ryou, Jae-Cheol

doi:10.3390/computers10010007

Cited by 24 publications

(19 citation statements)

References 16 publications

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“…What a centralized oracle does is it creates a direct channel between the data source and the smart contract. Oraclize, for example, is a trusted centralized oracle provider [26] whose objective is to prove that the fetched data have not been altered after being gathered [19]. In their official documents, they specify that they are not trustless but "provably" honest.…”

Section: Literature Backgroundmentioning

confidence: 99%

The Blockchain Oracle Problem in Decentralized Finance—A Multivocal Approach

Caldarelli

Ellul

2021

Applied Sciences

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Decentralized Finance (DeFi) takes the promise of blockchain a step further and aims to transform traditional financial products into trustless and transparent protocols that run without involving intermediaries. Similar to how 2017 was the year of ICOs, 2020 was the year of DeFi, with more than fifteen billion dollars of total investments. The decentralized platforms utilize oracles to retrieve asset data from the external world, but their choice and management criteria are often unknown to the end-users. If oracles are poorly selected or managed, the funds of a rising number of investors are inevitably in danger. The issue, known as “the oracle problem”, which makes real-world applications controversial and debated due to the loss of decentralization, had recently drawn attention to DeFi, given the crescent number of related hacks that caused the loss of millions of dollars held in DeFi projects. Through a multivocal approach that considers academic papers, whitepapers, preprints, and opinion posts, this study aims to shed light on the pattern that identifies the oracle problem in DeFi and outline the most promising ways to overcome the related weaknesses. This research supports the view that the oracle problem in decentralized finance bears specific characteristics which require standardization and appropriate economic incentives to be addressed.

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Section: Literature Backgroundmentioning

confidence: 99%

The Blockchain Oracle Problem in Decentralized Finance—A Multivocal Approach

Caldarelli

Ellul

2021

Applied Sciences

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“…What a centralized oracle does is it creates a direct channel between the data source and the smart contract. Oraclize for example is a trusted centralized oracle provider [47] whose objective is to prove that the fetched data has not been altered after being gathered [31]. In their official documents, they specify that they are not trustless but "provably" honest.…”

Section: Oracles Explainedmentioning

confidence: 99%

The Blockchain Oracle Problem in Decentralized Finance - A Multivocal Approach

Caldarelli¹,

Ellul²

2021

Preprint

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Decentralized Finance (DeFi) takes the promise of blockchain a step further and aims to transform traditional financial products into trustless and transparent protocols that run without involving intermediaries. Similar to how 2017 was the year of ICOs, 2020 was the year of DeFI with more than $15 billion of total investments. The decentralized platforms utilize oracles to retrieve asset data from the external world, but their choice and management criteria are often unknown to the end-users. If oracles are poorly selected or managed, the funds of a rising number of investors are inevitably in danger. The issue known as “the oracle problem,” which makes real-world applications controversial and debated due to the loss of decentralization, had recently drawn attention to DeFi given the crescent number of related hacks that caused the loss of millions of dollars held in DeFi projects. With a multivocal approach, this paper aims to shed light on the pattern that identifies the oracle problem in DeFi and outline the most promising ways to overcome the related weaknesses. This research supports the view that the oracle problem in decentralized finance bears specific characteristics which require standardization and appropriate economic incentives to be addressed.

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“…In other words, it manages data by storing large amounts of data in external storage, and storing the reference values of the data, access authority information, and key values in the blockchain. There are existing studies [10,28] that combine on-chain and off-chain scaling; however, there is an oracle problem when importing external data into the blockchain [29].…”

Section: Blockchain-based Large Data Managementmentioning

confidence: 99%

Two-Level Blockchain System for Digital Crime Evidence Management

Kim

Ihm

Son

2021

Sensors

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Digital evidence, such as evidence from CCTV and event data recorders, is highly valuable in criminal investigations, and is used as definitive evidence in trials. However, there are risks when digital evidence obtained during the investigation of a case is managed through a physical hard disk drive until it is submitted to the court. Previous studies have focused on the integrated management of digital evidence in a centralized system, but if a centralized system server is attacked, major operations and investigation information may be leaked. Therefore, there is a need to reliably manage digital evidence and investigation information using blockchain technology in a distributed system environment. However, when large amounts of data—such as evidence videos—are stored in a blockchain, the data that must be processed only within one block before being created increase, causing performance degradation. Therefore, we propose a two-level blockchain system that separates digital evidence into hot and cold blockchains. In the criminal investigation process, information that frequently changes is stored in the hot blockchain, and unchanging data such as videos are stored in the cold blockchain. To evaluate the system, we measured the storage and inquiry processing performance of digital crime evidence videos according to the different capacities in the two-level blockchain system.

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Smart Contract Data Feed Framework for Privacy-Preserving Oracle System on Blockchain

Cited by 24 publications

References 16 publications

The Blockchain Oracle Problem in Decentralized Finance—A Multivocal Approach

The Blockchain Oracle Problem in Decentralized Finance—A Multivocal Approach

The Blockchain Oracle Problem in Decentralized Finance - A Multivocal Approach

Two-Level Blockchain System for Digital Crime Evidence Management

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