Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Towards Trustworthy DeFi Oracles: Past,Present and Future   With the rapid development of blockchain technology in recent years, all
kinds of blockchain-based applications have emerged. Among them, the
decentralized finance (DeFi) is one of the most successful applications, which
is regarded as the future of finance. The great success of DeFi relies on the
real-world data which is not directly available on the blockchain. Besides, due
to the deterministic nature of blockchain,the blockchain cannot directly obtain
in-deterministic data from the outside world (off-chain). Thus, oracles have
appeared as a viable solution to feed off-chain data to blockchain
applications. In this paper, we carryout a comprehensive study on oracles,
especially on DeFi oracles. We first briefly introduce the application
scenarios of DeFi oracles, and then we talk about the past of DeFi oracles by
categorizing them into several types based on their design features. After
that, we introduce five popular DeFi oracles currently in use(such as Chainlink
and Band Protocol), with the focus on their system architecture, data
validation process,and their incentive mechanisms. We compare these present
DeFi oracles from their data trustworthiness,data source trustworthiness and
their overall trust models. Finally, we propose a set of metrics for designing
trustworthiness DeFi oracles, and propose a potential trust architecture and a
few promising techniques for building trustworthiness oracles.

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The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
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The categories of this paper are: quant-ph
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The categories of this paper are: q-alg
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The categories of this paper are: gr-qc
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The categories of this paper are: comp-gas
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The categories of this paper are: nlin
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The categories of this paper are: acc-phys
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The categories of this paper are: dg-ga