image description
Tradingview：Link/USDT vsBTC/USDT
Any currency that goes out of this trend deserves our further attention.
The section where ChainLink is located is the "oracle machine" that the friends don't know much about. When I first started speculating in coins, I was stunned when I heard this word.
image description
Top 10 Market Value Digital Currency Changes (2013-2019)
The accurate definition of Augur is a forecasting project, in short, "spinach", with the attribute of "oracle machine". As a forecasting project, it needs to input the results of the external world to determine the winner of the forecasting project. The input method it adopts is "group wisdom", that is, what everyone thinks is right is right.
What is an oracle?
The mechanism by which information outside the blockchain is written into the blockchain is generally called an oracle mechanism.
The blockchain is a deterministic and closed system environment. At present, the blockchain can only obtain the data in the chain, but not the real world data outside the chain. The blockchain and the real world are separated.
The blockchain is a deterministic and closed system environment. At present, the blockchain can only obtain the data in the chain, but not the real world data outside the chain. The blockchain and the real world are separated.
The execution of a general smart contract requires a trigger condition. When the trigger condition of a smart contract is external information (outside the chain), an oracle must be required to provide data services, and the real-world data is input into the blockchain through the oracle, because Smart contracts do not support external requests.
Oracle Workflow
This is the ideal workflow of the oracle machine, that is, the user's smart contract sends the request to the Oracle contract on the chain, and obtains external data through the API interface off the chain. More precisely, the external data is sent to the Oracle contract on the chain, and then Oracle The contract then sends the data to the user's smart contract.
Classification of Oracles
According to different sources of trust, today's mainstream oracle machines can be divided into the following two categories:
1. Centralized oracles, such as Provable (formerly Oraclize).
2. Distributed oracles, such as ChainLink, DOS, Band.
image description
Provable work structure diagram
Relying on Amazon AWS services and TLSNotary technology, Provable is a provably honest oracle service, but it is centralized, currently only available on the Ethereum network, and has a high gas fee. But it does not prevent it from being the most popular oracle service at present, probably because there is no other better choice.
Proving data integrity off-chain is critical. Two common data authentication methods are authenticity proof (authenticity proof) and Trusted Execution Environment (Trusted Execution Environment, TEE).
There is also MakerDAO in the centralized oracle machine, which is dominated by Maker and includes the oracle model of 0x, dYdX, Set Protocol, Gnosis and other designated price feeding institutions. The center here is the trusted alliance.
Decentralized Oracle
What the blockchain needs to solve is the trust problem. Centralized oracle machines cannot meet the needs of blockchain products in this regard. Therefore, the demand for distributed oracle machines will become more and more vigorous with the development of public chains.
image description
ChainLink
ChainLink working diagram
image description
DOS
DOS working diagram
DOS Network is a Layer-2 oracle solution. It deploys a lightweight smart contract on the chain, and a p2p network off the chain. VRF+zkSNARK technology is used for the selection of bookkeeping nodes, and threshold signatures are used for data verification. The way to ensure decentralization and data security, and to achieve rapid response. It can be adapted to all mainstream public chains, such as Ethereum, EOS, TRON, and Zilliqa.
image description
Band
Band working diagram
Band Protocol is a protocol on Layer-2 of the blockchain, which can connect downwards to BTC, Ethereum, EOS and other networks. Connect different data sets to Dapp through BandProtocol.
The data set can be regarded as an independent community autonomous economy. Community members use the data set token (DT) to vote to select the data provider that the community considers excellent. When Dapp uses the data provided by the data provider , data providers and community members will be rewarded accordingly.
image description
Band connection curve function
Those who have played Bancor should have a better feeling for this kind of picture. That is, as the supply of sub-tokens increases, the price of sub-tokens will continue to rise. This gives players room to speculate.
image description
Summarize
Summarize
Remarks: The current price is unified as the closing price on October 11, 2019
At present, the market value of Link is the 15th. Whether Band and DOS can catch up with its predecessors remains to be seen.
Although the market value of DOS is very low, it is a pity that it is not listed on exchanges with better liquidity.
After all, in the currency circle where storytelling is the core, exchanges, as the most important part of liquidity, are almost the most important considerations.
And Band has not been raised since the IEO went online. I don’t know if Gouzhuang is lowering the receipts. MATIC had a similar operation before this, and it only started to explode two weeks after it went online. The current market value of Band is 7.5 million US dollars. According to our statistics before, according to the current market traffic, the ceiling of most IEO currencies is around 25 million US dollars.
The sudden emergence of Link has made the market pay more attention to the field of oracle machines. The blockchain world cannot be independent from the real world, and the oracle machine, as the most important bridge, will definitely have its place in this market. Let's keep an eye on this area.
