Block chain predicts machine
BlockChainOracle


Recently I learned a lot of block chain intelligence in the process of the project contract
Always in contact with the BlockChainOracle this noun
In many Chinese white paper, it is translated into block chain predicts machine
But all the year round to mix in the currency of the author, at first know very little is
The introduction on the net also is less, many don't speak understand
Even some wrong
So I again and again to find the information, consult technical bosses
Compiled a detailed article
Share with you
Sure finish will have a deep knowledge of prophecy machine

What is predicted that machine?
Predicting machine is actually a one-way digital agency
Can search and verification of real world data
And submit the information to the intelligent contract in the form of encryption
Predicting machine is block chain interaction with real world data interface
Chain in the world is like blocks a third-party data agent,



01


Simple
Let us, for example,

To us, for example:
Suppose now I was put in a little black house
I know almost nothing about what has happened to the outside world
Don't know if anyone outside, no one even call response
Only the man at the door outside tell me
I can learn that the outside change
Smart contracts like "I" in this case, it is no matter when and where to
Can't take the initiative to seek outward information
Only outside to inside information or data,
And predicted that machine is the at the door after receiving my request
Conveying messages and data from the outside of the

Although this analogy inaccurate
But means to predict machine is block chain and the connecting link between the real world
Can implement the data exchange tool
So the machine is not forecast, also does not have the function to predict the future

1: predicting machine doesn't have the ability to predict the future
2: predicting machine is connected to the real world with block chain link the world





02


Oracle
Block chain and predict machine


Why call predict machine?
An actor in Oracle is originated from ancient Greece myth
He can communicate with the gods of Olympus
And to convey the will of god to the people, and therefore has a "oracle, prophets, predict the meaning of"


The prophet
In the field of Internet
Assume a similar "communicator" identity machine
Called Oraclemachine (oracle in machine or predicted)
While in the field of chain blocks, named BlockChainOracle
Combined with the myth of its meaning and actual use
Thus translated into block chain forecast machine

Why need to predict machine block chain?
Now we need to understand is
Now all the male chain is a closed system
He can only read the data on the chain, is unable to perceive the real world
Mainly because the chain block can't initiate Networkcall (network)
Smart and chain contracts are passive receiving data

Second, smart contracts should be called executable scripts
It is not "smart" only under the condition of satisfy the corresponding
To reach the state trigger program
Ensure the implementation of intelligent contracts eventually need to participant's private key to sign contract,
Intelligent contract itself has no way to automatically perform

When the trigger condition of intelligent contract depends on the block outside the chain information
This information should be first records written to block chain,
The need to provide these blocks by predicting machine outside the chain of information,

Predict how the machine work
Here is the ideal prediction machine workflow
The user's smart Oracle request to chain contracts
Through the chain of API interfaces for external data
More precisely, the external data to the Oracle of the chain contract
And then you put the data to the user's intelligent Oracle contract agreement,



Maybe it is hard to understand
Because in the Internet, is very easy to call
Only need to write a call in your application code can
But block chain data interaction with the outside world
Do not conduct such operations

Application scenarios to predict the machine
Predicting machine as block chain with real world data interaction bridge
Application scenarios very much
Can say all need data and chain under the interaction of DApp all need to predict machine
Such as financial derivatives trading platform
Lending platform, express tracking/IoT, stable currency, gambling games, such as insurance, prediction markets
At present the main scene is DeFi

Predicting machine type
At present, predict machine has three types of
Software predicted machine, hardware predict machine and consensus machine

The software predicted machine
Through the API from a third party service provider or website to get the data
As the input data of intelligent contract
The most commonly used such as the weather data, the flight data, stock market data, etc.

Hardware machine prophecy
Usually forms on the Internet of things data collector,
Such as the front, for example, the traceability system, installed on the equipment of the sensor is the hardware machine,
Block chain technology is widely used in the field of Internet of things will produce a lot of hardware predicted machine
To predict the machine hardware core technology has nothing to do with the block chain
Form is more a sensor and data collector

Consensus predictions machine
Different from the front two predict machine centralized
Usually is also known as decentralized predicted machine
This machine through distributed participants to vote,
As a result of the existence of prophecy machine
In fact the more accurate definition of block chain should be: "to maintain trust machine",
Block chain itself does not generate trust
Trust the input comes from the "prophecy machine
"
Infrastructure, to predict the machine as a block chain is still in development, in the face of the physical world diversified situation remains a major challenge