Trustworthy Blockchain Oracles for Smart Contracts

With the issuance of Bitcoin, blockchain technology has become more and more popular, and more and more well-known cryptocurrencies have been born. However the blockchain technology does not stop there, it can also be regarded as a very secure database. And Ethereum is a big pusher to promote the development of blockchain. It has developed the smart contract, which allows users to conduct secure transactions without a third party and avoid mutual mistrust between the two parties. With the development of blockchain, it is now possible to connect to the outside world through the API provided by the web service, which is called an Oracle. When a smart contract calls function, external data can be returned to the smart contract through the API. Such as obtaining the temperature of a certain country or obtaining the exchange rate of the current cryptocurrency. Now, oracle is mainly divided into two ways, through decentralization and centralization return data to the contract. However, the former method used by the oracle has little credibility for data collection, the latter is relatively slow in obtaining data return. This manuscript will update and optimize these parts, and hope to achieve a balance between the two. Finally, hope that more DAPP (decentralized applications) of the blockchain will be generated and the technology will be implemented. Chemical applications are more reliable.