参考

[1] http://www.oraclize.it/
[2] https://tlsnotary.org/
[3] https://tlsnotary.org/pagesigner.html
[4] https://bitcointalk.org/index.php?topic=301538.0
[5] http://hackingdistributed.com/2017/06/15/town-crier/
[6] https://www.cs.cornell.edu/~fanz/files/pubs/tc-ccs16-final.pdf
[7] https://www.crowdfundinsider.com/2018/04/131519-vitalik-buterin-outlines-off-chain-ethereum-smart-contract-activity-at-deconomy/
[8] https://github.com/Azure/azure-blockchain-projects/blob/master/bletchley/EnterpriseSmartContracts.md
[9] https://people.cs.uchicago.edu/~teutsch/papers/truebit.pdf
[10] https://link.smartcontract.com/whitepaper
[11] https://blog.ethereum.org/2014/03/28/schellingcoin-a-minimal-trust-universal-data-feed/
[12] http://people.cs.uchicago.edu/~teutsch/papers/decentralized_oracles.pdf
[13] https://developers.thomsonreuters.com/blockchain-apis/blockone-iq-ethereum
[14] https://www.realitykeys.com