> your code needs to trust an external system providing the data As for the reliability of external data sources to a contract running on Ethereum, there are m

> your code needs to trust an external system providing the data As for the reliability of external data sources to a contract running on Ethereum, there are multiple proposed solutions. One is to use some sort of reputation tokens similar to what Augur[1] - a prediction market built on Ethereum; employs. Another solution that was suggested by one of the co-founders of the Ethereum project is to use "Schelling points"[2] as guides since a large number of non-communicating reporters of events will most likely converge at what is closest to the truth[3]. > other people will honour the 'facts' decided by your program I don't really see that as a technical limitation of Ethereum. IANAL but, if the terms of the smart contract can be codified into a legal agreement, then the decisions of the program can be made enforceable by law. [1]: http://augur.link/augur.pdf http://augur.link/augur.pdf [2]: https://en.wikipedia.org/wiki/Focal_point_%28game_theory%29 https://en.wikipedia.org/wiki/Focal_point_%28game_theory%29 [3]: https://blog.ethereum.org/2014/03/28/schellingcoin-a-minimal-trust-universal-data-feed/ https://blog.ethereum.org/2014/03/28/schellingcoin-a-minimal...