暗号証券
スマートコントラクト以外だと、暗号証券が重要。http://www.reddit.com/r/Bitcoin/comments/2rsv60/patrick_byrne_has_let_it_slip_that_medici_will/
Reality Keys。https://bitcointalk.org/index.php?topic=423638
http://bitcoinist.net/reality-keys-a-certificate-authority-for-facts/
http://youtu.be/mD4L7xDNCmA
http://www.coindesk.com/reality-keys-bitcoins-third-party-guarantor-contracts/