That works, but it works without bitcoin. The idea the article was putting forth is that you could use bitcoin scripts to change property ownership The point i

That works, but it works without bitcoin. The idea the article was putting forth is that you could use bitcoin scripts to change property ownership The point is you can't, as the article proposes, create a bitcoin scripted loan where if I default on the loan, authorization message/transaction gets sent (because that message must be signed with a private key that the network does not have) . What you could do, in a world where bitcoin script is far more powerful, is give your bank a transaction that says this transaction is only valid if I didn't pay loan x(where x is some bitcoin contract loan) and if it is valid, then the bank has access to my car. When this transaction validates according to network consensus, the car would hand over control. This requires,however, that the car can make the validity judgment. Which means the car has to understand the bitcoin protocol and probably have access to the transaction records/blocks.