| But the trust that a bitcoin transaction is final isn't enough trust to make an exchange! Lets say you and I decide right now that we're going to use these comments to make an exchange. I will give you $5 of bitcoin in exchange for you mailing me a postcard. Now what? How do we proceed in a meaningful manner? How do we go about making that exchange happen if we assume that either party is self-interested, and not interested in actually completing the deal? If I send the bitcoin first? - the second it hits your account you know for sure it's yours: No need to bother sending the postcard - that's just cash out of your pocket. If you mail the postcard first? - Well, job's done for me, no need to send any bitcoin at all. What if we both agree that we trust Bob, and you send him the postcard, and I send him the bitcoin, and he only forwards them along after he gets both? - Oops, now Bob can do all those things you complained about letting the bank do! He can send that bitcoin back and I won't ever get a postcard. He can mail the postcard back and you won't ever get any bitcoin (Transaction reversed!). Worse, he can take anything you give him and do what he wants while he has it (like disappear!) - or hold them much longer than you'd like after he gets them. (Freeze it). How do you get your stuff back from Bob? Same way you would from a bank - appeal to the government. Basically - Bitcoin without enforcement is only a ledger. The thing that keeps it in check with reality is an appeal to an authority somewhere, who provides trust that both parties in an exchange aren't getting screwed. |
Correct. Who said it was?
"How do we go about making that exchange happen if we assume that either party is self-interested, and not interested in actually completing the deal?"
We don't make that exchange in that case. Or like you mentioned we both acknowledge that we don't trust each other and get a trusted third party involved who we both trust more that the each other. No payment method is immune to this. Notice though that regardless of how much trust that we have or don't have for each other we can both trust that if you do send me $5 of Bitcoin I will receive it. Provided I've taken the necessary steps the transaction will not be reversed. Also note that if I wish I can also be certain that no one can erase whatever I rightfully claim is mine from the ledger or transfer it to another address once I have received it. This cannot be said for any non crypto digital payment system currently.
Bitcoin is a shared digital ledger hosted on a transaction network that is not controlled by a single trusted third party. The thing that keeps the ledger in check with reality is the correctness that it guarantees to those who are using the network to send and receive payments.
If you say you are going to send me a 1700 sats to post a postcard to you and I deliver as promised but in reality you don't perform your part of the deal the ledger is still correct. You still owe me 1700 sats according the deal we made and I can confirm this by checking the ledger. The ledger itself does not know about the deal we made but we both know we made a deal and according to that deal you still owe me 1700 sats. Now with a traditional bank what happens if you claim you sent it and the bank says you didn't. How can I verify that the transaction took place? I can't. I have to trust what you or the bank tell me and I don't know who is telling the truth. Maybe the transaction got lost. Maybe you didn't send it. There is no way to discover the reality of the situation without having to make an uninformed choice about who I trust.
At present Bitcoin is still clunky and has many issues both technical and non-technical to overcome. It is unknown whether these issues can or will be overcome. It has a far way to go if it is to realise the creators vision in a meaningful way by gaining mainstream adoption and use as "digital cash".