Escrow
Bitcointalk · 2010-08-07 20:13:52 UTC
下面概述一种软件上可行的托管交易。这还没实现，我近期大概也没时间实现，只是让你知道什么是可能的。
基本托管：买家把一笔付款提交到托管中。卖家收到一笔钱在托管中的交易，但在买家解锁之前他花不掉。买家此后随时可以释放这笔付款，也可能永远不释放。这不允许买家把钱拿回去，但给了他一个选择：永远不释放，赌气把钱烧掉。卖家也有选择把钱退回给买家。
这个系统虽然不能保证双方不受损失，但它让作弊无利可图。
如果卖家不发货，他就拿不到钱。买家还是会损失这笔钱，但至少卖家没有骗他的金钱动机。
买家无法通过不付款获利。他拿不回托管的钱。他不可能因为资金不足而付不出。卖家能看到资金已锁定到他的密钥上，无法转给别人。
这时，经济学家会说，欺诈的卖家可能会开始谈判，比如"放款吧，我退你一半"，但到那时，信任已经所剩无几、怨恨却那么多，谈判不太可能发生。骗子既然已经在为行骗而食言，凭什么会守信用退你一半？我想对于不大的金额，几乎所有人光凭原则就会拒绝。
英文原文
Here's an outline of the kind of escrow transaction that's possible in software. This is not implemented and I probably won't have time to implement it soon, but just to let you know what's possible.
The basic escrow: The buyer commits a payment to escrow. The seller receives a transaction with the money in escrow, but he can't spend it until the buyer unlocks it. The buyer can release the payment at any time after that, which could be never. This does not allow the buyer to take the money back, but it does give him the option to burn the money out of spite by never releasing it. The seller has the option to release the money back to the buyer.
While this system does not guarantee the parties against loss, it takes the profit out of cheating.
If the seller doesn't send the goods, he doesn't get paid. The buyer would still be out the money, but at least the seller has no monetary motivation to stiff him.
The buyer can't benefit by failing to pay. He can't get the escrow money back. He can't fail to pay due to lack of funds. The seller can see that the funds are committed to his key and can't be sent to anyone else.
Now, an economist would say that a fraudulent seller could start negotiating, such as "release the money and I'll give you half of it back", but at that point, there would be so little trust and so much spite that negotiation is unlikely. Why on earth would the fraudster keep his word and send you half if he's already breaking his word to steal it? I think for modest amounts, almost everyone would refuse on principle alone.