4 ms·
As soon as your bitcoin node receives the signed transaction (should be seconds), approve the transaction, but listen for other spends of those same coins. Afte
by jeffasinger 14y ago
As soon as your bitcoin node receives the signed transaction (should be seconds), approve the transaction, but listen for other spends of those same coins. After a few seconds, the cost of double spending those coins would be basically the same as the reward for mining a block, so it's unlikely that someone would defraud you for something worth less than ~$2,000.
There's almost nothing you could be selling online that couldn't be reversed within an hour or so of the sale in the relatively rare cases of fraud, with the possibly exception of wire transfers of cash.
- deepblueocean 14y agoThis is just wrong - see the Hal Finney attack. Basically, an attacker can pre-mine a block with the double-spent coin in it but not announce it. Once an attacker spends the coin and gets something of value, they can immediately announce their block, pay the coin to themselves instead, and keep the goods. It's true that it would be hard to get a lot of value this way, but it's still the case that the person accepting the payment must be wary of the possibility and, as you say, be able to reverse the transaction if the coin ends up double-spent.