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Re:Ask HN: What was impossible earlier that is easy in the B... by ryanlol on Friday June 30, 2017 @01:42PM (#14672363)
Edited the comment to include verification almost simultaneously with your post :)

But yeah, obviously as the transaction value goes up the merchant will need to wait a few more seconds to counter doublespend attacks.

>You must submit it to the network

Not necessarily true, ideally the customer doesn't need internet connection and just transmits the signed transaction to the PoS.

>and the merchant must be reasonably confident that it will be accepted in a block as-is and that the block will not be orphaned

First of which can be verified very fast by a computer. I believe orphaned blocks are rare enough that they're mostly a non-issue.

I guess it's important to point out that in practice most Bitcoin ATMs I've used did 0-confirmation transactions up to 1000 euros after only a few second wait, so it's not like all bitcoin merchants suck.

Re:Ask HN: What was impossible earlier that is easy in the B... by ceejayoz on Friday June 30, 2017 @01:47PM (#14672408)
The average confirmation time for a Bitcoin transaction was 400+ minutes recently (and is still around an hour even now). https://blockchain.info/charts/avg-confirmation-time?daysAve...
Re:Ask HN: What was impossible earlier that is easy in the B... by ryanlol on Friday June 30, 2017 @03:42PM (#14673191)
Yes, but you don't need more than 20-30 seconds to be confident that a transaction isn't a doublespend attempt.

After that it's only about checking if the fee is high enough.

Re:Ask HN: What was impossible earlier that is easy in the B... by ceejayoz on Friday June 30, 2017 @04:50PM (#14673521)
> After that it's only about checking if the fee is high enough.

Which can take up to 72 hours, right?

Re:Ask HN: What was impossible earlier that is easy in the B... by ryanlol on Friday June 30, 2017 @06:35PM (#14673970)
No, you just check if the fee per KB is more than x. Where x is a fee that is likely enough to confirm. This is practically instant.
Re:Ask HN: What was impossible earlier that is easy in the B... by ceejayoz on Saturday July 01, 2017 @09:25AM (#14677009)
I'm not sure "likely enough to confirm" is going to go over all that well with many merchants, particularly when that chart shows the price-per-byte jumps all over the place rapidly.