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Bitcoin => Bitcoin Discussion => Topic started by: wscott on September 27, 2010, 08:22:49 PM



Title: Time to receive payment?
Post by: wscott on September 27, 2010, 08:22:49 PM
OK I have read the wiki and other posts and I don't see this addressed anywhere.

Because of the way payments are validated it seems like any online payment using bitcoins will involve a time lag to verify the payment.
What do people do currently, wait until a payment is N blocks from the tip of the chain?  How long does that take? minutes? a couple hours?

It seems more some uses this would be a downside of bitcoins.  But then again I suspect most places that want a fast turnaround will be doing micropayments and then the seller can just take the risk for good service and just shutdown the user later if the payments don't end up being cleared.

Am I missing something?

-Wayne


Title: Re: Time to receive payment?
Post by: jimbobway on September 27, 2010, 08:54:28 PM
2 confirmations take a min or two min. the more confirmations the better.


Title: Re: Time to receive payment?
Post by: FreeMoney on September 27, 2010, 08:56:00 PM
2 confirmations take a min or two min. the more confirmations the better.

Huh?

Why not say it takes 1 second?


Title: Re: Time to receive payment?
Post by: wscott on September 27, 2010, 09:03:52 PM
I just noticed the snack machine thread: http://bitcointalk.org/index.php?topic=423.0


Title: Re: Time to receive payment?
Post by: nelisky on September 27, 2010, 09:04:37 PM
2 confirmations take a min or two min. the more confirmations the better.

Huh?

Why not say it takes 1 second?

Hehe, two confirmations take 2 blocks' time. The expected average is 6 blocks per hour, but that doesn't mean there will be one block every 10 minutes, rather difficulty increases every now and then based on the average blocks created in the last iteration.

It really is impossible to define a specific timeline, but the client does get almost immediate notice that a transaction is on the way. If it trusts that information blindly and is thus open to double spending attacks, or it waits for as many confirmations as it sees fit depends on you, the developing party, but two blocks in a min or two I don't think I've see so far :)


Title: Re: Time to receive payment?
Post by: FreeMoney on September 27, 2010, 11:49:43 PM
but two blocks in a min or two I don't think I've see so far :)

It happens, but it is misleading to say it it takes a few minutes. Average time is 10 minutes per confirmation, with wide variation.


Title: Re: Time to receive payment?
Post by: MoonShadow on September 28, 2010, 12:57:40 AM


Am I missing something?

-Wayne

No, it looks like you pretty much got it.  The client assumes that any coins sent are from an untrusted sender, so does not consider them mature for 200 blocks or so; basicly the next day.  But the receiver should be able to consider them good on his or her own faith of the sender.


Title: Re: Time to receive payment?
Post by: lfm on September 28, 2010, 06:03:37 AM


Am I missing something?

-Wayne

No, it looks like you pretty much got it.  The client assumes that any coins sent are from an untrusted sender, so does not consider them mature for 200 blocks or so; basicly the next day.  But the receiver should be able to consider them good on his or her own faith of the sender.

Actually the current client considers regular transactions as "unconfirmed" for just 6 blocks (nominally 1 hour). You can still spend them before they are confirmed and if there is a problem then your dependent transactions will remain unconfirmed too.

The special transactions for newly generated 50 coin creation transactions are held back for 120 blocks (20 hours). You cannot spend these till they are released.


Title: Re: Time to receive payment?
Post by: MoonShadow on September 28, 2010, 01:27:47 PM


Am I missing something?

-Wayne

No, it looks like you pretty much got it.  The client assumes that any coins sent are from an untrusted sender, so does not consider them mature for 200 blocks or so; basicly the next day.  But the receiver should be able to consider them good on his or her own faith of the sender.

Actually the current client considers regular transactions as "unconfirmed" for just 6 blocks (nominally 1 hour). You can still spend them before they are confirmed and if there is a problem then your dependent transactions will remain unconfirmed too.

The special transactions for newly generated 50 coin creation transactions are held back for 120 blocks (20 hours). You cannot spend these till they are released.


Thanks for the correction.