BTC Transaction time | Bitcointalksearch.org

shorena

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No I dont escrow anymore.

Quote from: CIYAM on September 28, 2014, 10:35:35 AM

Quote from: shorena on September 28, 2014, 10:32:50 AM

http://www.bitundo.com/

Assuming the website does what "it says it does" it still cannot "undo a confirmed tx" (only a 0 confirmation tx).

So the basic advice of "don't use 0 confirmations" remains.

Yep, exectly my point

Mabye I just got this:

Quote from: amaclin on September 28, 2014, 10:12:26 AM

Quote

you dont actually need to know someone running a mining pool as there are services out there for this.

There are no such services. Now. Point.

wrong.

CIYAM

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Ian Knowles - CIYAM Lead Developer

Quote from: shorena on September 28, 2014, 10:32:50 AM

http://www.bitundo.com/

Assuming the website does what "it says it does" it still cannot "undo a confirmed tx" (only a 0 confirmation tx).

So the basic advice of "don't use 0 confirmations" remains.

shorena

copper member

Activity: 1498

Merit: 1520

No I dont escrow anymore.

Quote from: amaclin on September 28, 2014, 10:12:26 AM

Quote

you dont actually need to know someone running a mining pool as there are services out there for this.

There are no such services. Now. Point.

Lets derail this thread even further...

http://www.bitundo.com/

amaclin

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Quote

I didn't check - but even if they are not in existence "today" that doesn't mean that they won't be readily available "tomorrow".

That's correct!

CIYAM

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Ian Knowles - CIYAM Lead Developer

Quote from: amaclin on September 28, 2014, 10:12:26 AM

There are no such services. Now. Point.

I didn't check - but even if they are not in existence "today" that doesn't mean that they won't be readily available "tomorrow".

amaclin

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Quote

you dont actually need to know someone running a mining pool as there are services out there for this.

There are no such services. Now. Point.

CIYAM

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Ian Knowles - CIYAM Lead Developer

Quote from: Brad Pitt on September 28, 2014, 10:09:28 AM

I'm pretty new to bitcoin but I have a question I'm unsure of. Can you spend bitcoin as soon as it is sent to you or do you have to wait for it to fully confirm? I've read different answers that you can and cant. Thanks.

I think that varies from "client to client" (the protocol won't stop it - but you'll end up with "stuck txs" due to the dependencies).

From memory the most recent versions of "bitcoin-core" won't use unconfirmed "inputs" (but don't quote me on that - as I am not 100% certain).

CIYAM

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Ian Knowles - CIYAM Lead Developer

Quote from: shorena on September 28, 2014, 10:07:46 AM

The sad thing is that you dont actually need to know someone running a mining pool as there are services out there for this. Thus, allways be sceptic when a TX has no fees Wink

E.g. bitundo

Not surprised - which is why accepting 0 confirmations is "not a smart idea" in general.

Brad Pitt

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I'm pretty new to bitcoin but I have a question I'm unsure of. Can you spend bitcoin as soon as it is sent to you or do you have to wait for it to fully confirm? I've read different answers that you can and cant. Thanks.

1MCLsSdL6NijcZFL2jQWo3oEvHWoez6uSU

shorena

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No I dont escrow anymore.

Quote from: CIYAM on September 28, 2014, 09:51:59 AM

Quote from: Minnlo on September 28, 2014, 09:47:11 AM

But the problem we are concerning here is the potential double spending attempts, which if success the transaction may never be confirmed.

Yup - the easiest way to "game" is to send a tx with "no fee" (that has reasonably aged inputs and a not too tiny output amount) through the "normal channels" (which looks legit but has "low priority") and then send the same tx with a "fee" (and of course a *different output address*) directly to a "friendly mining pool" (i.e. one that prefers fees over no fees) very shortly afterwards.

The sad thing is that you dont actually need to know someone running a mining pool as there are services out there for this. Thus, allways be sceptic when a TX has no fees Wink

E.g. bitundo

CIYAM

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Ian Knowles - CIYAM Lead Developer

Quote from: Minnlo on September 28, 2014, 09:47:11 AM

But the problem we are concerning here is the potential double spending attempts, which if success the transaction may never be confirmed.

Yup - the easiest way to "game" is to send a tx with "no fee" (that has reasonably aged inputs and a not too tiny output amount) through the "normal channels" (which looks legit but has "low priority") and then send the same tx with a "fee" (and of course a *different output address*) directly to a "friendly mining pool" (i.e. one that prefers fees over no fees) very shortly afterwards.

Minnlo

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Quote from: fathur01 on September 28, 2014, 09:43:03 AM

Quote from: Minnlo on September 28, 2014, 09:36:31 AM

So after all, accepting 0 conf. transaction isn't safe at all, even if the transacted amount is rather small and the transaction has enough fee?

if you send 1 btc with 0 fee it will still confirm eventually. But 0.001 with 0 fee wont confirm and will go back to the senders address, scamming the seller from his item.

But the problem we are concerning here is the potential double spending attempts, which if success the transaction may never be confirmed.

Minnlo

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Quote from: CIYAM on September 28, 2014, 09:38:03 AM

Quote from: Minnlo on September 28, 2014, 09:36:31 AM

So after all, accepting 0 conf. transaction isn't safe at all, even if the transacted amount is rather small?

It is always possible to "game" 0 confirmations - so yes you are taking the risk of getting played if you do this.

Of course this depends upon "what you are selling" (if it is a service like a VPS you can always *switch it off* when the payment later fails - but if it is a "coffee" then you "probably don't want it returned after it has been consumed").

I see. Thanks for your clarifications.
So, it seems the only safe way to handle coffee shop and supermarket payments is to do it through offchain transactions.

fathur01

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Quote from: Minnlo on September 28, 2014, 09:36:31 AM

So after all, accepting 0 conf. transaction isn't safe at all, even if the transacted amount is rather small and the transaction has enough fee?

if you send 1 btc with 0 fee it will still confirm eventually. But 0.001 with 0 fee wont confirm and will go back to the senders address, scamming the seller from his item.

CIYAM

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Ian Knowles - CIYAM Lead Developer

Quote from: Minnlo on September 28, 2014, 09:36:31 AM

So after all, accepting 0 conf. transaction isn't safe at all, even if the transacted amount is rather small?

It is always possible to "game" 0 confirmations - so yes you are taking the risk of getting played if you do this.

Of course this depends upon "what you are selling" (if it is a service like a VPS you can always *switch it off* when the payment later fails - but if it is a "coffee" then you "probably don't want it returned after it has been consumed").

Minnlo

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Activity: 868

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So after all, accepting 0 conf. transaction isn't safe at all, even if the transacted amount is rather small and the transaction has enough fee?

CIYAM

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Ian Knowles - CIYAM Lead Developer

Quote from: shorena on September 28, 2014, 09:28:15 AM

Yes, my problem is basically that for me a double spend would be if one of the TX had at least one confirmation, but I cant tell how common this idea is.

Small re-orgs (of 1-2 blocks) do happen fairly often but generally don't involve such "tx replacements" (although that of course *could happen*) this is why you should care about confirmations (the more valuable the tx the more you'd generally want to wait).

If I was say accepting BTC for something as valuable as a *house* then I'd probably want to wait for 100 confirmations (although maybe you think that would be "going overboard").

For a face-to-face situation involving even a few thousand dollars I would be basically happy with just a couple.

Topic: BTC Transaction time (Read 2240 times)