Is it still possible to double spend?

[Mcqueen44]

So as I see, more safely will be use 1 confirmation when using BTC pamyment on sites?

[1714731740]

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[1714731740]

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[1714731740]

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[thriftshopping]

Its actually more of a donation thing. Im not really selling anything.

What's the point of double spending a donation?

IDK. Maybe the creator of the project wants to forge donations on my site and withdraws?

This would not make any sense. If someone donates to your website then they are not receiving anything of value in return. Therefore it is impossible for you to wait for n confirmations because once you get as many confirmations you are not going to give the person potentially double spending anything of value

[nahtnam]

Its actually more of a donation thing. Im not really selling anything.

What's the point of double spending a donation?

IDK. Maybe the creator of the project wants to forge donations on my site and withdraws?

This would not make any sense. If someone donates to your website then they are not receiving anything of value in return. Therefore it is impossible for you to wait for n confirmations because once you get as many confirmations you are not going to give the person potentially double spending anything of value

No, its a site that allows other people to accept donations in bitcoins.

[serje]

Its actually more of a donation thing. Im not really selling anything.

What's the point of double spending a donation?

IDK. Maybe the creator of the project wants to forge donations on my site and withdraws?

This would not make any sense. If someone donates to your website then they are not receiving anything of value in return. Therefore it is impossible for you to wait for n confirmations because once you get as many confirmations you are not going to give the person potentially double spending anything of value

No, its a site that allows other people to accept donations in bitcoins.

Nice idea you have .... let us know when the site is ready ... I would like to try it

[nahtnam]

Its actually more of a donation thing. Im not really selling anything.

What's the point of double spending a donation?

IDK. Maybe the creator of the project wants to forge donations on my site and withdraws?

This would not make any sense. If someone donates to your website then they are not receiving anything of value in return. Therefore it is impossible for you to wait for n confirmations because once you get as many confirmations you are not going to give the person potentially double spending anything of value

No, its a site that allows other people to accept donations in bitcoins.

Nice idea you have .... let us know when the site is ready ... I would like to try it

Will do. I think ill stick with 0 confirmations and add some sort of mechanism that verifies everything before withdrawing.

[JerryCurlzzz]

You can have double-spending only if :
- the seller use a node server with no others nodes connected
- the buyer use ... the same node server
- the transaction is OK for both party with 0 confirmation

It's impossible.
In real life networking, you have 6-9 nodes to sprend the transaction ...

So its safe for me to accept 0 confirmations?

All reputable businesses will use 1. You don't truly have the coins until at least 1 confirmation.
Don't pull a Mt.Gox and leave yourself open with loose code. Protect yourself.

Uh.... ** Bitpay ** does zero-confirmation transactions. The dubious emphasis on confirmations is part of what kills the appeal of using bitcoin. This is not some scamcoin with a dead network. A simple code to do input analysis on a widely broadcast transaction and you are fine to accept 0 confirmations.

[shorena]

-snip-
Uh.... ** Bitpay ** does zero-confirmation transactions. The dubious emphasis on confirmations is part of what kills the appeal of using bitcoin. This is not some scamcoin with a dead network. A simple code to do input analysis on a widely broadcast transaction and you are fine to accept 0 confirmations.

Which is fine for a company like bitpay that can have multiple nodes online to test how good the propagation of the TX is and keep rebroadcasting it, but a little site (no offense nahtnam) thats accepting donations this might be a little to much to ask for.

-snip-
Will do. I think ill stick with 0 confirmations and add some sort of mechanism that verifies everything before withdrawing.

This sounds good. Confirm instantly (0 confirmations needed) and lets those receiving the donation wait a little longer (e.g. 6 confirmations). This gives those donating the good feeling instantly and those receiving the donation can probably wait an hour or two before they withdraw their money. Its FREE money I doubt anyone is going to get impatient about it.

[qwk]

Its actually more of a donation thing. Im not really selling anything.

What's the point of double spending a donation?

IDK. Maybe the creator of the project wants to forge donations on my site and withdraws?

That's very easy to work around.
Accept incoming donations with zero confirmations.
Only pay out to charities anything above 2 or more confirmations.

[serje]

This sounds good. Confirm instantly (0 confirmations needed) and lets those receiving the donation wait a little longer (e.g. 6 confirmations). This gives those donating the good feeling instantly and those receiving the donation can probably wait an hour or two before they withdraw their money. Its FREE money I doubt anyone is going to get impatient about it.

This is true! Just write in T&C that they can only withdraw after 6 confirmations! As this is free money for them they don't have the right to bitch about it! Only if they want to empty your wallet with double spend... so I guess 6 confirmations for withdrawing is perfect! As they can't say they have an emergency and they stay on the net to ask people for money! You call people for that and say I will pay back as soon as people will donate to me!

[98problems]

You can have double-spending only if :
- the seller use a node server with no others nodes connected
- the buyer use ... the same node server
- the transaction is OK for both party with 0 confirmation

It's impossible.
In real life networking, you have 6-9 nodes to sprend the transaction ...

So its safe for me to accept 0 confirmations?

All reputable businesses will use 1. You don't truly have the coins until at least 1 confirmation.
Don't pull a Mt.Gox and leave yourself open with loose code. Protect yourself.

Uh.... ** Bitpay ** does zero-confirmation transactions. The dubious emphasis on confirmations is part of what kills the appeal of using bitcoin. This is not some scamcoin with a dead network. A simple code to do input analysis on a widely broadcast transaction and you are fine to accept 0 confirmations.

It would still be possible to double spend a 0/unconfirmed TX, especially if you control a large amount of hashpower and are either running a pool or are solo mining.

An easy solution to the OP's problem would be to process payments to charities in batches with the payment going out 1 day after payment is received

[Wardrick]

Its actually more of a donation thing. Im not really selling anything.

What are the donations going to?