Bitcoin Confirmations & Double Spending

[Zilarion]

I have a question that just popped into my mind.
We only "confirm" a transaction after 6 confirmations have been made on the said money, right?

Now, however - we also have that bitcoin payments are instant. Now the question here is, how can we make sure no one just pays in a shop or something similar, give said person the goods purchased and then find out later that the transaction would actually be denied (due to double payments or something similar)?

Can someone shed some light on this question?

[cr1776]

Take a look at this link.  ;-)

https://en.bitcoin.it/wiki/Double-spending

I have a question that just popped into my mind.
We only "confirm" a transaction after 6 confirmations have been made on the said money, right?

Now, however - we also have that bitcoin payments are instant. Now the question here is, how can we make sure no one just pays in a shop or something similar, give said person the goods purchased and then find out later that the transaction would actually be denied (due to double payments or something similar)?

Can someone shed some light on this question?

[ShireSilver]

Take a look at this link.  ;-)

https://en.bitcoin.it/wiki/Double-spending

It should be noted (and hopefully fixed on the wiki) that the Race Attack is not strictly speaking a double spend. It is a zero confirmation exploit that is basically the same as writing a check that will bounce. The business solutions that will solve/prevent this will likely be similar to what businesses use now, and will not be perfect but will probably be good enough.