What is 6 confirmations?

[houseofchill]

I read I have to wait 6 confirmations after getting a bitcoin to prevent a double-spend attack. But is that 60 minutes or it depends?  Once the wallet says balance is confirmed, is that 6 confirmations?

[redream]

I read I have to wait 6 confirmations after getting a bitcoin to prevent a double-spend attack. But is that 60 minutes or it depends?  Once the wallet says balance is confirmed, is that 6 confirmations?

Yes, once wallet says a balance is confirmed, that is 6 confirmations. However due to the nature of the blockchain, this could take any amount of time longer or shorter. It can be random, however the network will adjust (change difficulty) in order for the time of each confirmation to be around 10 minutes.

[FocusMedia]

Also depends on the size of the transaction, but generally it's around 40 minutes of 6.

[houseofchill]

Thanks! Questions get answered here fast.  Ok but does that mean if I pay with bitcoins in a restaurant that I'd have to stick around another 40-60 minutes after paying the bill so the owner can get their balance confirmed?

[FocusMedia]

Thanks! Questions get answered here fast.  Ok but does that mean if I pay with bitcoins in a restaurant that I'd have to stick around another 40-60 minutes after paying the bill so the owner can get their balance confirmed?

I mean, after 1 confirmation you're normally good to go, it's just how much really. 1 Bitcoin isn't much. Maybe if I was doing a 100 Bitcoin transaction I would wait for 6.

[redream]

Thanks! Questions get answered here fast.  Ok but does that mean if I pay with bitcoins in a restaurant that I'd have to stick around another 40-60 minutes after paying the bill so the owner can get their balance confirmed?

Usually the store owner would accept a transaction with 0 or 1 confirmations, as there is a relatively low (however still present) risk of a double spend. It really depends on the amount of risk the store owner is willing to take. This risk will lower as the power of the bitcoin network increases.

[anyroll]

Yea time varies greatly for transaction speed. On the larger end transactions you can wait more then an hour.

[DannyHamilton]

If the restaurant owner doesn't force you to sit around and wait for the settlement that happens with the credit card company at the end of the night when the money is finally deposited in their bank account, then I don't see why they'd make you sit around and wait for 6 confirmations.  Depending on the contract that the restaurant has with the credit card processor, credit card transactions can be reversed months later.  Do they make you sit around in the restaurant for months until they are sure you can't reverse the transaction?

At some point, a business owner decides that they are willing to take on a small risk of loss due to transaction reversal in exchange for the ease and convenience of accepting an electronic payment.  Many restaurants will likely be perfectly happy to accept a transaction with 1 confirmation.  In the future third party services may be created that will allow businesses to accept transactions instantly with minimal concern about double spends.

[shelfrazor]

 6 confirmations means the transaction has to be recorded in the blockchain 6 times.

[DannyHamilton]

6 confirmations means the transaction has to be recorded in the blockchain 6 times.

No.  No transaction is ever recorded in the blockchain more than once.

6 confirmations means that more 5 blocks have been solved by miners since the block that contains your transaction.

[shelfrazor]

 oh, ok. lol.

[duplex]

I don't think restaurants will require any confirmations. After all, someone could just run off without paying the bill. Why mess around with double spending?

[Stack]

Generally 1 confirmation is treated as the ok for a transaction working
But 6 confirmations is waited for, before trying to further spend.

For example transferring a balance to an exchange, with 1 confirmation they will usually include the coin in your balance, but not allow you to spend it until it has 6