why bitcoin transaction to be confirmed twice?

[RENATA612]

why every transaction always have to wait for confirmation twice, is not that enough to occupy our time?
but on the other hand site already exists in the transaction does not require confirmation? it faster and certainly better

What do you think about this, and have you do a transaction without waiting for confirmation? let's share your thoughts

[BrewMaster]

let's share your thoughts

share my thought!!
it is the protocol.
an unconfirmed transaction is not yours until it is confirmed. otherwise it can be double spent and you won't get your money.

1 confirmation means there is very little possibility of double spending.

more than 1 means there are enough blocks mined after your transaction that it becomes extremely hard and expensive to double spend which means it is practically impossible.

next time read wiki, or bitcoin.org for things as simple as this, they explain things way better than we can in a comment.
https://en.bitcoin.it/wiki/Confirmation
https://bitcoin.org/en/you-need-to-know#instant

[shinratensei_]

To prevent the double spend but there is some kind of the double transaction.
race attack, finney attack and 51% attack.
You will need a single confirmation to prevent the race attack, and 5 minimum confirmation to prevent the finney attack.
Read this.
https://dl.dropbox.com/u/3658181/PiotrPiasecki-BitcoinMasterThesis.pdf

[zeze18]

so far I have transactions with bitcoin never without confirmation, and two confirmation I think it's not too bad, maybe we all hope that one day there was no confirmation again in bitcoin transaction,

[amacar2]

so far I have transactions with bitcoin never without confirmation, and two confirmation I think it's not too bad, maybe we all hope that one day there was no confirmation again in bitcoin transaction,

This is not going to happen because bitcoin network is not designed like other centralized payment processors where transactions doesn't require any network confirmation but waiting for few minutes to get your transactions confirmed is better than chargebacks you have with other processors even after few months.

[Capradina]

Indeed this is now a major problem that exists in the bitcoin is on the transactions that we do all the time, and this can make us get the loss if the transaction must wait for confirmation first. One thing about the site that does not make it a rule to wait until confirmation is a beneficial thing for us, but it's all bad impact can provide on site owners when they don't immediately get a confirmation the same day or even get their losses when a transaction they do turns out to be cancelled (due to the already long waiting for confirmation)
 

[SONG GEET]

Indeed this is now a major problem that exists in the bitcoin is on the transactions that we do all the time, and this can make us get the loss if the transaction must wait for confirmation first.

If you pay enough fees than this is not a big problem, many people try to save few satoshi in fees being greedy and get their transaction stucked in mempool for many hours.

Bitcoin transaction need confirmation to protect receivers/merchants from being scammed with double spending attacks. Number of confirmation needed varies but 1 confirmation is enough if transaction amount is not very big.

[romero121]

This makes the charge back feature get disabled. Only way is to get received if the receiver wishes once after sending. The confirmation makes it a trust of receiving it when several transactions take place within the same network with different time zone. This makes it effective when more miners give confirmation.

[AngelSky]

This makes the charge back feature get disabled. Only way is to get received if the receiver wishes once after sending. The confirmation makes it a trust of receiving it when several transactions take place within the same network with different time zone. This makes it effective when more miners give confirmation.

Its get two confirmation because of blocks need to be mined to right? Usually first confirmation will get with in 20 minutes with the minimum required fees. After the 2nd confirmation you may see the payment in your wallet. Blocks take some time to miner the btc. This is the reason bro.

[bitcampaign]

so far I have transactions with bitcoin never without confirmation, and two confirmation I think it's not too bad, maybe we all hope that one day there was no confirmation again in bitcoin transaction,

yes I agree in this case, I think this is a way to overcome the problem of tissue bitcoin bitcoin transactions fully and raise above 1 MB per block in mining is something that is silly: P

[pooya87]

This makes the charge back feature get disabled. Only way is to get received if the receiver wishes once after sending. The confirmation makes it a trust of receiving it when several transactions take place within the same network with different time zone. This makes it effective when more miners give confirmation.

Its get two confirmation because of blocks need to be mined to right? Usually first confirmation will get with in 20 minutes with the minimum required fees. After the 2nd confirmation you may see the payment in your wallet. Blocks take some time to miner the btc. This is the reason bro.

it depends on a lot of factor.
if you have high fees and blocks are mined every 10 minutes you get 1 confirmation every 10 minutes. and you should see the payment in your wallet even without confirmation but most modern wallets give you some sign that it is not confirmed.

but what happens in reality is that you include different amounts of fee so you get different priorities and with memory pool being full of spam, your transaction can take a long time or never gets confirmed.

also blocks aren't exactly mined every 10 minutes, that is an average number it can be 1 second after your transaction is broadcast(ed?) or 1 hour.

[Xester]

why every transaction always have to wait for confirmation twice, is not that enough to occupy our time?
but on the other hand site already exists in the transaction does not require confirmation? it faster and certainly better

What do you think about this, and have you do a transaction without waiting for confirmation? let's share your thoughts

Transaction confirmations are made to protect us from double spending. The more confirmations there are the safer and successful the transactions are. But the number of confirmations depends on what kind of site or wallet is receiving. There are sites that accepts bitcoin even if there is only 1 confirmation but there are very strict sites that requires six confirmations or more.

[Kakmakr]

I see confirmations like this. We do not have a central organization managing the financial ledger on our behalf, so we have to trust a decentralized system, where people validate your transactions. So if 1 person validated your transaction, it might not be enough, because this person might be a bad actor.

If 2 or more people validate the transaction, you would feel comfortable to acknowledge that this money is not spend twice.  

[bitcampaign]

I think he meant is why every site and receive bitcoin should use the requirements until 1 or 2 confirmation, so like this there are several sites that are already using zero confirmation for their users to deposit bitcoin so it does not make users wait for it even though the transaction will be confirmed and require a long time, users still get bitcoin them, for example on their account at trading site, we see a lot of full transaction lately has not been confirmed whether the attack spammers in network transactions bitcoin, so if I go to a coffee shop and buy coffee warmer by paying bitcoin then I was asked to wait 1 confirmation about 30 minutes, what do I have to wait that long to get my coffee, then what if the transaction I get first confirmation up to 2 days or I chose to use high transaction costs to get a quick first confirmation probably half the price of a cup of coffee

I just mention one that is the site whaleclub.co
I look at their site using a zero confirmation, so when I make a deposit and send bitcoin we can already see bitcoin on our account there and do the trade, I know the transaction bitcoin I would soon be confirmed within a few tens of minutes or a maximum of two days, but what as our users have to wait for the trade on their website until bitcoin transactions we get one or two confirmation while we still trade in their sites.

[TheGodFather]

why every transaction always have to wait for confirmation twice, is not that enough to occupy our time?
but on the other hand site already exists in the transaction does not require confirmation? it faster and certainly better

What do you think about this, and have you do a transaction without waiting for confirmation? let's share your thoughts

Well, its all about security, you cannot forfeit or rollback once it was starting to process. What if you sent them into wrong address ? Or you sent them an incorrect number ? Well, that makes sense thou. We need to stregthen our security about this matter because its so crucial, there are a lot of hackers trying to crack the server, trying to get some free bitcoins, doing all their best to steal some money.

[danherbias07]

The answer is already up there to the "Why confirm twice" the link is also provided for better explanation.
Now what could be the next question or what could be the real question that he have in mind.
It think it is "Why not just one?" "Is that possible?" If there will be only one confirmation, it will be easy for attackers.

Bitcoin Wiki:

"An attacker that controls more than 50% of the network's computing power can, for the time that he is in control, exclude and modify the ordering of transactions. This allows him to:

Reverse transactions that he sends while he's in control. This has the potential to double-spend transactions that previously had already been seen in the block chain.
Prevent some or all transactions from gaining any confirmations
Prevent some or all other miners from mining any valid blocks"

Bitcoin Wiki:

"To be secure against double spending, a transaction should not be considered as confirmed until it is a certain number of blocks deep."