How can bitcoin be used in shops, if payments take so long to process?

[ranochigo]

As my online shopping experience, some sites requires no confirmation to the transaction. So since the tx appears on the mempool almost instantly after broadcasted, and it will detect that if it is a double spend (if not, then it is a real tx). So some shops may do this.

there already are shops that don't require you to wait for confirmations. you get what you buy instantly. but i don't think they will do the same if amount is higher than $20-$30

if we can have a very good regulation and services that take all the risk about a possible double spend when you perform a transaction, then there will be shops in the future who are willing to accept $200 worth of a transaction without any confirmation

the problem is having an authority that deal with this kind of stuf, a third party that connect the user to a shop, like coinbase, but coinbase still require confirmations, so a better thing than that

Bitpay. I have used them on various site and they don't seem to require any confirmations if the owner chooses to. If you wait for a few minutes and check for competing transactions, propagation and fees, I don't see why would you have much risk when accepting such transactions. The best way is to ensure that the transactions is in the mempool of the top pools and they have reasonable priority.

[RodeoX]

Bitpay. I have used them on various site and they don't seem to require any confirmations if the owner chooses to. If you wait for a few minutes and check for competing transactions, propagation and fees, I don't see why would you have much risk when accepting such transactions. ...

I think they just take the risk. The same is true for small credit card transactions. For example at McDonald's when you swipe your card there is no signature or pin number used because the chance of fraud and the stakes are so small. No criminal would orchestrate a fraudulent purchase of a hamburger, it would not be worth it. A double spend of bitcoin would require a lot of knowledge, set-up, and the chances of success would be small. It's just not a realistic threat.
Sure, if I were buying a car I would wait to see a few confirmations, but not for a sub-$100 purchase.

[Fat Ronaldo]

Payments take long? They're instant. Sometimes I think the people who ask this question have never actually sent bitcoins themselves.

[ranochigo]

Payments take long? They're instant. Sometimes I think the people who ask this question have never actually sent bitcoins themselves.

Even though double spending risk at no confirmation is little to none, the risk is still there. People don't understand how Bitcoin works and draw the conclusion that any no confirmation transaction have the risk of double spending. However, it is worth noting that in the event of 51% attack, transactions can be reversed relatively easily. It can be done but lots of computing power is needed to initiate such attacks. Many other methods still exist for transactions with no confirmations, all the seller have to do is to take precautionary measures to ensure the risk is minimal.

[bitnanigans]

Transactions are broadcast on the blockchain instantly. Payments only take a while to process if confirmations are required.

[98problems]

Transactions are broadcast on the blockchain instantly. Payments only take a while to process if confirmations are required.

well yeah but if they start making order and the confirmation arrives only after 60 minutes people can double spend bitcoins cant they?

[iram66680]

Transactions are broadcast on the blockchain instantly. Payments only take a while to process if confirmations are required.

well yeah but if they start making order and the confirmation arrives only after 60 minutes people can double spend bitcoins cant they?

Technically yes but practically, it's really hard. Once the transaction gets proporgated to a huge number of nodes and miners, they will reject any other transactions spending from the same input. Lest the miner uses replace by fee patch, once it has been relayed across the network and a reasonable fee included, miners would reject the next transaction spending the next input. To my knowledge, no miner with good amount of hashpower use that patch.

[bitbaby]

For smaller transaction I think shops won't mind and they will let you walk out with goods without any confirmations if your transaction has the right amount of fee and it is of 'High Priority' but for larger ones the shops might require you to wait for at-least one confirmation. Also you have to understand that shops have cameras and if someone does this, i.e. pays with bitcoin, walks out and perform a double spend, it will be considered stealing and if the shop owner complaints you will get charged, performing a double spend whilst shopping online anonymously is one thing but doing it face to face can have consequences.

But I think we're thinking too far here, Bitcoin is more suited for online transactions and this is why we need more online shops to start accepting bitcoin first because where I live I don't know any stores that accept bitcoins for face to face transactions.

[iram66680]

For smaller transaction I think shops won't mind and they will let you walk out with goods without any confirmations if your transaction has the right amount of fee and it is of 'High Priority' but for larger ones the shops might require you to wait for at-least one confirmation. Also you have to understand that shops have cameras and if someone does this, i.e. pays with bitcoin, walks out and perform a double spend, it will be considered stealing and if the shop owner complaints you will get charged, performing a double spend whilst shopping online anonymously is one thing but doing it face to face can have consequences.

But I think we're thinking too far here, Bitcoin is more suited for online transactions and this is why we need more online shops to start accepting bitcoin first because where I live I don't know any stores that accept bitcoins for face to face transactions.

What can you actually do with the footage, that's one thing. You can't go to the police and say this person stole something, they don't know which person you are talking about. If the double spend is successful, you wouldn't have any proof that double spend was conducted since the transaction will be dropped from the mempool.  In some places, Bitcoin isn't offically recognized as a currency and that is another thing.

[Rmcdermott927]

A payment takes 10 min to process. In what store can you buy something under 10 minute really?

Sometimes you have to wait 15 min at the tilt because the employee is a moron, if you could do that in 10 min i`d be very happy.

You just buy the stuff quick, pay for it, then put the bought stuff in a safe storage inside the magazine, and go looking at the other products until you wait for verification. Then after the verification is done, pickup your bought goods and leave.

It would change shopping habits, but whatever.

 No ,that would make people leave..Really once blockchain see's the transaction you are good .i have stood their and tried to double spend and never succeeded(Testing) So , if you really want bitcoin to be used by the masses . Maybe try going to a real store and spending some ?

The problem with that theory arises when someone "forgets" to attach a fee to the tx.    Try sending a no fee tx these days.   With the current tx volume on the network, it is damn near impossible to send a tx without fee.  It will get returned to sender within a day or so.

[dHe_zHiq]

A payment takes 10 min to process. In what store can you buy something under 10 minute really?

Sometimes you have to wait 15 min at the tilt because the employee is a moron, if you could do that in 10 min i`d be very happy.

You just buy the stuff quick, pay for it, then put the bought stuff in a safe storage inside the magazine, and go looking at the other products until you wait for verification. Then after the verification is done, pickup your bought goods and leave.

It would change shopping habits, but whatever.

 No ,that would make people leave..Really once blockchain see's the transaction you are good .i have stood their and tried to double spend and never succeeded(Testing) So , if you really want bitcoin to be used by the masses . Maybe try going to a real store and spending some ?

The problem with that theory arises when someone "forgets" to attach a fee to the tx.    Try sending a no fee tx these days.   With the current tx volume on the network, it is damn near impossible to send a tx without fee.  It will get returned to sender within a day or so.

transactions without fee fastest I've ever done takes about 6 hours. but now when I try it again,
it almost becomes impossible.

[DannyHamilton]

The problem with that theory arises when someone "forgets" to attach a fee to the tx.    Try sending a no fee tx these days.   With the current tx volume on the network, it is damn near impossible to send a tx without fee.  It will get returned to sender within a day or so.

transactions without fee fastest I've ever done takes about 6 hours. but now when I try it again,
it almost becomes impossible.

If you both are so sure that a transaction without a fee will be returned to you, then I'd like to propose a challenge to you.  Let's see you put your money where your words are:

I'll provide you a bitcoin address of mine.  You send 1 BTC to that address without a fee.  Then double spend that same input back to an address that you control (or wait for it to be "returned to sender").

If you can keep the transaction from being confirmed to my address, I'll send you an extra bitcoin as a reward for your effort.

If you fail to keep the transaction from being confirmed to my address, then I get to keep the bitcoin.

So, if I'm right, I gain 1 BTC from you.  If you're right, you get your bitcoin back and you gain 1 BTC from me.

Should be the easiest $250 you'll ever make.  Right?

[RealBitcoin]

A payment takes 10 min to process. In what store can you buy something under 10 minute really?

Sometimes you have to wait 15 min at the tilt because the employee is a moron, if you could do that in 10 min i`d be very happy.

You just buy the stuff quick, pay for it, then put the bought stuff in a safe storage inside the magazine, and go looking at the other products until you wait for verification. Then after the verification is done, pickup your bought goods and leave.

It would change shopping habits, but whatever.

 No ,that would make people leave..Really once blockchain see's the transaction you are good .i have stood their and tried to double spend and never succeeded(Testing) So , if you really want bitcoin to be used by the masses . Maybe try going to a real store and spending some ?

The problem with that theory arises when someone "forgets" to attach a fee to the tx.    Try sending a no fee tx these days.   With the current tx volume on the network, it is damn near impossible to send a tx without fee.  It will get returned to sender within a day or so.

transactions without fee fastest I've ever done takes about 6 hours. but now when I try it again,
it almost becomes impossible.

I did a transaction once without a fee it took me 1-2 days to confirm, it was pretty annoying, but then again a 0.0001 fee is not the end of the world.