Don't accept 0 confirmation tx

[Bitcoin577]

As a newbie I am very happy to have lessons like this because these are going to help in future as reading here many scams and cheats happening with different peoples here in crypto world but this surely going to help many newbies because minimum 1 to 3 confirmations are ok for any payment but never go with 1 confirmation as this can give you shock and you can lost your hard earned funds thanks @RapTarX.

[nc50lc]

But what I can't manage to see again is their price to confirmation model they have done in that forum. It sorta goes like this.
0-1 Confirmations - up to 10$

Hmm, since it's also a forum, you can't always trust a post from a random user.

Or maybe it's for a gambling/exchange that accepts 0-confirmation deposits that has some safeguarding against double-spend attempts like
not accepting RBF txns, should have optimal fee and no withdrawals until the deposit is confirmed.

Care to link the thread where it was posted?

[o_e_l_e_o]

Technically, it is not possible to reverse a transaction which has been confirmed and included into the valid chain asides with an attack on the network.

Technically, it is. Occasionally the network experiences what is called a stale block. This is when two blocks are mined in very close succession. The first block isn't finished being broadcast round the network when the second block is also broadcast round the network. Some nodes accept the first block, and some accept the second. The conflict is only resolved when the next block is mined, and whichever block it was built on top of becomes the accepted block, with the other one being rejected and becoming a state block.

Now, usually any transactions which were included in stale block would also be included in either its replacement or the next block, and so wouldn't be reversed, but it is possible for a transaction not to be included and therefore go from 1 confirmation back to 0.

Although the transaction is reversed (going from 1 confirmation back to 0), it is not cancelled. The transaction will still exist in the mempool to be picked up by some future block, unless someone successfully double spends or replaces it.

[pooya87]

Yeah I have found several threads from stackexchange saying that 6 confirmations is the rule of thumb when it comes to how many confirmations needed in order for us to say that the transaction is secure and somehow irreversible. But what I can't manage to see again is their price to confirmation model they have done in that forum. It sorta goes like this.

0-1 Confirmations - up to 10$
3 Confirmations - 100$
6 Confirmations - 10,000$

The numbers above are made up but these is how they made the model explaining why these prices of transactions are safe depending on the number of confirmations.

again you can't just give raw numbers based on a single factor while there are multiple important ones to consider. these numbers you posted here are for the case when the user is running a full verification node and the network is healthy (there is no forks planed, etc.) read my comment in first page for details: https://bitcointalk.org/index.php?topic=5279776.msg55311829#msg55311829

[robelneo]

Check this thread- https://bitcointalk.org/index.php?topic=5279758.0
OP has been scammed because they accepted tx without a single confirmation. It's possible to manipulate a tx in such cases where scammer will send you the fund and make sure they have received what they have paid for and later they will create another tx with higher fee with the same input. The later tx will get confirmed and yours one will be invalid.
Therefore, don't accept zero confirmation tx. Wait for at least 1 confirmation.

Based on that story OP is a seller and he accepts Cryptocurrency for payment to his product, he is a newbie seller and naive, he should know how transaction works, he should have wait for the right number of confirmation before he send the product, every coin has a required number of transactions and he should be aware of that.

[casperBGD]

Check this thread- https://bitcointalk.org/index.php?topic=5279758.0
OP has been scammed because they accepted tx without a single confirmation. It's possible to manipulate a tx in such cases where scammer will send you the fund and make sure they have received what they have paid for and later they will create another tx with higher fee with the same input. The later tx will get confirmed and yours one will be invalid.
Therefore, don't accept zero confirmation tx. Wait for at least 1 confirmation.

Based on that story OP is a seller and he accepts Cryptocurrency for payment to his product, he is a newbie seller and naive, he should know how transaction works, he should have wait for the right number of confirmation before he send the product, every coin has a required number of transactions and he should be aware of that.

it is a tough call that someone will accept BTC without even knowing how the network is functioning, but you should never blame the victim

someone tried to allow BTC payments, and after scam like this one, he will probably give up on BTC payment, which is not a good thing for a mass adoption, and one should always show empathy to the victim, and not blame one to have not being too serious to read all the small letters included

[erikoy]

It can give so much time to make a transaction again to cancel the previous transaction because the btc nodes confirm the latest transaction usually in 10 minutes and that will give ample time for the scammer to make a new transactions and to cancel the previous one.

As what had been mention by other users that the first transaction being made was being rejected. And remove from the network. Scammers really are brilliant in taking advantage of this kind of processmof bitcoin transaction. So we must all be careful instead not getting trick or outsmart by the scammers.

[sujonali1819]

This also happened to me in the past. I agreed to sell an altcoin to a stranger in telegram. I was agreed because The guy wanted to pay BTC to me fast. And I will pay him later. That time I follow him as clever because without any reason no stranger can agree to pay fast without debating a ward. He sent me Bitcoin to my address and ask for the altcoin from me. I said to him to wait for at least one confirmation. But the guy blaming again and again that this is not like a business, he have to sell the altcoin, the market going down bla bla bla, I was strong since I have already got the bitcoin to my wallet , and saying him I can not send it before any confirmation. one, two, six hours even 1 days gone but the tnx is pending. after 1 more day maybe the tnx gone from tnx history.

[Findingnemo]

Check this thread- https://bitcointalk.org/index.php?topic=5279758.0
OP has been scammed because they accepted tx without a single confirmation. It's possible to manipulate a tx in such cases where scammer will send you the fund and make sure they have received what they have paid for and later they will create another tx with higher fee with the same input. The later tx will get confirmed and yours one will be invalid.
Therefore, don't accept zero confirmation tx. Wait for at least 1 confirmation.

Based on that story OP is a seller and he accepts Cryptocurrency for payment to his product, he is a newbie seller and naive, he should know how transaction works, he should have wait for the right number of confirmation before he send the product, every coin has a required number of transactions and he should be aware of that.

it is a tough call that someone will accept BTC without even knowing how the network is functioning, but you should never blame the victim

someone tried to allow BTC payments, and after scam like this one, he will probably give up on BTC payment, which is not a good thing for a mass adoption, and one should always show empathy to the victim, and not blame one to have not being too serious to read all the small letters included

But someone is ignorant about the crypto payments they should get the knowledge first before receiving the funds, maybe he lost the money but it is a good lesson and will keep him aware of this forever and also he might teach other people about which mistakes should be avoided to save ourselves from scams.