Sorry guys but i didn't get how works the 6 confirmation
if i send 0.1 btc with low fee and then 0.1btc with high fee , the first transaction will stay unconfirmed after 6 block anyway because of the low fee ?
also if send the money to an exchange why the exchange does not wait the transactions to come through instead of 6 block?
very confusing for me
The more fees you put into a txid it will gets confirmed first, normally if you sent thru an exchange it has a fee for sending and it would be sent with a higher fee because sending out from an exchange everyone pays an amount of fees and transactions will be SENT together as 1, correct me if im wrong.if i send 0.1 btc with low fee and then 0.1btc with high fee , the first transaction will stay unconfirmed after 6 block anyway because of the low fee ?
also if send the money to an exchange why the exchange does not wait the transactions to come through instead of 6 block?
very confusing for me
Depends on the wallet, different wallets have different processes to double spend (or don't allow you to). Double spending basically replaces a transaction that you have already made, by spending the same input multiple times (hence the term 'double spending'). Only one can get confirmed, so the others stay unconfirmed forever.
Let me know the txid and the wallet you use, and I can help you double spend with a higher fee so that it's confirmed.
So basically sending transaction out with low fees and after that sending it with higher fees with the same amount? Double spending is used by Scammers right? So how double spending does the scam? Normally sent out BTC doesn't allow you to cancel the transaction right?Let me know the txid and the wallet you use, and I can help you double spend with a higher fee so that it's confirmed.
I used BlockChain wallet to send out.
The txiid is there https://blockchain.info/tx/72c4eadfe654f79307936ec0a2de74c87e5e92414120227d3ce8e15962556ee6
I doubt that double spending sees much use by scammers nowadays, as it will only work with people who don't have a basic understanding of the bitcoin network/blockchain -- To them it might look like the transaction is incoming, while it actually is never going to confirm.
It is much more often used by people performing RBF - Replace-By-Fee, -- rebroadcasting their transaction with a higher fee, as Darkstar already stated.
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Normally sent out BTC doesn't allow you to cancel the transaction right?
No, but it doesn't prevent you from sending out these coins again with a higher fee to another adress, thus making them confirm faster while it looks like they're going to be received by another adress.
(Atleast that is the case with most wallets, eg electrum.)
