Topic: can you reverse or cancel a bitcoin transaction? - page 5. (Read 1182 times)
It is trivial to do before the first confirmation. You'll require hundreds of millions in mining equipment after the first one. This is not how bitcoin used to work a few years ago so a lot of merchants get scammed.
you can reverse bitcoin transactions made by your own wallet with https://dcryptex.com
you can reverse bitcoin transactions made by your own wallet with https://dcryptex.com
I visited this site and quickly scanned the explanation they gave on how they cancel transactions, and all i can say is: that's not how this works... As soon as a transaction is confirmed, it's allmost impossible to cancel the transaction unless you own enough asic's to do a 51% attack... Any site claiming otherwise are a potential scam
After one block confirmation it becomes impossible to reverse, that is why before to carry out a transaction it's best you be 100% sure of the address and other necessities, many have unknowingly sent bitcoins to the wrong address or to a scammer, manual checking is also necessary sometimes
bitcoin transaction that we have done will not be canceled, this is the system that I think is very good from bitcoin after we do bitcoin transaction then we just wait for the results of the transaction
You don't need to worry about double spending. If you make a transaction using bitcoin there isn't anyway to cancel the request. Once it is made it is made. The only way to stop a transaction by double spending is if the transaction isn't confirmed. In the real world people wait until transactions are confirmed in order for it to mean anything.
--snip--
But is there someone who has been able (recently) to cancel a broadcasted transaction?
or is it definetely that there is NO WAY to cancel a transaction?
Thus it makes sense to discuss it again.
But is there someone who has been able (recently) to cancel a broadcasted transaction?
or is it definetely that there is NO WAY to cancel a transaction?
Thus it makes sense to discuss it again.
I have a habit of cheaping out on fees when i move funds between my own wallets. Nowadays, i always opt-in RBF, which makes it very easy to create a double spending transaction with a higher fee and broadcast it, but about a year ago, i did have to create new transactions doublespending the unspent outputs used and input of my own transactions several times. It was during the spam attack and the astronomical fees, and before opt-in RBF was adopted in my wallet, so many of my low-fee between-my-own-wallet transactions got "stuck". doublespending was the fasted way of fixing these problems.
It can be done, but like i said: if you wait for 1+ confirmations, the transaction can no longer be "cancelled" this way.
Very clear! Thanks!
If the transaction is confirmed already then you cannot undone it. But otherwise I read some tricks that will make some adjustments while the transaction isn't confirmed yet. I found it in the first page of this this thread but I didn't verify since you need to do it accordingly.
--snip--
But is there someone who has been able (recently) to cancel a broadcasted transaction?
or is it definetely that there is NO WAY to cancel a transaction?
Thus it makes sense to discuss it again.
But is there someone who has been able (recently) to cancel a broadcasted transaction?
or is it definetely that there is NO WAY to cancel a transaction?
Thus it makes sense to discuss it again.
I have a habit of cheaping out on fees when i move funds between my own wallets. Nowadays, i always opt-in RBF, which makes it very easy to create a double spending transaction with a higher fee and broadcast it, but about a year ago, i did have to create new transactions doublespending the unspent outputs used and input of my own transactions several times. It was during the spam attack and the astronomical fees, and before opt-in RBF was adopted in my wallet, so many of my low-fee between-my-own-wallet transactions got "stuck". doublespending was the fasted way of fixing these problems.
It can be done, but like i said: if you wait for 1+ confirmations, the transaction can no longer be "cancelled" this way.
I actually like your idea about double spending, now back to the topic, i guess there is no way it is reversable, that is why you need to check it multiple times before making a transaction. There are also notifications that tells each user that it cannot be reversed, so you have to be aware, once it is confirmed, there is no turning back, and no regrets when it is done.
--snip--
But is there someone who has been able (recently) to cancel a broadcasted transaction?
or is it definetely that there is NO WAY to cancel a transaction?
Thus it makes sense to discuss it again.
But is there someone who has been able (recently) to cancel a broadcasted transaction?
or is it definetely that there is NO WAY to cancel a transaction?
Thus it makes sense to discuss it again.
I have a habit of cheaping out on fees when i move funds between my own wallets. Nowadays, i always opt-in RBF, which makes it very easy to create a double spending transaction with a higher fee and broadcast it, but about a year ago, i did have to create new transactions doublespending the unspent outputs used and input of my own transactions several times. It was during the spam attack and the astronomical fees, and before opt-in RBF was adopted in my wallet, so many of my low-fee between-my-own-wallet transactions got "stuck". doublespending was the fasted way of fixing these problems.
It can be done, but like i said: if you wait for 1+ confirmations, the transaction can no longer be "cancelled" this way.
It has been said sometimes that a Bitcoin transaction can be cancelled or reversed using for example double-spend.
Is it still possible? If Yes, how? If No, Why?
Especially when you sell services and goods and accept Bitcoin payment, you are worried about this.
So it should be a good idea to discuss this topic.
Is it still possible? If Yes, how? If No, Why?
Especially when you sell services and goods and accept Bitcoin payment, you are worried about this.
So it should be a good idea to discuss this topic.
You can't cancel or revert a transaction.
However, there are a couple "tricks" you can pull while a transaction is UNCONFIRMED.
For example, you can create a (very) low-fee transaction, and broadcast it to as little nodes as humanly possible. Then, create a new transaction, using the same unspent outputs as input but funding a completely different address as the first transaction. You can create this secondary transaction with a much higher fee and broadcast it to as many nodes as possible.
If you do this, there is a decent chance a miner will put the second transaction into the block he's currently working on instead of the first one. And once one of those transactions ends up in a valid, broadcasted block that's been added to the blockchain, the other transaction is automatically "voided". It's using unspent outputs that are no longer in the UTXO set, so the unconfirmed tx becomes invalid.
If you're setting up a service, it's always a good idear to wait for at least 1 confirmation before sending goods or services. For expensive products, you might even chose to wait 3+ confirmations ( 6+ for the really paranoid shop owners). Once a transaction has a couple of confirmations, there is no way of cancelling or reversing it.
Thanks for the advice.
It has been said sometimes that a Bitcoin transaction can be cancelled or reversed using for example double-spend.
Is it still possible? If Yes, how? If No, Why?
Is it still possible? If Yes, how? If No, Why?
An already confirmed transaction that has been included in a block can't be cancelled.
So it should be a good idea to discuss this topic.
It is a better idea to search before starting a new thread:
https://bitcointalksearch.org/topic/cancel-my-unconfirmed-transactions-bounty-1922415
https://bitcointalksearch.org/topic/cancel-unconfirmed-transaction-1901899
https://bitcointalksearch.org/topic/any-way-to-cancel-an-unconfirmed-transaction-1238034
https://bitcointalksearch.org/topic/cancelling-unconfirmed-transactions-151430
https://bitcointalksearch.org/topic/cancel-unconfirmedstuck-transactions-1742325
https://bitcointalksearch.org/topic/cancel-transaction-that-is-in-process-1177722
https://bitcointalksearch.org/topic/how-to-cancel-transaction-1516140
https://bitcointalksearch.org/topic/how-to-cancel-a-transaction-1012583
Of course, a search is always helpful. I agree with you!
However, these threads are outdated, and in some of them, it has not been clearly answered.
The technology is moving forward and we need to know what is the actual stand.
I've read about double spending and found this for example
Quote
It is when a person broadcast two seperate transactions which spends the same outputs. Since the majority of the network runs Bitcoin Core, the reference client, they would first receive the first transaction and store it in their mempool. The other transaction will then be rejected. It is fairly hard to attempt to doublespend the transaction on the blockchain but it can be accomplished. If you have a transaction which has low fees, wait till most of the peers drops your transaction in the mempool then you can broadcast it again. Blockchain.info used to have a page to allow people to test it out but it's removed already. There are also some open sourced programs that allows you to double spend but I can't guarantee it is safe since you have to give your private key.
Blockchain.info seems to be rebroadcasting your transaction whenever it gets dropped out of mempool. Get the private key and delete it out from your blockchain.info, store it somewhere safe then wait for a week. After that, verify that it has dropped out of the mempool and import it to a desktop client to send the BTC. That's what I have done before anyway.
Blockchain.info seems to be rebroadcasting your transaction whenever it gets dropped out of mempool. Get the private key and delete it out from your blockchain.info, store it somewhere safe then wait for a week. After that, verify that it has dropped out of the mempool and import it to a desktop client to send the BTC. That's what I have done before anyway.
But is there someone who has been able (recently) to cancel a broadcasted transaction?
or is it definetely that there is NO WAY to cancel a transaction?
Thus it makes sense to discuss it again.
It has been said sometimes that a Bitcoin transaction can be cancelled or reversed using for example double-spend.
Is it still possible? If Yes, how? If No, Why?
Is it still possible? If Yes, how? If No, Why?
An already confirmed transaction that has been included in a block can't be cancelled.
So it should be a good idea to discuss this topic.
It is a better idea to search before starting a new thread:
https://bitcointalksearch.org/topic/cancel-my-unconfirmed-transactions-bounty-1922415
https://bitcointalksearch.org/topic/cancel-unconfirmed-transaction-1901899
https://bitcointalksearch.org/topic/any-way-to-cancel-an-unconfirmed-transaction-1238034
https://bitcointalksearch.org/topic/cancelling-unconfirmed-transactions-151430
https://bitcointalksearch.org/topic/cancel-unconfirmedstuck-transactions-1742325
https://bitcointalksearch.org/topic/cancel-transaction-that-is-in-process-1177722
https://bitcointalksearch.org/topic/how-to-cancel-transaction-1516140
https://bitcointalksearch.org/topic/how-to-cancel-a-transaction-1012583
It has been said sometimes that a Bitcoin transaction can be cancelled or reversed using for example double-spend.
Is it still possible? If Yes, how? If No, Why?
Especially when you sell services and goods and accept Bitcoin payment, you are worried about this.
So it should be a good idea to discuss this topic.
Is it still possible? If Yes, how? If No, Why?
Especially when you sell services and goods and accept Bitcoin payment, you are worried about this.
So it should be a good idea to discuss this topic.
You can't cancel or revert a transaction.
However, there are a couple "tricks" you can pull while a transaction is UNCONFIRMED.
For example, you can create a (very) low-fee transaction, and broadcast it to as little nodes as humanly possible. Then, create a new transaction, using the same unspent outputs as input but funding a completely different address as the first transaction. You can create this secondary transaction with a much higher fee and broadcast it to as many nodes as possible.
If you do this, there is a decent chance a miner will put the second transaction into the block he's currently working on instead of the first one. And once one of those transactions ends up in a valid, broadcasted block that's been added to the blockchain, the other transaction is automatically "voided". It's using unspent outputs that are no longer in the UTXO set, so the unconfirmed tx becomes invalid.
If you're setting up a service, it's always a good idear to wait for at least 1 confirmation before sending goods or services. For expensive products, you might even chose to wait 3+ confirmations ( 6+ for the really paranoid shop owners). Once a transaction has a couple of confirmations, there is no way of cancelling or reversing it.
It has been said sometimes that a Bitcoin transaction can be cancelled or reversed using for example double-spend.
Is it still possible? If Yes, how? If No, Why?
Especially when you sell services and goods and accept Bitcoin payment, you are worried about this.
So it should be a good idea to discuss this topic.
Is it still possible? If Yes, how? If No, Why?
Especially when you sell services and goods and accept Bitcoin payment, you are worried about this.
So it should be a good idea to discuss this topic.
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