Topic: Can a transaction in a 6 block confirmation removed - page 2. (Read 391 times)

Whatever tx fee or fee rate attached to your tx goes to the miner, even if you estimated wrongly and overpaid, there is no such return, the fees is what miners use to decide the priority of transactions in the mempool, they can't decide if you willingly overpaid or not. In a tx what returns back to you is change, if there is any. If you are spending a particular utxo, but you are not spending all of it, one of the outputs returns to you as change. Tx fee is simply inputs - outputs, that is what finally goes to the miner.

Theoritically, it is possible if attackers have enough hashrates.
Practically, it is impossible because cost is high, nearky impossible to have such high dominating hashrate and benefit is not high

Use either two following tools to have estimating exercises.

• https://jlopp.github.io/bitcoin-confirmation-risk-calculator/
• https://web.archive.org/web/20181231045818/https://people.xiph.org/~greg/attack_success.html

In addition to what others have explained above; Just imagine you have 6 containers loaded with cars, that are all stacked at the top of each other and your car is stuck at the bottom of the first container, do you think it will be possible to get your car out the first container so easy, you will have to take down the first 5 containers before you can get to the last one, that is what the description is explaining, the more block is stack on top of each other, the less chances of it been reverse back.

With the current computational mining power of Bitcoin being distributed to different miners, the chances are low until you have more than about 51% of the power before that can happen. As long as you don't have that power or other miners ready to join hands with you, that is a mission impossible because once a transaction is confirmed, that is the final, it is good as dead living that no longer breathe, that block will remain sealed forever. However, if it's an overpaid fee in a transaction, perhaps you made a mistake during the course of a transaction, they may (low chances) return the fees to you for the error.

The correct term here is stale blocks. Orphaned blocks refer to blocks without a known parent (as the word "orphan" implies), which is something different.

Also, a transaction which is included in the losing chain will only go back to unconfirmed if it is in neither of the block at the same height or the block at height +1 in the winning chain. Otherwise it will remain confirmed despite the chain split.

No, it won't. Broadcasting an RBF replacement does not make the original transaction invalid whatsoever. The original transaction remains entirely valid and could still be included in a block if a miner chose to do so or did not learn about the higher fee paying replacement.

Your numbers are all wrong.

If you take the equations from section 11 of the whitepaper and plug in the numbers for an attacker with a probability of 0.5 of finding the next block (i.e. 50% of the hashrate), then the probability they will catch up from any deficit is 1.

You are assuming that both attacker and honest miners will mine blocks at a regular 10 minute interval. Given that there is random variance, and given an unlimited amount of time, then the attacker will in fact always catch up. With honest nodes simply following the chain with the most work, then honest miners have to stay ahead at all times, whereas the attacker only has to take the lead once for all honest nodes to then switch to their malicious chain.

Further, a 60% attack does not mean the attacker is 10% faster. If the attacker has 60% of the hashrate against an honest 40%, then the attacker is 50% faster than the rest of the network.
A 70% attack results in the attacker being 70/30 = 2.33 times faster, and an 80% attack results in the attacker being 80/20 = 4 times faster.

Again, not true. With 51% of the hashrate you are mathematically guaranteed to overtake any deficit. You certainly don't need 80%.

Not possible for the current transaction because Bump fee will be only available if its opted at the time of broadcasting since you mentioned it is not supported on Trust wallet then there is no way to do that even if the user import into electrum or any other wallet. In that case Child pays for parent (CPFP) is the only choice to increase the fee from the receiving end which is also not possible in this case here cause it is going into Binance wallet.

First of all don't use trust wallet anymore cause its closed source and don't try to import the seeds into any other open source wallet too, so the best thing to do is create a fresh wallet and move the funds from trust wallet to another.

I suggest Unstoppable wallet as best alternative to trust wallet.

a few things to keep in mind

A mining pools make about 6.25btc a block meaning cost per block is ~$185k

next is that to go back 6 blocks means you have to re mine them blocks.
if a pool only matches the speed(50%) of the rest of the network it will never catch up and always be 6 blocks behind
EG

normal 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
attack  06 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

so to over take the normal network that just continued, you will need more then the normal network speed to catch up
EG 10% faster (60% attack)
normal 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
attack   06 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

EG 20% faster (70% attack)
normal 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
attack    06 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29


EG 30% faster (80% attack)
normal 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20
attack    06 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20


as you can see even after doing over 20 blocks costing millions of mining power you may only get to overtake within 20 blocks if you had like 80% of hashpower

this is why unless the pools has a large multi million dollar transaction it wants to maliciously reverse. and alot more then 50% of the network hashrate, its not worth them trying to go back so many confirms and then waste so many more blocks trying to play catch up to try to overtake the network to get their chain of edited block recognised as the chain the network should follow

It could be possible if the transaction is flagged as RBF, if a transaction is flagged it can be replaced with a new one where you pay a bigger amount of sats as transaction fee. But most of the nodes do have full RBF yet so you can check your transaction in mempool. If you see the RBF option in green color like the segwit in the picture then it is flagged RBF



I don’t think trustwallet support RBF just yet but is ok to import the seed into BlueWallet, it supports RBF and if you see the pending transaction then you can click the bump fee option and then increase the transaction fee. But if the transaction doesn’t have RBF flagged then you can double spend it by sending same amount of the bitcoin and then using a higher transaction fee than the first one initiated

Yes, you can import your wallet from trustwallet to electrum using your seedphrase and then bump the transaction using RBF to speed up confirmation.

Ideally you should sweep your coins from trustwallet to electrum and not just import it.

This does not make the former transaction invalid, the miner can still see both but will most likely choose the one that pays a higher transaction fee.

ViaBTC is a good Bitcoin accelerator and you don't give them any information about your wallet besides he txid.

Oh really!
Well I can say I did respond base on my experience so far but however, I have also added something positive to my wisdom bank and thank you for the clarification. I think is always good involving in deep discussion with those that I think are more than me. Please pardon me for that.

I did use Trustwallet to send out payment and not electrum wallet, is there a way or is it possible after importing wallet to Electrum and speeding up transaction?
Maybe I won't proceeding with it to ensure my transaction has been confirmed. Since on 14 I sent out about 62.5$ hasn't confirmed to my binance address.

Depends on how much the user send their coins, if they only send small amount Bitcoin e.g. less than 1 BTC you don't need to worry because it's high likely they will not do double spend because it's need a cost to double spend the transaction.

I think it's pointless to suggest someone to not do double spend because it's unethical or dishonest because you wouldn't know what they will do in the real life.

I'd not call it not advisable, just that you should not rely on them. They can help if things go wrong, but they are not a magic tool that will accelerate your transaction plus most of the time they have a limit on how many and which transactions to accelerate. Using RBF is going to be better IMO.

Transactions cannot be reversed but unconfirmed transactions can be double spent that's why it is important to be confirmed by at least three blocks. The sender can increase the transaction fees and also change the recipient of the funds which will make the former transaction invalid (Replace by Fee (RBF).

Some mining pools offer transaction acceleration services but is not advisable to use them because you will be relying on a third-party service provider. But you can try adopting RBF or CPFP. In Replaced by Fee the sender will have to pay a higher transaction fee to make the transaction more attractive to miners. While in Child pays for Parent it is the recipient that bears the cost of broadcasting a new transaction.

You should move this thread in Bitcoin Technical Support board. Blockchain is immutable. It's decentralized and there is no central power, that's why you can't alter the data that's stored in blocks. Imagine blockchain case like, you upload picture on your facebook and then people start to download it and upload on another websites. How can you get your picture permanently removed from the internet? Keep in mind that if you ask them, they never respond. Your only way is the network's consensus, so, the only way to remove transaction from blockchain can only be done with the network's consensus.
That's just what I know but there are people like o_e_l_e_o who definitely can give you a top-notch answer.

Electrum Wallet has an option called Cancel that cancels your transaction by making a double-spend. So, it's possible to cancel Bitcoin transaction if you use Electrum and if it is unconfirmed yet.

It is theoretically possible but rarely or never practical.
For majority of transactions it is unprofitable to even attempt to reverse it for a miner that had the means. So if you're sending something less than tens of millions of dollars, then less than six confirmations is enough for certainty.

If someone had unlimited computing power which no one has, it is possible to attempt, but considering it is unprofitable and it's not 100% guaranteed it will succeed, it's not worth it.

If it's on an electrum wallet you can use RBF to bump the transaction fee up. Since you're sending to finance using CPFP is not on the cards.

Possible, yes! Likely to happen, no!
There was a thread recently about it:
https://bitcointalksearch.org/topic/how-many-bitcoin-confirmations-is-enough-5443953


False! Unconfirmed transactions are not set in stone, it's not just about being reversed, it's about them not ever getting confirmed or being dropped out of the mempool after a while for being a low paying tx, that's the whole reason most exchanges or gambling sites wait for at least 1 to 3 blocks to confirm your deposit.
It's one thing to not be concerned when the one doing such tx is you between your wallets, a different story when accepting payments from a stranger.

This is never possible to get it reversed after 6 block confirmation..
Let say if a transaction is being sent immediate you can't reversed it because you had initiated the transaction, it may be pending for over hours but can't be reversed just I as do sent out btc since on 14 of August and it the transaction hasn't confirmed yet but looking from explorer (txt) I noticed the sender address is empty and while the receiver address has the balance inside of it but has not yet confirmed. I checked through my Binance app I couldn't see it but still pending transaction ( now it can only get to my binance app after the 6 block confirmation so this cause me not to panic anymore) but if there were ways for boosting the transaction I wouldn't mind proceed with it.

I mean in theory it is possible but you would need a lot of computing resources to do it. Which I think is not possible by a single entity because of its decentralized nature. In general 6 confirmation is considered for a transaction to be irreversible as major exchanges and big merchants atleast consider 4 confirmation to consider a transaction to be final.

Transactions with at least two to six confirmations are seemingly impossible to reverse because of the number of blocks built on them. The transaction with just one block confirmations is what bitcoiners believe is reversible because of the cases of the block in which the transaction is been orphaned. Orphaned blocks occurs when two blocks are sent simultaneously to nodes and as miners mined or build blocks the longest chain one is been picked by the nodes and the later dropped back to the mempool. So if your transaction happens to be in the short chain then it can be reversed.

So seeing this means it can only occur to transactions in the top top blocks. A 5 blocks downward transaction can not be orphaned and there cannot be reversed. So 6 block confirmation can not be reversed

I've been curious to wanting to know the possibility  to reversing or removing a sent transaction on a block which has already passed 6 block confirmation and after reading a post from a free signature space of a user which I can't remember which reads "Each block is stacked on top of the previous one. Adding another block to the top makes all lower blocks more difficult to remove: there is more "weight" above each block. A transaction in a block 6 blocks deep (6 confirmations) will be very difficult to remove.
Judging from this, the writings stated that it is difficult  and not impossible and I've been wanting to know if will be possible to reverse a transaction after a 6 block confirmation?