BitUndo.com - Anyone tried this?

[Stedsm]

Hey guys,
I have seen this in some thread and would like to know whether someone tried this one?
If yes, were the results fine and accurate as mentioned? I mean do you actually get your Bitcoins back?
Any test transactions done? If so, what were the results?

[waterpile]

Hey guys,
I have seen this in some thread and would like to know whether someone tried this one?
If yes, were the results fine and accurate as mentioned? I mean do you actually get your Bitcoins back?
Any test transactions done? If so, what were the results?

Bitundo makes it quite clear that there is no guarantee, and they make no promise to get your payment back.

https://www.cryptocoinsnews.com/undoing-undoable-bitundo-doublespending-bitcoins-service/

[Stedsm]

Bitundo makes it quite clear that there is no guarantee, and they make no promise to get your payment back.

https://www.cryptocoinsnews.com/undoing-undoable-bitundo-doublespending-bitcoins-service/

Not about the guarantee, but what's their purpose of doing this, and how can one benefit if they are actually not able to provide what they are talking about?

[Bitcoin Explorer]

Even I am interested in knowing whether this actually works. To be honest, it better not work as it can play the role of a chargeback :p
Anyway, I saw a thread yesterday in which some guy was trying to get his money back which was stolen by a hacker, and the victim was offering 1 BTC bounty and someone suggested bitundo

[SebastianJu]

Im wondering too since there are payment services out there, like bitpay that accept payments with zero confirmations. I wonder how they would handle if such a transaction would be cancelled.

I imagine it can work as long as the miner, who gets two transactions for the same coins, takes the transaction with the higher fee. But i dont know if miners have a routine for that at all.

So i would be interested to know if it works too. Though they seem confident about it.

[Lorenzo]

Im wondering too since there are payment services out there, like bitpay that accept payments with zero confirmations. I wonder how they would handle if such a transaction would be cancelled.

I imagine it can work as long as the miner, who gets two transactions for the same coins, takes the transaction with the higher fee. But i dont know if miners have a routine for that at all.

So i would be interested to know if it works too. Though they seem confident about it.

What BitUndo advertises is something called a "race attack":

http://en.bitcoin.it/wiki/Double-spending#Race_attack

Most pools use the standard reference client which accepts the first transaction received rather than the one with the highest fee. What BitUndo does differently is it chooses the one with the higher fee instead. Someone who wishes to execute a double spend attempt can push two transactions at the same time with one transaction having a higher fee than the other. If the next block is mined by BitUndo, the transaction with the lower fee is then invalidated and never included in the blockchain.

The chances of this attack succeeding depends on whether or not the next block is mined by BinUndo. If BitUndo's pool becomes more popular, then it's likely that businesses which accept zero confirmation transactions will have to change their practices. I'm not sure if it's already done but gambling sites, for example, might only honor withdrawals after the initial deposits have been confirmed. Fortunately, BitUndo is a tiny pool with a tiny hashrate and is therefore responsible for a tiny percentage of total blocks mined so the risk for businesses is still quite small.

[Muhammed Zakir]

I tried once but I couln't sign the raw transaction they gave.

Im wondering too since there are payment services out there, like bitpay that accept payments with zero confirmations. I wonder how they would handle if such a transaction would be cancelled.

I imagine it can work as long as the miner, who gets two transactions for the same coins, takes the transaction with the higher fee. But i dont know if miners have a routine for that at all.

So i would be interested to know if it works too. Though they seem confident about it.

BitUndo has their own pool and they choose these transactions when they mine. We can point miners to their pool.

[jdebunt]

Not the kind of service I would try to be honest, without a guarantee of getting funds back...no ty

[Muhammed Zakir]

Not the kind of service I would try to be honest, without a guarantee of getting funds back...no ty

You are obviously mistaken. They don't take our funds away. They tell us to input TXID in which we want to change 1 or more outputs. After we proceed, they ask us which output should be removed and where to send it. We can either choose one of the output address or can use new address. They will add an address in which their fee* is sent in that newly created transaction. It will be unsigned raw transaction and we will need to sign it. After we sign, we will submit signed raw transaction in their website. They mine and add all transaction we submit in their website. If you are lucky, they finds block and double-spend gets confirmed. If you are too lucky, any other pool which finds block may have added it.

* Fee depends on the output amount of the output you want to undo.

[SebastianJu]

Im wondering too since there are payment services out there, like bitpay that accept payments with zero confirmations. I wonder how they would handle if such a transaction would be cancelled.

I imagine it can work as long as the miner, who gets two transactions for the same coins, takes the transaction with the higher fee. But i dont know if miners have a routine for that at all.

So i would be interested to know if it works too. Though they seem confident about it.

What BitUndo advertises is something called a "race attack":

http://en.bitcoin.it/wiki/Double-spending#Race_attack

Most pools use the standard reference client which accepts the first transaction received rather than the one with the highest fee. What BitUndo does differently is it chooses the one with the higher fee instead. Someone who wishes to execute a double spend attempt can push two transactions at the same time with one transaction having a higher fee than the other. If the next block is mined by BitUndo, the transaction with the lower fee is then invalidated and never included in the blockchain.

The chances of this attack succeeding depends on whether or not the next block is mined by BinUndo. If BitUndo's pool becomes more popular, then it's likely that businesses which accept zero confirmation transactions will have to change their practices. I'm not sure if it's already done but gambling sites, for example, might only honor withdrawals after the initial deposits have been confirmed. Fortunately, BitUndo is a tiny pool with a tiny hashrate and is therefore responsible for a tiny percentage of total blocks mined so the risk for businesses is still quite small.

Thanks for explaining. Sounds like its not really a thread yet. Though even if they reach some percent of the network they could become a threat. A small chance is still more than nothing. But even then... the services with zero confirmation acceptance arent many. And most products arent delivered instantly so that the business owner could intervent.

Interesting thing... i wonder if we will hear something about it again.