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BitUndo – Double Spending as a service

bitundo.com

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Re: BitUndo – Double Spending as a service

#2
Wild. So, if this takes off (ie, enjoys miner adoption) and if the incentive structure works as advertised (ie, miners stand to make more by accepting the invalidating transactions), then this pretty much destroys the credibility of 0-confirms except with trusted parties, yes?

Re: BitUndo – Double Spending as a service

#3
post #2

Wild. So, if this takes off (ie, enjoys miner adoption) and if the incentive structure works as advertised (ie, miners stand to make more by accepting the invalidating transactions), then this pretty much destroys the credibility of 0-confirms except with trusted parties, yes?

There never was any credibility behind an unconfirmed transaction.

Re: BitUndo – Double Spending as a service

#4
post #2

Wild. So, if this takes off (ie, enjoys miner adoption) and if the incentive structure works as advertised (ie, miners stand to make more by accepting the invalidating transactions), then this pretty much destroys the credibility of 0-confirms except with trusted parties, yes?

Zero-confirm transactions have zero credibility anyway, so nothing lost here...

Re: BitUndo – Double Spending as a service

#5
So, in practice, what is the probability that a transaction would really be cancelled if the issuer of the payment uses this service approximately two minutes after initiating the transaction? (I assume that two minutes are a realistic estimate of the time it takes to realise that one has made a mistake, remember this service, search for it online, and fill out the necessary info.)

Re: BitUndo – Double Spending as a service

#6
post #5

So, in practice, what is the probability that a transaction would really be cancelled if the issuer of the payment uses this service approximately two minutes after initiating the transaction? (I assume that two minutes are a realistic estimate of the time it takes to realise that one has made a mistake, remember this service, search for it online, and fill out the necessary info.)

There's too many variables to give a simple answer. It depends on the current state of the network (the miners mempools), the priority of your transaction, the fee/bytes of your transaction, and what % of the hashing power bitundo has. Some transactions take a few blocks to get confirmed, these are the ones that have a much, much higher likelyhood of being undone.

Re: BitUndo – Double Spending as a service

#7
Interesting product. It doesn't really look like this is meant to make any money for the developer yet (maybe the plan is to add fees to their mining pool at some point in the future?). I suspect the point is to drive policy so that companies and individuals don't trust transactions with zero confirmations, or at least start checking for double-spend attempts. The standard right now for many companies is to accept zero-confirmation transactions (e.g. bitpay does this). Because this is such a widespread practice, it's effectively a security vulnerability of the bitcoin network as a whole. If this site can change this standard, then maybe they'll make the bitcoin ecosystem more secure.

This is an interesting phenomenon of the bitcoin ecosystem. If someone owns a lot of bitcoins, they're incentivized to make something like this even if it doesn't directly make them any money.

By the way, the extended FAQ for the mining pool is still showing Lorem Ipsum text: http://www.bitundo.com/pool/faq.html

Re: BitUndo – Double Spending as a service

#8
I think people should stick to n-of-m checking versus this scheme.

When people try to undermine a system, two negative things may happen: 1) The system that is being undermined will be pushed too far and it won't be see as reliable and/or 2) The system that is perpetrating the undermining will get patched out of existence.

Both scenarios end poorly for the bitcoin ecosystem.

If you want to send a bitcoin but aren't sure you'll be receiving what was intended to be your half of the transaction, stick to n-of-m signature transactions.

https://en.bitcoin.it/wiki/Contracts

EDIT: With that being said, I believe it's time for the BTC community to figure out how to patch this problem before it ruins zero-confirm for bitcoin.

Re: BitUndo – Double Spending as a service

#9
post #3
post #2

Wild. So, if this takes off (ie, enjoys miner adoption) and if the incentive structure works as advertised (ie, miners stand to make more by accepting the invalidating transactions), then this pretty much destroys the credibility of 0-confirms except with trusted parties, yes?

There never was any credibility behind an unconfirmed transaction.

You can't pretend like zero-confirmation transactions have never been useful. They have been used in practice for small amounts, many times, with no issues, and this system obviously changes things.

Re: BitUndo – Double Spending as a service

#10
post #5

So, in practice, what is the probability that a transaction would really be cancelled if the issuer of the payment uses this service approximately two minutes after initiating the transaction? (I assume that two minutes are a realistic estimate of the time it takes to realise that one has made a mistake, remember this service, search for it online, and fill out the necessary info.)

>Q: How likely is it to undo my transaction A: The likelihood is approximately the same as the percentage of mines using bitundo. Right now, this is pretty low.

If I understand correctly, the time left doesn't really matter. It should be totally dependent on their share of hashing. If undoing requires them to pick the winning nonce, it should be much like a lottery (your chance at any given time depends more on your share of purchased tickets more than anything else).

And if that's the case, this seems like a pretty pointless service. Until they get a large share, it won't work the vast majority of the time. And even when they do get a large share, undoing still won't work most times.

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