$10k double spend... | Bitcointalksearch.org

Nemesis

sr. member

Activity: 462

Merit: 250

Quote from: Gabi on March 13, 2013, 02:20:12 PM

This is not what happened, the transaction of this double spend was put in a block in the 0.8 chain but not in the 0.7 chain. Once the rollback happened and miners started mining on the 0.7 chain they did not add the transaction, wich was then "double spended"

You didnt understand it right,

The transaction that is on .8 blockchain and doubled spend on pre .8 will be invalidated.

Other transactions will be added to pre .8 blockchains automatically. Its not lost (which what rollback means). Its still catching up with all the new blocks being mined right now.

Rollback means every transaction in .8 blockchain got cancelled.

Ps. i think you're confused the rollback as in downgrading the software to .7 , with what you said.

To understand clearly again what happened, i will sum up like this: This scenario isnt exactly similar to a 51% attack where one of the forks is completely invalidated. Instead the fork was "merged", even the blocks in .8 blockchains got orphaned, their transactions are still recorded and put into new blocks mining now. This gave an opportunity of a double spend as in RACE attack. The transactions in .8 blockchain goes back to 0 confirmation stage. Thats how this particular double spend happened. (his second spend became the first that got confirmed, his first spend is now invalidated as ..."double spend" )

Gabi

legendary

Activity: 1148

Merit: 1008

If you want to walk on water, get out of the boat

This is not what happened, the transaction of this double spend was put in a block in the 0.8 chain but not in the 0.7 chain. Once the rollback happened and miners started mining on the 0.7 chain they did not add the transaction, wich was then "double spended"

Nemesis

sr. member

Activity: 462

Merit: 250

Quote from: Gabi on March 13, 2013, 02:08:49 PM

Well this is what happen with a rollback, if you invalid the last ten blocks or so and do a rollback, it is normal that these transactions risk to be doublespended, since usually no one expect a transaction with over ten confirmations to disappear.

Rollback is technically incorrect. The transactions in .8 blockchine still gets merged to pre .8 blockchain.

Gabi

legendary

Activity: 1148

Merit: 1008

If you want to walk on water, get out of the boat

Well this is what happen with a rollback, if you invalid the last ten blocks or so and do a rollback, it is normal that these transactions risk to be doublespended, since usually no one expect a transaction with over ten confirmations to disappear.

chiropteran

sr. member

Activity: 348

Merit: 250

Quote from: Nemesis on March 13, 2013, 01:42:38 PM

A hard fork like this has caused the whole btc economy on hold. Potentially MANY transactions can be doublespended. If BTC had gone mainstream, it would have been $1millions lost in doublespending.

who cares?

One million, are you joking? That isn't even enough to care about.

http://www.verifi.com/news/press-releases-and-announcements/bid/142830/Special-Report-Feds-Bust-200-Million-Credit-Card-Fraud-Ring

One credit card fraud ring scammed over $200 million. And they didn't need the cooperation of 51% of the credit card processors to do this.

I guess if you are a merchant losing 200 million in credit card fraud is better than losing $10k from a once in a lifetime bitcoin fork, eh? Nice logic you have there, you must be some kind of business genius. Did you go to Harvard?

Edit: nevermind, don't bother answering. After looking at your other posts you are just an obvious troll, welcome to the ignore list.

Nemesis

sr. member

Activity: 462

Merit: 250

Quote from: molecular on March 13, 2013, 01:54:50 PM

Quote from: Nemesis on March 13, 2013, 01:42:38 PM

I wonder how these dumbasses survive life on daily basis.

A hard fork like this has caused the whole btc economy on hold. Potentially MANY transactions can be doublespended. If BTC had gone mainstream, it would have been $1millions lost in doublespending.

But double-spending doesn't lose any money. In fact, it doubles money, hence the name. It's all good!

Here a coin,
there a coin,
everywhere a coin coin.

Hahha

it sure does

molecular

donator

Activity: 2772

Merit: 1019

Quote from: Nemesis on March 13, 2013, 01:42:38 PM

I wonder how these dumbasses survive life on daily basis.

A hard fork like this has caused the whole btc economy on hold. Potentially MANY transactions can be doublespended. If BTC had gone mainstream, it would have been $1millions lost in doublespending.

But double-spending doesn't lose any money. In fact, it doubles money, hence the name. It's all good!

Here a coin,
there a coin,
everywhere a coin coin.

HighInBC

member

Activity: 85

Merit: 10

Quote from: johnyj on March 13, 2013, 05:17:26 AM

To be honest, fork is really a headache for bitcoin. In fiat world, you can never spend the same dollar on two different transaction network, since there is a central authority keep a book of everyone's account, and cash is physical (counterfeit cash is possible). But fiat money have other problem like generate dollar out of thin air, the effect is the same as double/triple/multiple spend, but only FED have the right to do it Wink

You can write a cheque that uses the same money twice, it will take weeks for them to figure it out. Credit cards get charged back all the time and merchants still accept those.

A successful double spend is like a bigfoot, often talked about and rarely seen.

I doubt merchants will consider this a significant issue.

Nemesis

sr. member

Activity: 462

Merit: 250

Quote from: bb113 on March 13, 2013, 09:28:20 AM

Quote from: chiropteran on March 13, 2013, 09:03:45 AM

Quote from: johnyj on March 13, 2013, 05:17:26 AM

To be honest, fork is really a headache for bitcoin. In fiat world, you can never spend the same dollar on two different transaction network, since there is a central authority keep a book of everyone's account, and cash is physical (counterfeit cash is possible). But fiat money have other problem like generate dollar out of thin air, the effect is the same as double/triple/multiple spend, but only FED have the right to do it Wink

In fiat world, nearly every real business accepts credit cards. Credit card charge-backs are the exact same effect for the merchant as a double-spend, but much easier to produce for the scammer.

Quote from: Nemesis on March 13, 2013, 12:13:41 AM

Son get real..... they're not gonna sue your ass for a shitty Rosewill parts that you bought.

If they don't care about losing money to a credit card charge back scam they won't care about losing money to a bitcoin double-spend that IS ONLY POSSIBLE because all the major mining nodes went along with it. Any idiot kid can try to do a charge back, double spending is impossible for any singular criminal or even a huge criminal organization unless they have control over 51% or more of the hashing power.

Quote from: Nemesis on March 13, 2013, 12:13:41 AM

The fact that you compare legitimated chargeback with double spend tell how smart you are.
What risk did Newegg take again?

You are the one crying and whining about a single double spend after 3 years of operation, that is only enabled because every major mining node agreed to fix the blockchain. As opposed to charge backs, which can occur all the time, and cost merchants a ton of money. If the double spend is a risk, charge backs are. If charge backs are not a risk, then neither is a double spend. They are the same thing.

Also, get a clue: legitimate or scam charge backs work the exact same way. It's not like a legitimate charge back doesn't cost the merchant time and money.

I agree the double spend was not a huge deal and there are easy ways for merchants to protect themselves from this type of thing, but disagree its the same as a chargeback. The rate of chargebacks is probably somewhat predictable, while these types of events could lead to a sudden, unexpected surge in chargebacks which can be much more dangerous.

I wonder how these dumbasses survive life on daily basis.

A hard fork like this has caused the whole btc economy on hold. Potentially MANY transactions can be doublespended. If BTC had gone mainstream, it would have been $1millions lost in doublespending.

Nemesis

sr. member

Activity: 462

Merit: 250

Quote from: johnyj on March 13, 2013, 04:19:05 AM

Quote from: Nemesis on March 13, 2013, 02:38:37 AM

Quote from: johnyj on March 13, 2013, 02:32:49 AM

It is NOT a double spend. It's spend the same coin twice on each different chain, once per chain, when there is a hard fork. And you can do it anytime when you make your own client and fork the main block chain

This is always a consequence of a hard fork, so a hard fork will cause many confusing things and it must be treated very careful

Wow the level of stupidity in this thread is thro the roof!

Do you even hear yourself pumpkin? "It is NOT a double spend. Its a spend the same coin twice"

A fascinating brain you got there.

Double spend means you spend your coins TWICE! Stupid.....

It doesnt matter which attack/venture it use (Race, Finney, Vector76, Brute-force, or >50% )

Pick one....

Maybe my word is not very clear, a Double Spend by definition is spend the same coin twice on the SAME NETWORK. After a hard fork, there are two networks, so the same pre-fork coins can be spent on each network. If you fork 3 chain, then you have 3 network, you can triple spend, and so on... that has nothing to do with each network's security. The problem is that merchant might not be aware of this situation

Hey there stupid,

what is a >50% attack again?

Did you even bother looking to it? Its an attack that allow double spending .... guess how? Because it creates a hard fork!

Stupid as stupid does.

Edit: btw, read this thread idiot: https://bitcointalksearch.org/topic/at-no-point-was-there-a-double-spend-in-the-longest-chain-152621

bb113

hero member

Activity: 728

Merit: 500

Quote from: chiropteran on March 13, 2013, 09:03:45 AM

Quote from: johnyj on March 13, 2013, 05:17:26 AM

To be honest, fork is really a headache for bitcoin. In fiat world, you can never spend the same dollar on two different transaction network, since there is a central authority keep a book of everyone's account, and cash is physical (counterfeit cash is possible). But fiat money have other problem like generate dollar out of thin air, the effect is the same as double/triple/multiple spend, but only FED have the right to do it Wink

In fiat world, nearly every real business accepts credit cards. Credit card charge-backs are the exact same effect for the merchant as a double-spend, but much easier to produce for the scammer.

Quote from: Nemesis on March 13, 2013, 12:13:41 AM

Son get real..... they're not gonna sue your ass for a shitty Rosewill parts that you bought.

If they don't care about losing money to a credit card charge back scam they won't care about losing money to a bitcoin double-spend that IS ONLY POSSIBLE because all the major mining nodes went along with it. Any idiot kid can try to do a charge back, double spending is impossible for any singular criminal or even a huge criminal organization unless they have control over 51% or more of the hashing power.

Quote from: Nemesis on March 13, 2013, 12:13:41 AM

The fact that you compare legitimated chargeback with double spend tell how smart you are.
What risk did Newegg take again?

You are the one crying and whining about a single double spend after 3 years of operation, that is only enabled because every major mining node agreed to fix the blockchain. As opposed to charge backs, which can occur all the time, and cost merchants a ton of money. If the double spend is a risk, charge backs are. If charge backs are not a risk, then neither is a double spend. They are the same thing.

Also, get a clue: legitimate or scam charge backs work the exact same way. It's not like a legitimate charge back doesn't cost the merchant time and money.

I agree the double spend was not a huge deal and there are easy ways for merchants to protect themselves from this type of thing, but disagree its the same as a chargeback. The rate of chargebacks is probably somewhat predictable, while these types of events could lead to a sudden, unexpected surge in chargebacks which can be much more dangerous.

chiropteran

sr. member

Activity: 348

Merit: 250

Quote from: johnyj on March 13, 2013, 05:17:26 AM

To be honest, fork is really a headache for bitcoin. In fiat world, you can never spend the same dollar on two different transaction network, since there is a central authority keep a book of everyone's account, and cash is physical (counterfeit cash is possible). But fiat money have other problem like generate dollar out of thin air, the effect is the same as double/triple/multiple spend, but only FED have the right to do it Wink

In fiat world, nearly every real business accepts credit cards. Credit card charge-backs are the exact same effect for the merchant as a double-spend, but much easier to produce for the scammer.

Quote from: Nemesis on March 13, 2013, 12:13:41 AM

Son get real..... they're not gonna sue your ass for a shitty Rosewill parts that you bought.

If they don't care about losing money to a credit card charge back scam they won't care about losing money to a bitcoin double-spend that IS ONLY POSSIBLE because all the major mining nodes went along with it. Any idiot kid can try to do a charge back, double spending is impossible for any singular criminal or even a huge criminal organization unless they have control over 51% or more of the hashing power.

Quote from: Nemesis on March 13, 2013, 12:13:41 AM

The fact that you compare legitimated chargeback with double spend tell how smart you are.
What risk did Newegg take again?

You are the one crying and whining about a single double spend after 3 years of operation, that is only enabled because every major mining node agreed to fix the blockchain. As opposed to charge backs, which can occur all the time, and cost merchants a ton of money. If the double spend is a risk, charge backs are. If charge backs are not a risk, then neither is a double spend. They are the same thing.

Also, get a clue: legitimate or scam charge backs work the exact same way. It's not like a legitimate charge back doesn't cost the merchant time and money.

johnyj

legendary

Activity: 1988

Merit: 1012

Beyond Imagination

To be honest, fork is really a headache for bitcoin. In fiat world, you can never spend the same dollar on two different transaction network, since there is a central authority keep a book of everyone's account, and cash is physical (counterfeit cash is possible). But fiat money have other problem like generate dollar out of thin air, the effect is the same as double/triple/multiple spend, but only FED have the right to do it Wink

glub0x

legendary

Activity: 892

Merit: 1013

i modified my client so that i created a hard fork, now i can spend my coins twice on 2 network. Am i double spending my bitcoins? not really

johnyj

legendary

Activity: 1988

Merit: 1012

Beyond Imagination

Quote from: Nemesis on March 13, 2013, 02:38:37 AM

Quote from: johnyj on March 13, 2013, 02:32:49 AM

It is NOT a double spend. It's spend the same coin twice on each different chain, once per chain, when there is a hard fork. And you can do it anytime when you make your own client and fork the main block chain

This is always a consequence of a hard fork, so a hard fork will cause many confusing things and it must be treated very careful

Wow the level of stupidity in this thread is thro the roof!

Do you even hear yourself pumpkin? "It is NOT a double spend. Its a spend the same coin twice"

A fascinating brain you got there.

Double spend means you spend your coins TWICE! Stupid.....

It doesnt matter which attack/venture it use (Race, Finney, Vector76, Brute-force, or >50% )

Pick one....

Maybe my word is not very clear, a Double Spend by definition is spend the same coin twice on the SAME NETWORK. After a hard fork, there are two networks, so the same pre-fork coins can be spent on each network. If you fork 3 chain, then you have 3 network, you can triple spend, and so on... that has nothing to do with each network's security. The problem is that merchant might not be aware of this situation

Nemesis

sr. member

Activity: 462

Merit: 250

Quote from: johnyj on March 13, 2013, 02:32:49 AM

It is NOT a double spend. It's spend the same coin twice on each different chain, once per chain, when there is a hard fork. And you can do it anytime when you make your own client and fork the main block chain

This is always a consequence of a hard fork, so a hard fork will cause many confusing things and it must be treated very careful

Wow the level of stupidity in this thread is thro the roof!

Do you even hear yourself pumpkin? "It is NOT a double spend. Its a spend the same coin twice"

A fascinating brain you got there.

Double spend means you spend your coins TWICE! Stupid.....

It doesnt matter which attack/venture it use (Race, Finney, Vector76, Brute-force, or >50% )

Pick one....

johnyj

legendary

Activity: 1988

Merit: 1012

Beyond Imagination

It is NOT a double spend. It's spend the same coin twice on each different chain, once per chain, when there is a hard fork. And you can do it anytime when you make your own client and fork the main block chain

This is always a consequence of a hard fork, so a hard fork will cause many confusing things and it must be treated very careful

Nemesis

sr. member

Activity: 462

Merit: 250

Quote from: willphase on March 13, 2013, 02:05:17 AM

this wasn't a double spend - it was a single spend on two different blockchains - I'm not sure why everyone is so concerned about this - the spend only existed once in the longest chain, it just happened that the longest chain changed, and it changed after 6+ confirmations had already happened in a previous longest chain. The issue here was that the merchant ignored or did not know about the advice to not accept confirmed blocks from the currently longest chain (the 0. Cool

because the 0.7 chain was going to outgrow it and invalidate those transactions.

At no point was there a double spend in the longest chain, which is exactly how bitcoin is designed to work.

Will

Noob, you dont understand what double spending is do you?

willphase

hero member

Activity: 767

Merit: 500

this wasn't a double spend - it was a single spend on two different blockchains - I'm not sure why everyone is so concerned about this - the spend only existed once in the longest chain, it just happened that the longest chain changed, and it changed after 6+ confirmations had already happened in a previous longest chain. The issue here was that the merchant ignored or did not know about the advice to not accept confirmed blocks from the currently longest chain (the 0. Cool

because the 0.7 chain was going to outgrow it and invalidate those transactions.

At no point was there a double spend in the longest chain, which is exactly how bitcoin is designed to work.

Will

zby

legendary

Activity: 1592

Merit: 1001

Quote from: Nemesis on March 12, 2013, 05:57:50 PM

...

The issue is not solved IMO. Simply orphan the fork and keep the default block size limit isnt a fix. We need to come up with a prevention system to put the whole thing in safe mode when this happens again.

...

That one is easy - merchants should look for forks - and then stop accepting payments. Sure there can be forks that are not visible for them - but this is taken into account in the design by waiting for the x amount of confirmations.

Topic: $10k double spend... (Read 4343 times)