$10k double spend... - page 3. | Bitcointalksearch.org

yokosan

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Quote from: Elwar on March 12, 2013, 01:59:19 PM

https://bitcointalksearch.org/topic/a-successful-double-spend-us10000-against-okpay-this-morning-152348

This is no hack of some Bitcoin service, this is a hit to Bitcoin itself.

How low will the price go once this gets out?

Once the merchant give up the price will drop.

humanitee

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Quote from: molecular on March 12, 2013, 03:48:11 PM

I don't understand how this double-spend even worked. Shouldn't his first tx have ended up in both chains in the first place? Why wasn't it included in the 0.7 chain?

It is my understanding that the .7 blockchain had imposed block size limits while the .8 had not. Therefore, transactions that were waiting to be included in the .7 blockchain could be included in the .8 at any time.

Piper67

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Quote from: molecular on March 12, 2013, 03:48:11 PM

I don't understand how this double-spend even worked. Shouldn't his first tx have ended up in both chains in the first place? Why wasn't it included in the 0.7 chain?

I think the transaction went through during that period where the 0.8 chain was orphaned, and the double spend was sent shortly thereafter. At some point, when the 0.7 chain overtook the 0.8 chain, the original transaction would either have been accepted or rejected, but I have a feeling before that could happen he sent the double spend, caused all the trouble, then quickly posted about his successful double spend.

molecular

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I don't understand how this double-spend even worked. Shouldn't his first tx have ended up in both chains in the first place? Why wasn't it included in the 0.7 chain?

zby

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This is a trivial consequence of the blockchain fork - I think it should be already accounted for in the dip last night, but who knows. I believe nobody will cry when OKPAY reverses the transaction in their system. Overall I think it all was handled much better then I would expect for such an event - but yeah - some merchants might be burned if they were not alert and cannot reverse the payments, so it might get some additional attention. MtGox stopped accepting transfers pretty quickly I think.

Spaceman_Spiff

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Quote from: Elwar on March 12, 2013, 02:26:27 PM

The total amount of BTC traded the 10 transactions after block 225446 adds up to about 145k BTC. That is over $6 million at a price of $45/BTC.

I wonder how much of that $6 million ended up being double spends too.

I would think only a very small minority. I transferred some coins too that were on the wrong chain, but didn't doublespend them.

Also : https://bitcointalksearch.org/topic/bitpays-merchant-processing-during-the-alertfork-last-night-152300

elux

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Quote from: http://en.wikipedia.org/wiki/Bitcoin#Summary

Bitcoin ~~is a solution to the double-spending problem of using a peer-to-peer network to manage transactions.~~

The network timestamps transactions by hashing them into an ongoing chain of hash-based proof-of-work, forming a record or chain that cannot be changed without redoing the proof-of-work. The longest chain of records (called blocks) not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of computing power. ~~As long as a majority of computing power is controlled by nodes that are not cooperating to attack the network, they'll generate the longest chain of records and outpace attackers.~~

Odalv

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Quote from: Elwar on March 12, 2013, 02:26:27 PM

The total amount of BTC traded the 10 transactions after block 225446 adds up to about 145k BTC. That is over $6 million at a price of $45/BTC.

I wonder how much of that $6 million ended up being double spends too.

Maybe(I think) all of them were merged into 0.7 chain automatically. This is what Bitcoin protocol have to do.

Elwar

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Viva Ut Vivas

The total amount of BTC traded the 10 transactions after block 225446 adds up to about 145k BTC. That is over $6 million at a price of $45/BTC.

I wonder how much of that $6 million ended up being double spends too.

Elwar

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Viva Ut Vivas

Quote from: humanitee on March 12, 2013, 02:08:45 PM

Did he do all that before the diverging chain was found out?

Quote

12:53 – After some study, I recognized, the transaction, though included in version 0.8's fork, was never confirmed by the pre-0.8 fork, so I decided to make two double spend transactions on two of the vins of the OKPAY transaction, and broadcasted them with the raw transaction API, 0.001 BTC transaction fee included in each transaction.
13:01 – The double spend transaction was included in pre-0.8 fork block 225446

lucif

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Clown prophet

Hehe... I am sorry for ppl went long.

myself

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chaos is fun...…damental :)

Quote from: Elwar on March 12, 2013, 01:59:19 PM

https://bitcointalksearch.org/topic/a-successful-double-spend-us10000-against-okpay-this-morning-152348

This is no hack of some Bitcoin service, this is a hit to Bitcoin itself.

How low will the price go once this gets out?

be happy it was only 10k

humanitee

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Did he do all that before the diverging chain was found out?

Elwar

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Viva Ut Vivas

https://bitcointalksearch.org/topic/a-successful-double-spend-us10000-against-okpay-this-morning-152348

This is no hack of some Bitcoin service, this is a hit to Bitcoin itself.

How low will the price go once this gets out?

Topic: $10k double spend... - page 3. (Read 4343 times)