Bitcoin Chain Fork Double Spend Incident - Revision history

Azoundria: Another 30 minutes. Researched and added more history on the BIP. Completed prevention section. Further review and revision of article.

2024-03-15T18:28:25Z

Another 30 minutes. Researched and added more history on the BIP. Completed prevention section. Further review and revision of article.

← Older revision		Revision as of 12:28, 15 March 2024
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	\|-		\|-
	\|February 8th, 2016 9:57:00 PM MST		\|February 8th, 2016 9:57:00 PM MST
	\|Luke Jr		\|Luke Jr Revision
	\|~~February 8th~~, ~~2016 9:57:00 PM MST~~		\|Luke Jr prepares a large number of revisions to improve the clarity of the bitcoin improvement proposal<ref>[https://github.com/bitcoin/bips/commit/072173f3c5290a355e5696b669c3703fcdd47ae3 Changes By Luke Jr To BIP Article - Github] (Accessed Mar 15, 2024)</ref>.
	\|-		\|-
	\|July 13th, 2019 4:25:00 AM MDT		\|July 13th, 2019 4:25:00 AM MDT
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	{{Prevention:Regulators:No Funds Were Lost}}		{{Prevention:Regulators:No Funds Were Lost}}

			Platforms should remain vigilant and have systems in place to receive news of any anomalies present in the blockchain. In the event of anomalies, received transactions should be placed in a pending state until the anomaly has resolved itself.

	{{Prevention:Regulators:Platform Security Assessments}}		{{Prevention:Regulators:Platform Security Assessments}}

Azoundria at 18:20, 15 March 2024

2024-03-15T18:20:31Z

← Older revision		Revision as of 12:20, 15 March 2024
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	{{Case Study Under Construction}}{{Unattributed Sources}}		{{Case Study Under Construction}}{{Unattributed Sources}}

	[[File:Bitcointalk.jpg\|thumb\|Bitcoin Talk Forum]]A larger-than-usual block with more transaction inputs was mined and broadcast, causing a fork in the Bitcoin blockchain. Bitcoin 0.8 nodes managed this well, but pre-0.8 nodes rejected it, resulting in an unexpected split. The 0.8-incompatible chain held about 60% of the mining hash power, preventing an automatic resolution. To restore a ~~canonical~~ chain, BTCGuild and Slush downgraded their Bitcoin 0.8 nodes to 0.7, making the majority hashpower favor the chain without the larger block, eventually causing 0.8 nodes to reorganize to the pre-0.8 chain. During this period, there was a notable double spend, but it was an experiment rather than a malicious act.		[[File:Bitcointalk.jpg\|thumb\|Bitcoin Talk Forum]]A larger-than-usual block with more transaction inputs was mined and broadcast, causing a fork in the Bitcoin blockchain. Bitcoin 0.8 nodes managed this well, but pre-0.8 nodes rejected it, resulting in an unexpected split. The 0.8-based incompatible chain held about 60% of the mining hash power, preventing an automatic resolution. To restore a consistent chain, BTCGuild and Slush downgraded their Bitcoin 0.8 nodes to 0.7, making the majority hashpower favor the chain without the larger block, eventually causing 0.8 nodes to reorganize to the pre-0.8 chain. During this period, there was a notable double spend, but it was an experiment rather than a malicious act.

	This is a global/international case not involving a specific country.<ref name="bips-11433" /><ref name="bitcointalk-11434" />		This is a global/international case not involving a specific country.<ref name="bips-11433" /><ref name="bitcointalk-11434" />
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	== The Reality ==		== The Reality ==
	Insufficient testing had been performed on bitcoin blocks<ref name="bips-11433" />. No testing had been performed with blocks that were smaller in size but required more locks to be established on the BerkeleyDB<ref name="bips-11433" />.		Insufficient testing had been performed on bitcoin blocks<ref name="bips-11433" />. No testing had been performed with blocks that were smaller in size but required more locks to be established on the BerkeleyDB<ref name="bips-11433" />.

			While node operators were instructed to test and increase the setting, the default settings for number of BerkeleyDB locks were inadequate to meet the requirements of the worst-case valid block<ref name="bips-11433" />.

	== What Happened ==		== What Happened ==
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	\|March 20th, 2013 11:01:00 AM MDT		\|March 20th, 2013 11:01:00 AM MDT
	\|Gregory Maxwell Contributes		\|Gregory Maxwell Contributes
	\|Gregory Maxwell expands the BIP article to include that all versions of the bitcoin client prior to 0.8 ~~were affected~~ and added more details. Interestingly, block sizes were set to 500Kb at this time<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&type=revision&diff=36248&oldid=36247 BIP 0050 Gregory Maxwell Changes - Bitcoin Wiki] (Accessed Mar 14, 2024)</ref>.		\|Gregory Maxwell expands the BIP article to include that all versions of the bitcoin client prior to 0.8 would fail to process the 0.8 version block and added more details. Interestingly, block sizes were set to 500Kb at this time<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&type=revision&diff=36248&oldid=36247 BIP 0050 Gregory Maxwell Changes - Bitcoin Wiki] (Accessed Mar 14, 2024)</ref>.
	\|-		\|-
	\|March 22nd, 2013 9:38:00 AM MDT		\|March 22nd, 2013 9:38:00 AM MDT
	\|Randy Brito Critical Contribution		\|Randy Brito Critical Contribution
	\|Randy Brito (of Bitcoin Venezuela)<ref>[https://en.bitcoin.it/wiki/User:Rdymac Randy Brito User Profile - Bitcoin Wiki] (Accessed Mar 14, 2024)</ref> changes "broadcast" to "broadcasted"<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&type=revision&diff=36305&oldid=36249 Randy Brito Broadcasted Change - Bitcoin Wiki] (Accessed Mar 14, 2024)</ref>, despite both being correct and "broadcast" being in far more common use globally<ref>[https://www.michiganpublic.org/podcast/thats-what-they-say/2023-07-09/twts-broadcasting-doubt-about-broadcasted Broadcast Versus Broadcasted - Michigan Public] (Accessed Mar 14, 2024)</ref>.		\|Randy Brito (of Bitcoin Venezuela)<ref>[https://en.bitcoin.it/wiki/User:Rdymac Randy Brito User Profile - Bitcoin Wiki] (Accessed Mar 14, 2024)</ref> changes "broadcast" to "broadcasted"<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&type=revision&diff=36305&oldid=36249 Randy Brito Broadcasted Change - Bitcoin Wiki] (Accessed Mar 14, 2024)</ref>, despite both being correct and "broadcast" being in far more common use globally<ref>[https://www.michiganpublic.org/podcast/thats-what-they-say/2023-07-09/twts-broadcasting-doubt-about-broadcasted Broadcast Versus Broadcasted - Michigan Public] (Accessed Mar 14, 2024)</ref>.
			\|-
			\|May 7th, 2013 12:31:00 PM MDT
			\|Alert System Online
			\|One step of the planned resolution was to implement an alert system in the bitcoind client. This includes 52 test alerts, which are designed to test out whether the alert system is functional or not. Gavin Andresen marked the feature task complete on the Bitcoin Wiki<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&type=revision&diff=37622&oldid=37621 Gavin Andresen Marks Alert System Complete - Bitcoin Wiki] (Accessed Mar 15, 2024)</ref>, after erroneously marking the test alerts complete<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&type=revision&diff=37621&oldid=36305 Test Alerts Marked Complete - Bitcoin Wiki] (Accessed Mar 15, 2024)</ref>.
			\|-
			\|June 22nd, 2013 5:50:00 AM MDT
			\|Test Alerts Set Up
			\|The test alerts are finally set up, allowing clients to test out the alertnotify feature with weekly notifications<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&type=revision&diff=38840&oldid=37622 Test Alert System Online - Bitcoin Wiki] (Accessed Mar 15, 2024)</ref>. There is also an alert which is set up to automatically trigger if a longer side-chain is detected, although this feature is still "pending review"<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&type=revision&diff=38841&oldid=38840 Side Chain Alert System Pending Review - Bitcoin Wiki] (Accessed Mar 15, 2024)</ref>.
			\|-
			\|August 13th, 2013 3:01:00 AM MDT
			\|Side Chain Alert Patch Merged In
			\|The automatic alerts if a side chain is detected is merged into bitcoin core<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&type=revision&diff=40115&oldid=38841 Side Chain Alert System Merged In - Bitcoin Wiki] (Accessed Mar 15, 2024)</ref>.
			\|-
			\|August 16th, 2013
			\|Block 252451 Rejected
			\|The acceptance of block 252,451 by the main chain marked the first time that unpatched nodes were no longer able to use the bitcoin blockchain<ref name=":0">[https://en.bitcoin.it/w/index.php?title=BIP_0050&type=revision&diff=40483&oldid=40482 Unpatched Nodes Forked Off Chain - Bitcoin Wiki] (Accessed Mar 15, 2024)</ref><ref name=":1">[https://en.bitcoin.it/w/index.php?title=BIP_0050&type=revision&diff=40481&oldid=40115 Block 22451 Is Rejected - Bitcoin Wiki] (Accessed Mar 15, 2024)</ref>.
			\|-
			\|August 25th, 2013 4:55:00 PM MDT
			\|Gavin Andresen Wrong Block
			\|Gavin Andresen updates the Bitcoin Wiki to indicate the resolution of the situation, however he claims that block 22,451 was the fork point and gives a date of August 22nd, 2013<ref name=":1" />. This is corrected within 10 minutes<ref name=":0" />.
			\|-
			\|October 20th, 2013 10:57:00 PM MDT
			\|Peter Todd Archives BIP
			\|Peter Todd moves the content of the Bitcoin Wiki to be archived on Github<ref>[https://github.com/bitcoin/bips/commit/03dd8c73d5055aa2f02ede4c4b1fae975677def7 BIP 0050 Archived On Github - Github] (Accessed Mar 15, 2024)</ref>.
			\|-
			\|December 6th, 2013 1:08:00 AM MST
			\|BIP Moved To Github
			\|The bitcoin improvement proposal is relocated to Github via an official blanking out of the Bitcoin Wiki page<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&type=revision&diff=42925&oldid=42614 BIP 0050 Relocated To Github - Bitcoin Wiki] (Accessed Mar 15, 2024)</ref>.
			\|-
			\|February 8th, 2016 9:57:00 PM MST
			\|Luke Jr
			\|February 8th, 2016 9:57:00 PM MST
	\|-		\|-
	\|July 13th, 2019 4:25:00 AM MDT		\|July 13th, 2019 4:25:00 AM MDT
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	== Technical Details ==		== Technical Details ==



	"A block that had a larger number of total transaction inputs than previously seen was mined and broadcasted. Bitcoin 0.8 nodes were able to handle this, but some pre-0.8 Bitcoin nodes rejected it, causing an unexpected fork of the blockchain. The pre-0.8-incompatible chain (from here on, the 0.8 chain) at that point had around 60% of the mining hash power ensuring the split did not automatically resolve (as would have occurred if the pre-0.8 chain outpaced the 0.8 chain in total work, forcing 0.8 nodes to reorganise to the pre-0.8 chain).		"A block that had a larger number of total transaction inputs than previously seen was mined and broadcasted. Bitcoin 0.8 nodes were able to handle this, but some pre-0.8 Bitcoin nodes rejected it, causing an unexpected fork of the blockchain. The pre-0.8-incompatible chain (from here on, the 0.8 chain) at that point had around 60% of the mining hash power ensuring the split did not automatically resolve (as would have occurred if the pre-0.8 chain outpaced the 0.8 chain in total work, forcing 0.8 nodes to reorganise to the pre-0.8 chain).

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	== Individual Prevention Policies ==		== Individual Prevention Policies ==
	{{Prevention:Individuals:No Individual Funds Lost}}		{{Prevention:Individuals:No Individual Funds Lost}}

			Based on the research, losses were noted against large exchange platforms only. There were no cases reported where an individual lost funds.

			While such situations are rare, if a large value is being transacted, it makes sense to wait for a larger number of confirmations before

			{{Prevention:Individuals:Double Check Transactions}}

	{{Prevention:Individuals:End}}		{{Prevention:Individuals:End}}

	== Platform Prevention Policies ==		== Platform Prevention Policies ==
	{{Prevention:Platforms:~~Placeholder~~}}		{{Prevention:Platforms:No Platform Funds Lost}}

			Platforms should remain vigilant and have systems in place to receive news of any anomalies present in the blockchain. In the event of anomalies, received transactions should be placed in a pending state until the anomaly has resolved itself.

			{{Prevention:Platforms:Regular Audit Procedures}}

			As this situation took place at the protocol layer, prevention through process is challenging. The only solution which can work 100% is to insure wallets against double-spend attacks.

			{{Prevention:Platforms:Establish Industry Insurance Fund}}

	{{Prevention:Platforms:End}}		{{Prevention:Platforms:End}}

	== Regulatory Prevention Policies ==		== Regulatory Prevention Policies ==
	{{Prevention:Regulators:~~Placeholder~~}}		{{Prevention:Regulators:No Funds Were Lost}}


			{{Prevention:Regulators:Platform Security Assessments}}

			{{Prevention:Regulators:Establish Industry Insurance Fund}}

	{{Prevention:Regulators:End}}		{{Prevention:Regulators:End}}

Azoundria at 18:50, 14 March 2024

2024-03-14T18:50:06Z

← Older revision		Revision as of 12:50, 14 March 2024
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	{{Case Study Under Construction}}{{Unattributed Sources}}		{{Case Study Under Construction}}{{Unattributed Sources}}

	[[File:Bitcointalk.jpg\|thumb\|Bitcoin Talk Forum]]A larger-than-usual block with more transaction inputs was mined and ~~broadcasted~~, causing a fork in the Bitcoin blockchain. Bitcoin 0.8 nodes managed this well, but pre-0.8 nodes rejected it, resulting in an unexpected split. The 0.8-incompatible chain held about 60% of the mining hash power, preventing an automatic resolution. To restore a canonical chain, BTCGuild and Slush downgraded their Bitcoin 0.8 nodes to 0.7, making the majority hashpower favor the chain without the larger block, eventually causing 0.8 nodes to reorganize to the pre-0.8 chain. During this period, there was a notable double spend, but it was an experiment rather than a malicious act.		[[File:Bitcointalk.jpg\|thumb\|Bitcoin Talk Forum]]A larger-than-usual block with more transaction inputs was mined and broadcast, causing a fork in the Bitcoin blockchain. Bitcoin 0.8 nodes managed this well, but pre-0.8 nodes rejected it, resulting in an unexpected split. The 0.8-incompatible chain held about 60% of the mining hash power, preventing an automatic resolution. To restore a canonical chain, BTCGuild and Slush downgraded their Bitcoin 0.8 nodes to 0.7, making the majority hashpower favor the chain without the larger block, eventually causing 0.8 nodes to reorganize to the pre-0.8 chain. During this period, there was a notable double spend, but it was an experiment rather than a malicious act.

	This is a global/international case not involving a specific country.<ref name="bips-11433~~" /><ref name="newsletterarchive-11417~~" /><ref name="bitcointalk-11434" />		This is a global/international case not involving a specific country.<ref name="bips-11433" /><ref name="bitcointalk-11434" />

	== About Bitcoin ==		== About Bitcoin ==
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	\|March 20th, 2013 10:34:00 AM MDT		\|March 20th, 2013 10:34:00 AM MDT
	\|Post-Mortem Released		\|Post-Mortem Released
	\|A post-mortem is released by Gavin Andresen with additional details about the incident on the Bitcoin Wiki<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&oldid=36239 BIP_0050 Original Version From March 20th, 2013 10:34:00 AM MDT - Bitcoin Wiki] (Accessed Mar 8, 2024)</ref>.		\|A post-mortem / bitcoin improvement proposal is released by Gavin Andresen with additional details about the incident on the Bitcoin Wiki<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&oldid=36239 BIP_0050 Original Version From March 20th, 2013 10:34:00 AM MDT - Bitcoin Wiki] (Accessed Mar 8, 2024)</ref>. The BIP number 50 is assigned shortly thereafter.
			\|-
			\|March 20th, 2013 11:01:00 AM MDT
			\|Gregory Maxwell Contributes
			\|Gregory Maxwell expands the BIP article to include that all versions of the bitcoin client prior to 0.8 were affected and added more details. Interestingly, block sizes were set to 500Kb at this time<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&type=revision&diff=36248&oldid=36247 BIP 0050 Gregory Maxwell Changes - Bitcoin Wiki] (Accessed Mar 14, 2024)</ref>.
			\|-
			\|March 22nd, 2013 9:38:00 AM MDT
			\|Randy Brito Critical Contribution
			\|Randy Brito (of Bitcoin Venezuela)<ref>[https://en.bitcoin.it/wiki/User:Rdymac Randy Brito User Profile - Bitcoin Wiki] (Accessed Mar 14, 2024)</ref> changes "broadcast" to "broadcasted"<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&type=revision&diff=36305&oldid=36249 Randy Brito Broadcasted Change - Bitcoin Wiki] (Accessed Mar 14, 2024)</ref>, despite both being correct and "broadcast" being in far more common use globally<ref>[https://www.michiganpublic.org/podcast/thats-what-they-say/2023-07-09/twts-broadcasting-doubt-about-broadcasted Broadcast Versus Broadcasted - Michigan Public] (Accessed Mar 14, 2024)</ref>.
	\|-		\|-
	\|July 13th, 2019 4:25:00 AM MDT		\|July 13th, 2019 4:25:00 AM MDT
	\|Hack Used As Example		\|Hack Used As Example
	\|Eric Wall references the chain split in a discussion to refute the statement that "The Bitcoin blockchain has never been hacked"<ref>[https://twitter.com/ercwl/status/1149988326029574144 ercwl - "$10,000 double-spend against OKPAY as a result of the 2013 LevelDB/BerkeleyDB chainsplit" - Twitter] (Accessed Mar 12, 2024)</ref>.		\|Eric Wall references the chain split in a discussion to refute the statement that "The Bitcoin blockchain has never been hacked"<ref>[https://twitter.com/ercwl/status/1149988326029574144 ercwl - "$10,000 double-spend against OKPAY as a result of the 2013 LevelDB/BerkeleyDB chainsplit" - Twitter] (Accessed Mar 12, 2024)</ref>.
			\|-
			\|October 10th, 2022 8:52:34 AM MDT
			\|Stoppable Finance Bankless Article
			\|The incident is included in an article by Stoppable Finance when comparing bitcoin against Solana<ref name="newsletterarchive-11417" />. "Bitcoin has had two network outages since its inception"<ref name="newsletterarchive-11417" />.
	\|}		\|}

Azoundria: Another 30 minutes. Filled in information from the blockchain transactions found, as well as a further review of the BitcoinTalk thread. Expansion and improvement of the article and timeline.

2024-03-13T21:30:00Z

Another 30 minutes. Filled in information from the blockchain transactions found, as well as a further review of the BitcoinTalk thread. Expansion and improvement of the article and timeline.

← Older revision		Revision as of 15:30, 13 March 2024
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	== What Happened ==		== What Happened ==
	~~A double-spend transaction occurred due to the~~ blockchain split.		The bitcoin blockchain split into two, with 0.8+ version nodes running a separate chain. A double-spend transaction was able to occur against the BTC-e exchange at this time.

	~~"08:08 – Well before I knew what later have happened~~, ~~I deposited $10000-worth Bitcoins to BTC-e over OKPAY's Bitcoin payment, I paid OKPAY address 12z2n8YCJw1BEsJhhQPLCTuLqwH341nKnE 211.9093 BTC and~~ 0.~~0005 BTC as transaction fee.~~

	~~09:30 – The transaction was included in~~ version 0.~~8's fork, block 225446~~

	~~10:08 – Deposit completed, $9800 credited to my BTC~~-~~e account~~

	~~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"~~
	{\| class="wikitable"		{\| class="wikitable"
	\|+Key Event Timeline - Bitcoin Chain Fork Double Spend Incident		\|+Key Event Timeline - Bitcoin Chain Fork Double Spend Incident
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	\|March 12th, 2013 12:22:02 PM MDT		\|March 12th, 2013 12:22:02 PM MDT
	\|Bitcoin Talk Post		\|Bitcoin Talk Post
	\|An article about the double spend and the timeline of events is posted on the Bitcoin Talk forum<ref name="bitcointalk-11434" />.		\|An article about the double spend and the timeline of events is posted on the Bitcoin Talk forum<ref name="bitcointalk-11434" />. The sequence of events began with a deposit of $10,000 worth of Bitcoins to BTC-e over OKPAY's Bitcoin payment, resulting in $9800 credited to the BTC-e account. However, it was later realized that the transaction was never confirmed by the pre-0.8 fork, prompting the initiator to execute two double spend transactions on two of the vins of the OKPAY transaction. These transactions were broadcasted with the raw transaction API, each including a 0.001 BTC transaction fee. Subsequently, the double spend transaction was included in the pre-0.8 fork block 225446. This incident raised concerns about the security of Bitcoin transactions and prompted discussions about potential solutions to prevent similar occurrences in the future, highlighting the need for heightened vigilance among merchants considering Bitcoin transactions<ref name="bitcointalk-11434" />.
			\|-
			\|March 13th, 2013 3:49:16 AM MDT
			\|Announcement Of Fund Return
			\|Okpay announces that the funds have been returned in the BitcoinTalk forum<ref>[https://bitcointalk.org/index.php?topic=152348.msg1619633#msg1619633 OkPay - "The payment has been successfully completed" - BitcoinTalk] (Accessed Mar 13, 2024)</ref>.
			\|-
			\|March 13th, 2013 3:57:47 AM MDT
			\|Funds Returned In Blockchain
			\|Blockchain transaction believed to be the return of the funds which were taken through the double-spend<ref>[https://www.blockchain.com/explorer/transactions/btc/cf7121622d6b208357b2a115cc75a9be283f8996dd7d6f612923b30f600bcadd Transaction Returning The Funds - Blockchain.com] (Accessed Mar 13, 2024)</ref>.
	\|-		\|-
	\|March 20th, 2013 10:34:00 AM MDT		\|March 20th, 2013 10:34:00 AM MDT
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	https://web.archive.org/web/20130315031720/http://blockchain.info/tx/12814b8ad57ce5654ba69eb26a52ddae1bff42093ca20cef3ad96fe7fd85d195		https://web.archive.org/web/20130315031720/http://blockchain.info/tx/12814b8ad57ce5654ba69eb26a52ddae1bff42093ca20cef3ad96fe7fd85d195


			Payout transaction: https://www.blockchain.com/explorer/transactions/btc/cf7121622d6b208357b2a115cc75a9be283f8996dd7d6f612923b30f600bcadd


			<ref>https://bitcointalk.org/index.php?topic=152348.msg1617466#msg1617466 (Accessed Mar 13, 2024)</ref><blockquote>gmaxwell answered it: a large majority of mining power ''switched'' to running 0.7 -- which meant restarting the miners and clearing their memory pools. With the right dynamics, a rebroadcast would not repropagate because most nodes had not been restarted and would not rebroadcast it. Thus, those miners that restarted, started mining without it, and accepted the double-spend as a first-spend.</blockquote>

	== Total Amount Lost ==		== Total Amount Lost ==
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	== Immediate Reactions ==		== Immediate Reactions ==
	~~How did the various parties involved (firm, platform, management, and/or affected individual(s)) deal with the events? Were services shut down? Were announcements made? Were groups formed?~~		Large mining pools BTC Guild and SlushPool reverted their bitcoin clients back to the 0.7 version of the chain and continued to mine on 0.7. This resulted in 0.7 resuming the longest chain.

	Large mining pools reverted their bitcoin clients back to the 0.7 version of the chain.

	== Ultimate Outcome ==		== Ultimate Outcome ==

Azoundria: Another 30 minutes. Added timeline information from BitcoinTalk thread. Researched the transaction data in the block explorer. Further revisions to content.

2024-03-12T17:35:30Z

Another 30 minutes. Added timeline information from BitcoinTalk thread. Researched the transaction data in the block explorer. Further revisions to content.

← Older revision		Revision as of 11:35, 12 March 2024
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	!Description		!Description
	\|-		\|-
	\|March 12th, 2013 6:22:02 PM MDT		\|March 12th, 2013 2:08:00 AM MDT
			\|BTC-E Deposit Made
			\|"Well before I knew what later have happened, I deposited $10000-worth Bitcoins to BTC-e over OKPAY's Bitcoin payment, I paid OKPAY address 12z2n8YCJw1BEsJhhQPLCTuLqwH341nKnE 211.9093 BTC and 0.0005 BTC as transaction fee."<ref name="bitcointalk-11434" />
			\|-
			\|March 12th, 2013 3:30:00 AM MDT
			\|Transaction Included
			\|"The transaction was included in version 0.8's fork, block 225446"<ref name="bitcointalk-11434" />
			\|-
			\|March 12th, 2013 4:08:00 AM MDT
			\|Credit To BTC-E Account
			\|"Deposit completed, $9800 credited to my BTC-e account"<ref name="bitcointalk-11434" />
			\|-
			\|March 12th, 2013 6:53:00 AM MDT
			\|Replay Withdrawal To Pre-0.8 Chain
			\|"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."<ref name="bitcointalk-11434" />
			\|-
			\|March 12th, 2013 7:01:00 AM MDT
			\|Double Spend Transaction Included
			\|"The double spend transaction was included in pre-0.8 fork block 225446"<ref name="bitcointalk-11434" />
			\|-
			\|March 12th, 2013 12:22:02 PM MDT
	\|Bitcoin Talk Post		\|Bitcoin Talk Post
	\|~~The incident~~ and a timeline ~~are~~ posted on the Bitcoin Talk forum<ref name="bitcointalk-11434" />.		\|An article about the double spend and the timeline of events is posted on the Bitcoin Talk forum<ref name="bitcointalk-11434" />.
	\|-		\|-
	\|March 20th, 2013 10:34:00 AM MDT		\|March 20th, 2013 10:34:00 AM MDT
	\|Post-Mortem Released		\|Post-Mortem Released
	\|A post-mortem is released by Gavin Andresen with additional details about the incident on the Bitcoin Wiki<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&oldid=36239 BIP_0050 Original Version From March 20th, 2013 10:34:00 AM MDT - Bitcoin Wiki] (Accessed Mar 8, 2024)</ref>.		\|A post-mortem is released by Gavin Andresen with additional details about the incident on the Bitcoin Wiki<ref>[https://en.bitcoin.it/w/index.php?title=BIP_0050&oldid=36239 BIP_0050 Original Version From March 20th, 2013 10:34:00 AM MDT - Bitcoin Wiki] (Accessed Mar 8, 2024)</ref>.
			\|-
			\|July 13th, 2019 4:25:00 AM MDT
			\|Hack Used As Example
			\|Eric Wall references the chain split in a discussion to refute the statement that "The Bitcoin blockchain has never been hacked"<ref>[https://twitter.com/ercwl/status/1149988326029574144 ercwl - "$10,000 double-spend against OKPAY as a result of the 2013 LevelDB/BerkeleyDB chainsplit" - Twitter] (Accessed Mar 12, 2024)</ref>.
	\|}		\|}

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	Note that BDB locks are also required during processing of re-organizations. Versions prior to 0.8 may be unable to process some valid re-orgs."		Note that BDB locks are also required during processing of re-organizations. Versions prior to 0.8 may be unable to process some valid re-orgs."

			The transaction, presently invalid based on the current bitcoin blockchain<ref>[https://www.blockchain.com/explorer/transactions/btc/12814b8ad57ce5654ba69eb26a52ddae1bff42093ca20cef3ad96fe7fd85d195 Double Spent Deposit To BTC-E - Blockchain] (Accessed Mar 12, 2024)</ref><ref>[https://web.archive.org/web/20130315031720/http://blockchain.info/tx/12814b8ad57ce5654ba69eb26a52ddae1bff42093ca20cef3ad96fe7fd85d195 Blockchain Transaction Double-Spent Deposit To BTC-E - Blockchain Archive March 14th, 2013 9:17:20 PM MDT] (Accessed Mar 12, 2024)</ref>:

			[https://www.blockchain.com/explorer/transactions/btc/12814b8ad57ce5654ba69eb26a52ddae1bff42093ca20cef3ad96fe7fd85d195 12814b8ad57ce5654ba69eb26a52ddae1bff42093ca20cef3ad96fe7fd85d195]

			https://web.archive.org/web/20130315031720/http://blockchain.info/tx/12814b8ad57ce5654ba69eb26a52ddae1bff42093ca20cef3ad96fe7fd85d195

	== Total Amount Lost ==		== Total Amount Lost ==
Line 74:		Line 104:
	This situation meant that older nodes which did not implement that improvement proposal or manually increase their number of supported locks would not be able to validate the bitcoin blockchain.		This situation meant that older nodes which did not implement that improvement proposal or manually increase their number of supported locks would not be able to validate the bitcoin blockchain.
	== Individual Prevention Policies ==		== Individual Prevention Policies ==
	{{Prevention:Individuals:~~Placeholder~~}}		{{Prevention:Individuals:No Individual Funds Lost}}

	{{Prevention:Individuals:End}}		{{Prevention:Individuals:End}}

Azoundria: Another 30 minutes. Review of the BIP and tracing back the history of the BIP. Updated with information from the bitcoin wiki. Removed a broken source link which couldn't be found in any archive. Structuring information from the about section to other relevant sections.

2024-03-08T17:49:56Z

Another 30 minutes. Review of the BIP and tracing back the history of the BIP. Updated with information from the bitcoin wiki. Removed a broken source link which couldn't be found in any archive. Structuring information from the about section to other relevant sections.

Show changes

Azoundria: Created page with "{{Imported Case Study|source=https://www.quadrigainitiative.com/casestudy/bitcoinchainforkdoublespendincident.php}} {{Unattributed Sources}} Bitcoin Talk ForumA larger-than-usual block with more transaction inputs was mined and broadcasted, causing a fork in the Bitcoin blockchain. Bitcoin 0.8 nodes managed this well, but pre-0.8 nodes rejected it, resulting in an unexpected split. The 0.8-incompatible chain held about 60% of the mining ha..."

2023-08-20T18:25:10Z

Created page with "{{Imported Case Study|source=https://www.quadrigainitiative.com/casestudy/bitcoinchainforkdoublespendincident.php}} {{Unattributed Sources}} thumb|Bitcoin Talk ForumA larger-than-usual block with more transaction inputs was mined and broadcasted, causing a fork in the Bitcoin blockchain. Bitcoin 0.8 nodes managed this well, but pre-0.8 nodes rejected it, resulting in an unexpected split. The 0.8-incompatible chain held about 60% of the mining ha..."

New page

{{Imported Case Study|source=https://www.quadrigainitiative.com/casestudy/bitcoinchainforkdoublespendincident.php}}
{{Unattributed Sources}}

[[File:Bitcointalk.jpg|thumb|Bitcoin Talk Forum]]A larger-than-usual block with more transaction inputs was mined and broadcasted, causing a fork in the Bitcoin blockchain. Bitcoin 0.8 nodes managed this well, but pre-0.8 nodes rejected it, resulting in an unexpected split. The 0.8-incompatible chain held about 60% of the mining hash power, preventing an automatic resolution. To restore a canonical chain, BTCGuild and Slush downgraded their Bitcoin 0.8 nodes to 0.7, making the majority hashpower favor the chain without the larger block, eventually causing 0.8 nodes to reorganize to the pre-0.8 chain. During this period, there was a notable double spend, but it was an experiment rather than a malicious act.

This is a global/international case not involving a specific country.<ref name="newsletter-11414" /><ref name="bips-11433" /><ref name="newsletterarchive-11417" /><ref name="bitcointalk-11434" />

== About Bitcoin ==
"A block that had a larger number of total transaction inputs than previously seen was mined and broadcasted. Bitcoin 0.8 nodes were able to handle this, but some pre-0.8 Bitcoin nodes rejected it, causing an unexpected fork of the blockchain. The pre-0.8-incompatible chain (from here on, the 0.8 chain) at that point had around 60% of the mining hash power ensuring the split did not automatically resolve (as would have occurred if the pre-0.8 chain outpaced the 0.8 chain in total work, forcing 0.8 nodes to reorganise to the pre-0.8 chain).

In order to restore a canonical chain as soon as possible, BTCGuild and Slush downgraded their Bitcoin 0.8 nodes to 0.7 so their pools would also reject the larger block. This placed majority hashpower on the chain without the larger block, thus eventually causing the 0.8 nodes to reorganise to the pre-0.8 chain."

"During this time there was at least one large double spend. However, it was done by someone experimenting to see if it was possible and was not intended to be malicious."

"Because max-sized blocks had been successfully processed on the testnet, it did not occur to anyone that there could be blocks that were smaller but require more locks than were available. Prior to 0.7 unmodified mining nodes self-imposed a maximum block size of 500,000 bytes, which further prevented this case from being triggered. 0.7 made the target size configurable and miners had been encouraged to increase this target in the week prior to the incident.

Bitcoin 0.8 did not use Berkeley DB. It switched to LevelDB instead, which did not implement the same locking limits as BDB. Therefore it was able to process the forking block successfully.

Note that BDB locks are also required during processing of re-organizations. Versions prior to 0.8 may be unable to process some valid re-orgs."

"08:08 – Well before I knew what later have happened, I deposited $10000-worth Bitcoins to BTC-e over OKPAY's Bitcoin payment, I paid OKPAY address 12z2n8YCJw1BEsJhhQPLCTuLqwH341nKnE 211.9093 BTC and 0.0005 BTC as transaction fee.
09:30 – The transaction was included in version 0.8's fork, block 225446
10:08 – Deposit completed, $9800 credited to my BTC-e account
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"

This is a global/international case not involving a specific country.

The background of the exchange platform, service, or individuals involved, as it would have been seen or understood at the time of the events.

Include:

* Known history of when and how the service was started.
* What problems does the company or service claim to solve?
* What marketing materials were used by the firm or business?
* Audits performed, and excerpts that may have been included.
* Business registration documents shown (fake or legitimate).
* How were people recruited to participate?
* Public warnings and announcements prior to the event.

Don't Include:
* Any wording which directly states or implies that the business is/was illegitimate, or that a vulnerability existed.
* Anything that wasn't reasonably knowable at the time of the event.
There could be more than one section here. If the same platform is involved with multiple incidents, then it can be linked to a main article page.

== The Reality ==
This sections is included if a case involved deception or information that was unknown at the time. Examples include:

* When the service was actually started (if different than the "official story").
* Who actually ran a service and their own personal history.
* How the service was structured behind the scenes. (For example, there was no "trading bot".)
* Details of what audits reported and how vulnerabilities were missed during auditing.

== What Happened ==
The specific events of the loss and how it came about. What actually happened to cause the loss and some of the events leading up to it.
{| class="wikitable"
|+Key Event Timeline - Bitcoin Chain Fork Double Spend Incident
!Date
!Event
!Description
|-
|March 12th, 2013 6:22:02 PM MDT
|Bitcoin Talk Post
|The incident and a timeline are posted on the Bitcoin Talk forum.
|}

== Technical Details ==
This section includes specific detailed technical analysis of any security breaches which happened. What specific software vulnerabilities contributed to the problem and how were they exploited?

== Total Amount Lost ==
The total amount lost has been estimated at $10,000 USD.

How much was lost and how was it calculated? If there are conflicting reports, which are accurate and where does the discrepancy lie?

== Immediate Reactions ==
How did the various parties involved (firm, platform, management, and/or affected individual(s)) deal with the events? Were services shut down? Were announcements made? Were groups formed?

== Ultimate Outcome ==
What was the end result? Was any investigation done? Were any individuals prosecuted? Was there a lawsuit? Was any tracing done?

== Total Amount Recovered ==
The total amount recovered has been estimated at $10,000 USD.

What funds were recovered? What funds were reimbursed for those affected users?

== Ongoing Developments ==
What parts of this case are still remaining to be concluded?
== Individual Prevention Policies ==
{{Prevention:Individuals:Placeholder}}

{{Prevention:Individuals:End}}

== Platform Prevention Policies ==
{{Prevention:Platforms:Placeholder}}

{{Prevention:Platforms:End}}

== Regulatory Prevention Policies ==
{{Prevention:Regulators:Placeholder}}

{{Prevention:Regulators:End}}

== References ==
<references><ref name="newsletter-11414">[https://newsletter.banklesshq.com/p/stoppable-finance-lite https://newsletter.banklesshq.com/p/stoppable-finance-lite] (Oct 11, 2022)</ref>

<ref name="bips-11433">[https://bips.xyz/50?utm_source=substack&utm_medium=email https://bips.xyz/50?utm_source=substack&utm_medium=email] (Oct 11, 2022)</ref>

<ref name="newsletterarchive-11417">[https://web.archive.org/web/20221010212053/https://newsletter.banklesshq.com/p/stoppable-finance-lite <nowiki>Stoppable Finance [LITE] - by Donovan Choy - Bankless</nowiki>] (Jul 24, 2023)</ref>

<ref name="bitcointalk-11434">[https://bitcointalk.org/index.php?topic=152348.0 A successful DOUBLE SPEND US$10000 against OKPAY this morning.] (Aug 14, 2023)</ref></references>