Blockchain split of 4 July 2015

[Lauda]

Detailed explanation(in Chinese)
http://www.8btc.com/bitcoinfork

How about you copy the text here or at least the important part of it. I can rarely access that website from my location.

So, we have to wait 30 confirmations to make sure that it's a real transaction?

Just make sure you're using version 0.10.x. Although you should wait a day or two just to be sure.

[S4VV4S]

Did anybody else notice that (at the time of writing this) the 3 biggest pools have exactly 51% of the total hashrate between them?
I do not think it is relevant. Just an observation.

[CohibAA]

Detailed explanation(in Chinese)
http://www.8btc.com/bitcoinfork

Google Translated to English

July 4 bitcoin block chain bifurcation Comments
I think Bitcoin 2015-07-04 16:09 Posted in Bitcoin 1 139

Today Bitcoin block start diverging from 363,731 Beijing time, to 363,737 returned to normal, the bifurcation five blocks, which lasted one hour or so, most people do not know, and thus did not cause a big impact. Bifurcation 1 block is a normal thing, on a daily basis. But bifurcation five blocks on is not normal, it is necessary to analyze them, in order to avoid this from happening again.
1, mainly due to: block version upgrade from 2 to 3

Today happens to be the block version upgrade from 2 to 3 times, but this time is not scheduled in advance, but is automatically controlled by the program. Upgrade Rules: recent 1000 version blocks 950 blocks of 3, then refused to release the blocks 2 to 3 whole blocks chain upgrading.

Version 2 and version 3 of the difference between: BIP66, namely defining signature DER encoded, no longer accept derive DER encoded, DER accept only standard coding; BIP66 into force method: a recent version 750 block of 3 1 000 blocks, the rules are in effect;

Thus, the upgrade is upgraded in three stages:

(1) When the [0-75%) of the blocks with a version 3, the beginning is compatible with all DER encoding formats, as well as version 2 and 3;
(2) When the> = 75% of the blocks with a version 3, then began to enable BIP66, but is also compatible with version 2;
(3) When the> = 95% of the blocks with a version 3, version 2 is no longer compatible, allowing only 3 version exists.

BTC Nuggets have not been upgraded bitcoind, July 1 and 2, it dug two blocks, then it should not reach the 95% ratio.
9:56 GMT today BTC Nuggets out of the block a version 2 363 726, causing bifurcation, but is bifurcated handling mechanism program resolved.
10:09 BTC Nuggets then a block of 363 731 version 2, which is a fish pond and failed to properly handle ant pool, causing split ends.
2, after the mining bifurcation

After bifurcation within one hour, followed by a fish pond and ants pool of V2 block BTC Nuggets continue dug five blocks, Slush, BitFury and another unknown mineral pool in the main chain dug up four blocks, No other mineral pools dug blocks. Seeing a growing bifurcation, pond and pool ant to BitFury this chain dig, dig the branched five blocks aside, ants dig two pools and BitFury, currency dig a network so that the network is restored normal.

Ponds and pools where ants at BTC Nuggets version 2 block mining, this is confusing. I consulted the fish god, God said that the ants fish tank to the distribution network central node (Note: 5 large ore mine pool after pool conference jointly established a block distribution network designed to block rapid access to the latest, in order to accelerate the mining machine Task Update, improve mining efficiency) Error submitted BTC Nuggets of 363,731 blocks, pond and pool without ant blocks verification in the 363,731 block dug five blocks in a row.

Then I contacted pool 潘志彪 ant, ant pool Panzhi Biao confirmed errors are caused, ants have a node to report the BTC Nuggets version 2 blocks, so that the pond and pool ants are in the wrong block mining.

In short ponds and pools ant task generation process is not to verify the legitimacy of the blocks, resulting in this big fork. Bitcoin bifurcation mechanism can not handle, can only be resolved through a fallback, pond and pool ant rapid rollback, go to the main chain of mining, solved a big problem bifurcation.
3. Summary

Suggestions: (1) bifurcation is not terrible, the most important fast processing (2) Block distribution network is a good thing, but the code to scrutiny (3) the mine pool to make money at the same time, we want more for bitcoin block chain security reasons, do long-term business.

[jwcastle]

This is actually a good thing. I bet people who were resistant on upgrading were terrified that they would lose their bitcoins. I'm sure a large percentage of them have upgraded now.

[Borisz]

I'm using multibit, so I assume I should also wait approx. 30 confirmations just to be safe, right?

(waiting for updates here on how long this "glitch" will last)

[favdesu]

so two chinese pools went unintentionally rogue and forked bitcoin. however, they made a rollback and fixed the problem, does that summarize the issue?

[uvt9]

wasn't the problem fixed shortly ?
those pools went back to valid chain so what are we worrying about ?

[eerygarden]

Flipping technology
https://youtu.be/WeBS-dNo0Bk

Keep calm and carry on hodling

[Limx Dev]

https://bchain.info/BTC/

Problem solved?

[RealBitcoin]

OMG WTF guys? I`m getting scared.

So if i just send now a transaction, then i lose my bitcoins and it doesnt get to the other end?

Also what if i buy now bitcoin with € do i get fake bitcoin if the merchant is on wrong chain?

This could be a serious problem. No FUD intended but seriously, i`m starting to panic/   

[uvt9]

OMG WTF guys? I`m getting scared.

So if i just send now a transaction, then i lose my bitcoins and it doesnt get to the other end?

Also what if i buy now bitcoin with € do i get fake bitcoin if the merchant is on wrong chain?

This could be a serious problem. No FUD intended but seriously, i`m starting to panic/   

OMG WTF please read carefully before getting panic. Everything is settled, those who using Bitcoin core older than 0.10 and was receiving payment during fork period should wait at least 30 confirmations.

[Lauda]

OMG WTF guys? I`m getting scared.

So if i just send now a transaction, then i lose my bitcoins and it doesnt get to the other end?

Also what if i buy now bitcoin with € do i get fake bitcoin if the merchant is on wrong chain?

This could be a serious problem. No FUD intended but seriously, i`m starting to panic/   

Just relax. Why would you panic at all? Obviously you're that kind of person, so how about you just pause everything related to Bitcoin for a day or two?
You don't buy Bitcoin from merchants, but rather on exchanges. Even if something does go wrong I'm pretty sure that Bitstamp would reimburse you.

https://bchain.info/BTC/

Problem solved?

We just need someone to confirm this. I think that everything is fine now, however I can't be sure.

[yohanip]

so two chinese pools went unintentionally rogue and forked bitcoin. however, they made a rollback and fixed the problem, does that summarize the issue?

i think bitcoin system made it's own back choosing for the valid chain

[uvt9]

i think bitcoin system made it's own back choosing for the valid chain

No the system didn't correct itself. It required those pools updating their software in order to mine blocks properly.

[BoikaColor]

Oh, shit !

[Geremia]

Bitcoin-Qt gave me some warning/alert I'd never seen before. Was it related to this blockchain split?

[trasla]

Even though double spending is for sure easier during a fork, remember that the transaction you receive is probably fine for both chains. So even if the confirmations people see from the wrong chain are not valid, its not like every tx sent will just be rolled back or disappear, the miners on the right chain will have heard about your tx as well and even if its not included yet they will likely reject conflicting transactions.

[trasla]

i think bitcoin system made it's own back choosing for the valid chain

No the system didn't correct itself. It required those pools updating their software in order to mine blocks properly.

Of course the system corrected itself, after 6 blocks the wrong chain was overtaken by the correct one.
The fixing and updating of old miners is not needed for bitcoin to work, but for them to still be able to earn money.

[trasla]

Bitcoin-Qt gave me some warning/alert I'd never seen before. Was it related to this blockchain split?

Yes - Gavin used the alert key to put out a warning for all old versions of bitcoin core.
This happens rarely, because its only used for serious situations, and you can get rid of it by updating to the newest version.

[Geremia]

Bitcoin-Qt gave me some warning/alert I'd never seen before. Was it related to this blockchain split?

Yes - Gavin used the alert key to put out a warning for all old versions of bitcoin core.
This happens rarely, because its only used for serious situations, and you can get rid of it by updating to the newest version.

I'm using v0.10.2, and I received the alert.

I saw someone else mentioned it on this thread:

"Your node software is out of date and may accept an invalid blockchain fork. Do not trust confirmations"

That's what I saw, too.