Blockchain split of 4 July 2015

[jl2012]

F2Pool is building on a wrong side and there is fake confirmation since block 363731. (EDIT: the bogus chain of 363731 is already orphaned and not relevant to normal users)

If you use light weight wallet or old version of Bitcoin Core, you should stop accepting bitcoin for a moment

EDIT: For people looking for latest advice, please see the header of the forum. If you see no warning in the forum header, you may assume business back to normal

EDIT: More details: https://bitcoin.org/en/alert/2015-07-04-spv-mining

[jonald_fyookball]

interesting,let's see how deep the reorg will be. 

[jonald_fyookball]

Is this for real? A fork would be a big deal.

why is it a big deal?  don't orphan chains happen regularly and get resolved ?

[Quantus]

More info plz

Edit: what do you mean by fake confirmations?

[chalkboard17]

Meanwhile 1mb in transaction on queue https://blockchain.info/unconfirmed-transactions

[Shogen]

So it is not just F2Pool, but also AntPool.
Considering that they have roughly 36% of total network hashrate (data from https://blockchain.info/pools), it shouldn't be hard for the "correct chain" to win.

[Slark]

F2Pool is building on a wrong side and there is fake confirmation since block 363731.

If you use light weight wallet or with old version of Bitcoin Core, you should stop accept bitcoin for a moment

I am using Bitcoin Core (old version, yes I am lazy and paranoid). So basically you are saying if I start my wallet now and it update blockchain it will be corrupted and I will lose access to my coins?

[BitUsher]

https://www.reddit.com/r/Bitcoin/comments/3c2cfd/psa_f2pool_is_mining_invalid_blocks/

tl;dr: of what's going on:

A large % of the hashing power is "SPV mining" where they mine on top of headers from blocks that they haven't actually verified. They're do this because in most cases you earn more money doing it - latency matters a lot and even 1MB blocks take long enough to propagate that you lose a significant amount of money by waiting for full propagation.

However, this also means they're not checking the new BIP66 rule, and are now mining invalid blocks because of it. (another miner happened to create an invalid, non-BIP66 respecting block) If you're not using Bitcoin Core, you might be accepting transactions that won't be on the longest valid chain when all this is fixed.

Bitcoin Core (after 0.10.0) rejects these invalid blocks, but a lot of other stuff doesn't. SPV Bitcoinj wallets do no validation what-so-ever, blindly following the longest chain. blockchain.info doesn't appear to do validation as well; who knows what else?

edit: FWIW, this isn't a BIP66-specific issue: any miner producing an invalid block for any reason would have triggered this issue.

[jonald_fyookball]

Is this for real? A fork would be a big deal.

why is it a big deal?  don't orphan chains happen regularly and get resolved ?

It's certainly not common. Definitely a problem if blockchain.info and the biggest pool in the world are building a different chain.

No direct evidence of that yet though, could be something else.

where are you getting your data that it's not common?  blockchain.info charts show thousands of orphan blocks each day.  sure most of them are probably single blocks, but show me your data please.

[Shogen]

More info plz

Check http://www.reddit.com/r/Bitcoin/comments/3c2cfd/psa_f2pool_is_mining_invalid_blocks/ to get a rough idea of what happened.

BTW, did something like this happen when the BIP 34 soft fork was done?

F2Pool is building on a wrong side and there is fake confirmation since block 363731.

If you use light weight wallet or with old version of Bitcoin Core, you should stop accept bitcoin for a moment

I am using Bitcoin Core (old version, yes I am lazy and paranoid). So basically you are saying if I start my wallet now and it update blockchain it will be corrupted and I will lose access to my coins?

No. All the transaction confirmed before the fork happened (in block 363731) is safe.

[BitUsher]

I am using Bitcoin Core (old version, yes I am lazy and paranoid). So basically you are saying if I start my wallet now and it update blockchain it will be corrupted and I will lose access to my coins?

You run a risk of losing your coins if you perform a transaction at the moment on anything but  Bitcoin Core 0.10.0 or newer. Starting up your wallet is fine though.

If you are using  Bitcoin Core 0.10.0 or newer you will be safe for performing txs at the momment

[OROBTC]

...

Just saw that myself at blockchain.info and came over here for an explanation, right place!

Chinese miners ought to take care not to screw the pooch through selfishness or whatever.

Very unusual things happening are often a bad sign.  I will not do ANY transactions until we get some clarity.

[Quantus]

So the Chines miners are creating invalid blocks but smart phone wallets and even website wallets can't tell they are invalid?

[BitUsher]

Interesting test case for alert being sent out to older version of Bitcoin Core to warn users.(Prior  to 0.10). I have various cores installed on different computers and do not see the alert on any of them.

As far as I am aware 3 people have alert keys - Gavin, Satoshi, and Theymos. Why isn't an alert being sent out?

[jl2012]

So the Chines miners are creating invalid blocks but smart phone wallets and even website wallets can't tell they are invalid?

Yes

[Quantus]

So many people are going to get scammed tonight with fake transactions.

[OROBTC]

...

Been over 30 minutes since the 5 suspicious blocks...

Um, an interesting way to spend a Friday night?

*  *  *

turtlehurricane, a PM for you.  That phone number of yours seems to place you near me.  





EDIT: Has anyone checked the other blockchain tools?  blockexplorer appears to be down / not working.

[Quantus]

We are so fucked

Edit: someone tell me its all going to be ok.

[tokeweed]

[Shogen]

blockchain.info and blocktrail.com are on different chains, this may be proof we really do have a fork.

BIP66 is enforced in block 363275, and since then v2 block should be considered invalid.
BTC Nuggets created a v2 block 363731, but Antpool, F2Pool, and bc.i doesn't not reject it and hence they are now on the wrong fork.