Bitcoin Fork Monitor

This web site looks like a good dashboard! Although, I'm not up on the technical details of everything going on here, so some of it is confusing to me, because there's not as much background as I'd like.

I've spent some time reading around, and here is my guess as to what the site is describing:

Behind the scenes, achow101 (https://github.com/achow101) is running four Bitcoin clients:

* `Bitcoin Core` is running the client from https://bitcoin.org/en/ (https://github.com/bitcoin/bitcoin) (https://bitcoincore.org). This client does not support Segregated Witness, and it does not support larger block sizes (so blocks larger than 1 MB are ignored).

* `UASF (BIP 148)` is running the client from https://bitcoinuasf.org (https://github.com/UASF/bitcoin). This client supports Segregated Witness. This client does not support larger block sizes (so blocks larger than 1 MB are ignored).

* `btc1 (segwit2x)` is running the client from https://segwit2x.github.io (https://github.com/btc1/bitcoin). This client supports Segregated Witness, as well as changing the block size to 2 MB (blocks larger than 2 MB are ignored).

* `Bitcoin ABC (UAHF)` is running the client from https://www.bitcoinabc.org (https://github.com/Bitcoin-ABC/bitcoin-abc). It supports blocks of <8 MB in size (initially defaulting to 2 MB). This client does not support Segregated Witness.

As I understand things, right now there are two events which have hard-coded dates:

* At midnight UTC on August 1, the `UASF (BIP 148)` client will fork, in that it will start ignoring new mined blocks which do not support Segregated Witness.

* At 12:20 UTC on August 1, the `Bitcoin ABC (UAHF)` client might fork. I say might because the fork will be triggered by someone mining a larger-than-1-MB block (the "trigger block") on or after 12:20 UTC. (1 MB is the largest block that the `Bitcoin Core` and `UASF (BIP 148)` clients will recognize). At that point, `Bitcoin ABC (UAHF)` nodes will treat the "trigger block" as valid, and the fork has occurred.

Also, there is another event which may take place, depending on various conditions:

* If—sometime soon (before midnight UTC on August 1), and for a long-enough period—enough people indicate support, then the `btc1 (segwit2x)` node will fork with the `UASF (BIP 148)` node (in that both nodes will start supporting Segregated Witness). Sometime after that fork, the `btc1 (segwit2x)` node will fork off into its own fork, which will have support for 2 MB blocks.

And of course, there is one event which will happen at some point:

* `Bitcoin Core` will release a new version, adding support for Segregated Witness, or for a different block size, or both. `Bitcoin Core` nodes, when they upgrade, will then join one of the forks.

Anyway, I _think_ that's right, but this has gotten really complicated, and I'm trying to skip over the specific details, and the rationale (since, as tempay mentioned, that's been discussed recently).

If I misunderstood something, please let me know!

thelsdj• 9 years ago

I'm pretty sure the Bitcoin Core client supports Segregated Witness fine. I believe it will follow whatever the longest chain is (as long as its not larger than 1MB).

tomtomtom7772• 9 years ago

You are correct, but as it seems almost certain at this point that SegWit2X (btc1) will reach its threshold in time, we can simplify.

SegWit2x rejects non-SegWit blocks. So with the majority it has it can't cause a fork in the chain (until the HF 3 months later), and neither will BIP148.

So with the rather safe assumption SegWit2X reaches its threshold in the next few days, the only expected fork in the chain by August will be Bitcoin Cash (Bitcoin ABC/BU/big blocks) on one chain and Segwit on the other.

lz4002• 9 years ago

So to super-simplify it. Who wins with this assumed scenario, the scale on chain/big blockers or the off chain/blockstream faction?

hasch• 9 years ago

the issue could be that they signal bip91, it's going to be activated, but they aren't running the actual code for rejecting the non segwit blocks

Capt-RogerOver• 9 years ago

You had an error there about Bitcoin Core (github.com/bitcoin/bitcoin). It supports SegWit: https://bitcoinmagazine.com/articles/bitcoin-core-0141-segwi...

SkyMarshal• 9 years ago

`Bitcoin Core` is running the client from https://bitcoin.org/en/ (https://github.com/bitcoin/bitcoin) (https://bitcoincore.org). This client does not support Segregated Witness, and it does not support larger block sizes (so blocks larger than 1 MB are ignored).

Just to clarify a bit more, this is the original Bitcoin client that Satoshi and Hal Finney created, and which has been the canonical client from the beginning. Bitcoin Core develops this client, and they invented SegWit, so it definitely supports it.

kbody3• 9 years ago

You should add SEGSIGNAL/BIP91 https://github.com/segsignal/bitcoin which is at the moment the lead for starting the activation.

jstanley2• 9 years ago

You mean like:

bip91: 178/223 (79.82% signalling) (269/336 Threshold)

kbody3• 9 years ago

Signalling and node software are not coupled. The point of this is to see how each node software behaves, there are miners that don't run Segwit2x/BTC1 but rather Segsignal.

kbody3• 9 years ago

Got downvoted for some reason, I guess some people don't understand how crucial this is. BIP91 was signaled mostly with this node software. This node is what matters the most since it will show if miners get reorged.

dm319• 9 years ago

Anyone know how much energy is created from the chain splitting?

sonium2• 9 years ago

A more visual approach, but different underlying concept here: https://coin.dance/blocks

tiku• 9 years ago

I was wondering, why the bitcoin owners themself cant't decide. Because a bitcoin can be seen as a SHARE, as well as money. So someone who has a lot of bitcoins is a bigger shareholder and should have more to say about it. The how etc to show how much coins you have etc is another issue, but i believe this should be the way to go.

sonium2• 9 years ago

Once there are hardforks, people will be able to 'vote with their wallets', and a consensus will be apparent through exchance rates. Ethereum on the other hand wants to introduce the rather nebulous concept of 'proof of stake', under which something like you say might be feasable.

aqsheehy• 9 years ago

That's not how bitcoin works right now. To change the network to function like that would almost certainly require a hard fork. That's probably enough to go on if you're genuinely interested in this.

thinkloop2• 9 years ago

There are 3 groups that have influence over Bitcoin:

- miners: they bear the biggest costs and are responsible for the security of the network. Without miners there would be no bitcoin.

- economic nodes: nodes that have real activity going through them that relay transactions and accept or reject blocks that miners provide them. Coinbase's nodes are significantly more valuable than my personal node for my wallet.

- core dev team: their power is soft but integral, no-one wants a chain that can't be updated over time.

Owners of coins currently have little to no influence.

rmc2• 9 years ago

Without miners there would be no bitcoin.

If all/lots of the miners pulled out, then wouldn't the work factor decrease so that regular people could run it on their desktop machines? That is what happened at the start of bitcoin, right? Are miners that required?

wyldfire2• 9 years ago

This concept is similar to Proof of Stake which was pioneered by Peercoin. [1]

It's been around a long time and bitcoin hasn't been changed to take advantage of it.

Ultimately, the community seems to have a big say in bitcoin and it's not limited to a proportional share. The community includes at least {holders, merchants, miners}. It's in their mutual interest to preserve stability but if one group acts in their exclusive interest to the detriment of the others, it makes sense for the others to consider a fork.

I was wondering, why the bitcoin owners themself cant't decide. ... should have more to say about it.

Ultimately that sounds a little aristocratic and bitcoin itself seems more egalitarian. Regardless of philosophy, the blockchain is defined to be a consensus of a set of computers running software. Anyone of us could write new software to take the bitcoin blockchain into a new direction with new features. If we could convince some folks to run our new software, we would have our own fork. If the features are compelling enough, we could take the majority of nodes with us. Decentralized and fairly democratic -- you can have your blockchain and we can have ours.

[1] https://en.bitcoin.it/wiki/Proof_of_Stake

nullc3• 9 years ago

It's been around a long time and bitcoin hasn't been changed to take advantage of it.

Of course it hasn't, Bitcoin is decentralized and Peercoin requires the developer of the system to continually sign the chain.

Proof of stake sounds lovely, but it doesn't work and attempts to rescue it have at best resulted in things with very different security assumptions and properties from Bitcoin. https://download.wpsoftware.net/bitcoin/pos.pdf

torrent-of-ions• 9 years ago

The layout of this page is strange. My browser window isn't wide enough to display four boxes in a row, so it displays three in one row, and then a fourth in its own row but at full width. At first glance I thought there was something different about the fourth box, but it should be with the other three.

barrkel• 9 years ago

There's only width for two rows of two boxes each on my viewport.

I keep my browser viewport in a portrait aspect ratio for readability and usability. Few websites look good or are easy to read in a maximized browser window.

mbloom1915• 9 years ago

xbt.eu much better monitor

corobo• 9 years ago

Is there a resource out there that explains all of this simply? Is this something like a computer network split brain situation?

appleflaxen• 9 years ago

the ownership of cryptocurrency is based on a cryptographically signed ledger. Today, everybody agrees who owns which bitcoin because everyone agrees on the rules of transfer.

When you change the rules of transfer in a subset of nodes/users, then all of a sudden there is disagreement about who owns what: there are two ledgers, and you look at the one whose opinion about "ownership" you agree with.

So the "fork" is a fork in ownership or truth: a difference of opinion about who owns what. Nothing more, nothing less.

But it's a complicated economic effect to predict, because it's likely that the losing side (the opinion with the smaller number of nodes supporting it) will wither and die - one major value proposition of bitcoin is that it's universal. But what happens to the people who used that losing fork in the interim? Well, basically none of their transactions were "real" (they didn't take place on the ledger that eventually won), and if you sold something to someone on that ledger, then they have the goods/services, and you have nothing.

splitbrain3• 9 years ago

So, as long as I hold on to the bitcoins I bought before all this madness started I should be safe? Like when in a few years some fork is the declared winner, I can still just sell my bitcoins on that winner network? (assuming bitcoins will be worth anything after those shenanigans).

jcahill2• 9 years ago

try this infographic: https://i.imgur.com/RjTkcdQ.png

jstanley2• 9 years ago

That's a little misleading because it makes it look like each decision point is a chain split.

This one is better: https://media.coindesk.com/uploads/2017/07/Screen-Shot-2017-...

technofire• 9 years ago

O'Reilly just published an updated edition of their bestseller on Bitcoin technology, "Mastering Bitcoin," earlier this month.[1]

For a more general/conceptual understanding of blockchain technology and its applications, including non-cryptocurrency applications, "Blockchain Revolution" is a good read.[2]

[1] Mastering Bitcoin http://amzn.to/2uewdK9

[2] Blockchain Revolution http://amzn.to/2vniXSf

baalimago• 9 years ago

might be very useful in handling valuable documents which can't get lost

randyrand• 9 years ago

Is it correct to say that if you have BTC pre-fork, then you can spend it twice post-fork? Once on each fork?

collinmanderson• 9 years ago

Or will the value halve after the split?

Obi_Juan_Kenobi• 9 years ago

Yes, anything in place before the fork will be recognized by both chains. You can then make transactions on either chain, and the other will go on as if nothing has changed, still recognizing the coins in their original address.

Realistically, the total value of these coins may change or it may not. One chain will likely dominate and have most of the value. But the total value may increase, decrease, or (unlikely) stay the same.

Total value could decrease if e.g. people feel that the fork demonstrates a weakness in cryptos. It could increase if the disagreeing parties are both satisfied with their forked chains and both have utility.

Bitcoin Fork Monitor

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