Bitcoin Forum

Been away from the community for a while and this new word 'fork' is being thrown around everywhere. Can someone please explain the gist of what a Bitcoin fork is to a technological idiot and what all the ruckus is about? Thanks.

something like this will happen https://bitcoin.org/en/alert/2013-03-11-chain-fork, basically just another path of the network, but in the end only one will be choosen

so don't be worried about it, everything is safe

http://en.wikipedia.org/wiki/Fork_%28software_development%29

imagine a literal fork. it stems from one root but splits into 3-4 independent branches which are isolated and have no intermediate connection. That is a fork - bitcoin form, github fork, you name it.

Some considerations about types of forks that you might want to read...

https://en.bitcoin.it/wiki/Hardfork
https://en.bitcoin.it/wiki/Softfork

If we're talking about a blockchain fork, in simpler terms it would mean that the blockchain 'splits'.

I see a lot of thread on bitcoin fork all of sudden, just wondering what will be the affects of this split in blockchain and does a normal user who doesn't mines really need to know about what a fork really is? Someone care to explain it in simpler terms.

A fork is when there are 2 blockchains running, because the difference of adoption of an update in the bitcoin core.
A very idiot is that let's say that in the Bitcoin core version 11, every transaction must be sent with a red loop on it.
Miners that don't like the idea of the red loop won't use it, so every transaction sent from a bitcoin v11 will be rejected, but miners who use the bitcoin core v11 will accept, and them a fork happens where 2 blockchains are splitten in the network.

That's other fork. “Fork” in Bitcoin means something else.

Well... Those questions are a bit harder to answer. It will depend on how a fork takes place. If for some reason people running a certain client are deemed to be running an incompatible blockchain then it would affect them. To avoid this as a bitcoin user all you have to do is keep up with client updates. If upgrading is crucial at some point I'm sure it'll be hard to miss.

Aside of that, there are many "ifs" about the recent revelations. If Gavin decides to publish a client that will hard fork the current blockchain, it's very much possible that for a period of time, two blockhains could be running at the same time. So while balances are the same on both at the start of the fork, it's also up to the miners. If miners/pools mine exclusively with bitcoin core/xt then one chain gets rejected. If both chains are kept alive however, earlier owners of bitocoins have coins spendable on both chains.

So it's up to each individual, you won't lose bitcoins if you're careful, but you'll have to be cautious about new updates, services you use etc.

It would be like having an altcoin called XT, that shares all your previous BTC. It's a bit of a mindfuck but that's exactly what it is. They may co-exist forever as long as some people are processing transactions. Other decentralized p2p projects have forked before, and of course one version ended up being the popular one, but the other one still exists, for example freenet.

It's a bit different with bitcoin though. If we think of bitcoins as tokens with a monetary value, there are some more issues with bitcoin's blockchain being forked than the ones any other p2p project would.

Given that coins owned prior to the fork will be spendable on both blockchains (able to spend them in one without changing the balance in the other after the fork), most likely that the value of the coins will be heavily affected. We'll have BTCs (coins owned prior to the fork, spendable in both blockchains), BTCxt (coins on the "Gavin fork") and BTCcl (Coins on the old 1MB block version). That's three types of coins for as long as both forks are sustained. (names are just examples)

People owning BTCs will be able to import their private keys in services or wallets using each blockchain and spend them separately. This brings up many possible scenarios. It's very likely that one chain will just day if we wait a little, but what if it doesn't? Will the big exchanges that will support both BTCxt and BTCcl? And the price? What about the price then?

It's very likely that we'll see a lot of panic if a fork is pushed by Gavin. There are so many possible outcomes that it's scary to even think about it.

A Bitcoin fork is like creating 2 space-time continuums (think Back to the Future movie). Each side of the fork will have a different version of reality, so you loose global consensus. It's a really bad thing when it happens.

 :o This sounds serious, so some people's coins will be stuck on older blockchain and others will be on the newer one?? Why exactly was this necessary? Was there anything wrong with the current blockchain? I mean why fix it if it isn't broken?


This is great, as it is some people were complaining that it is hard for common people to use bitcoins and now this will make things super hard. Fantastico!

So when exactly is this fork taking place?

No is a god thing. You have a choice. What would be with our world without choices? You think there would be any progress if there would be only one path about everything. Actually if there would not any Forking on Earth after genesis there would not be anything worth of mention here. Not that bunch of market manipulators want to buy some cheap Internet of money in upcoming days.

Sure makes things harder for people to understand. But don't worry, it's likely that a fork could never happen. It's all being discussed at the moment.

You can follow development discussions on SourceForge (http://sourceforge.net/p/bitcoin/mailman/) and maybe Reddit  (https://www.reddit.com/r/bitcoin)for important updates as.

Actually, it shouldn't make it much harder. The fork only occurs when >90% of the nodes on the network switch to the new version. If this doesn't happen, the the old version will still be used. By having almost all of the network use the new version, then consensus will be achieved and any business with large amounts of money or customers at stake will switch to the new version because that will be the one that is valid.

There is no official date yet, but it will likely occur sometime in early 2016 if all goes as planned.

Wrong, nothing about 90% is mentioned anywhere. One fork stops being active when no one runs it.
And by the way, Bitcoin-xt is out there ready to be downloaded. Just not running on a fork yet.

https://www.reddit.com/r/Bitcoin/comments/383jam/support_larger_blocks_by_running_a_bitcoin_xt/

Wrong. In order to fork the blockchain without seriously screwing everything up, the hard fork must occur when a super-majority of the blocks mined fit with the new version. This means that probably >95% of the last 1000 blocks mined must be the new version before the actual fork happens with the mining of a greater than 1MB block. It will happen similar to what happened with upgrading to block version 2, as described here: https://github.com/bitcoin/bips/blob/master/bip-0034.mediawiki except that it will be a hard fork instead of a soft fork.

So basically a) a fork will have to happen rather it is a month from now or a year and b) it only has negitive outcomes?  This is where I think bitcoin gets really confusing.   :-\

Of course you're confused. Where did you get that there are only negative outcomes? Clearly one decision is the right one. The problem is people don't agree on which one.

An unintended network fork that is not quickly addressed and resolved is pretty much the death of the coin.

Perhaps the OP is referring to a planned hard-fork, to introduce necessary changes that simply break the previous consensus logic. In that case of course it's a good thing.

Ok, I guess you're right that a fork ends when no one is running it.  But isn't it true that after the 90% (of blocks in the last 1000 are the new version) that the new version nodes stop accepting blocks which are the old version?  Ie, there is something about 90% mentioned somewhere, perhaps just not exactly as was said above---it's that 90% of the last 1000 blocks triggers rejection of old-style blocks by all nodes on the new software. I could be wrong.

Also, I thought I saw something about Gavin switching to developing on bitcoin_xt, was that right or was it just a threat or something?

I am really confused with all of this, I just hope that it doesn't happen anytime soon because a lot of people need to understand about its pros and cons and what exactly they need to do prepare for the fork, I was reading the discussion here True or False: If not enough people join 20MGCoin, we fork into Bitcoin and 20MGCoin [I'd then want Bitcoin] (http://www.reddit.com/r/Bitcoin/comments/385ulp/true_or_false_if_not_enough_people_join_20mgcoin/) and as far as I understand from it, if I have 2 bitcoins in my wallet, after the fork I will have 2 bitcoins on each blockchain?? but only one of it might have any value and the other will sink to the bottom of the ocean? But that is only if it is an even split, I don't think it'd be that even.

And does this mean that we would need new clients for the new blockchain?


What about people who are not aware of this and don't use Bitcoin Core?

Sorry if it is a dumb question, I am just trying to understand it's affects. Be gentle! :-[

That is not true. In order for the fork to happen a super-majority (meaning >95%) of the last 1000 blocks mined must abide by the new version rules and the old version rules. That means that those blocks have a new version number, but are still smaller than 1 MB. Only after the super-majority of the blocks is achieved will the blockchain hard fork with the creation of a block that is greater than 1 MB. The vast majority of the network will accept the new fork, the remaining minority will be left on a stale, insecure blockchain which pretty much no one will accept or use.

The other thing is that for the casual user, who doesn't mine and doesn't run a ful node, they'll basically be unaffected.  Their spv client will send a transaction the same as before, and their walet wil be parsing the prope blockchain as long as they stay on some reasonably update software.  I really don't think he casual user has to worry.  However, there's a lot of interesting discussion and learining to be done if you like finding out more.

Don't worry!  But knowledge is power.

Where's DannyHamilton when we need him?

He has all of us blocked for carrying the signature advertisement.  :'(

https://bitcointalk.org/index.php?topic=973843.0

I'm well aware of this, but still, he's not that active recently. Explaining the fork's theory would have been a time for him to shine.

https://bitcoin.org/en/developer-guide#block-height-and-forking

The Bitcoin developer guide has a section on forking.

He has explained it before, but people just don't understand. He must be as tired as everyone of this shit.