Bitcoin Unlimited Miners May Be Preparing a 51% Attack | Hacker News Reader

Bitcoin Unlimited Miners May Be Preparing a 51% Attack

bitcoinmagazine.com

13 pointsprostoalex23 comments

This is not an attack, this is just the miners working out a way to increase transaction throughput on the block chain. Maybe they will go with the Bitcoin Unlimited plan or maybe they will end up going in a different direction. We'll have to wait and see. They're not doing this to attack Bitcoin, that's ridiculous. They've spent millions of dollars investing in mining equipment and they will do everything in their power to keep the price of bitcoin high. Calling this an attack is just pure nonsense.

Nobody is calling Bitcoin Unlimited itself an attack. It's the measures they might take to prevent a fork that would be an attack. An attack on the fork.

Bitcoin Unlimited IS a fork, why would they try to prevent a fork? I don't understand what you're saying.

The entire basis of the article is wanting it to not be a fork. If they have a majority of miners, they are in theory able to set the rules for actual bitcoin.

This is old [divisive] news on a rapidly developing situation. Several mediating proposals have been put forward in the time since this was published:

http://moneyandstate.com/thoughts-on-segwit2mb/

https://thecontrol.co/a-bitcoin-compromise-45cd92739387

http://www.coindesk.com/purse-proposal-touts-extension-block...

EDIT: And the title is click-baity.

It's not an attack if the majority of miners decide to use a specific implementation. That's how bitcoin works.

Most of the time it's unanimously agreed to follow the majority of minors. Everything runs smoothly.

When that's not agreed, preventing a fork requires some way of blocking the non-majority miners. That is an attack, and not just 'how bitcoin works'. Bitcoin has no builtin way of handling such disputes.

Why would it not be agreed to follow the majority of the miners? That's literally the whole basis of the blockchain. The chain with the most work wins. If you don't like it then you can make your own fork, nobody is going to care or try to stop you.

Because the different chains are abiding by different rules. Software A sees both chains as valid, while software B only sees the shorter chain as valid. The result is a conflict that cannot be easily resolved.

It's a human consensus problem. (And don't say that only the original version of the bitcoin rules are valid, or that would mean that bitcoin actually disintegrated years ago.)

Agreement by that definition is not a necessary condition, only a possible scenario. Majority hashpower is the built in way of handling disputes.

As with most things Bitcoin: can someone please help explain this to me like I'm 5? I've read numerous articles, even a whole book, on Bitcoin, and I still struggle to wrangle all of the vocabulary and terms necessary to read through an article like this.

Is this a new Bitcoin about to form? Same thing? Are existing bitcoins in "danger"? I struggle to even think of valid questions for some of these topics, you'd think by now there'd have been an effort to make this stuff more easily digestible to common folk (and I'm a technical guy! this just whooshes right past me).

Bitcoin has reached a limit on how many transactions per second can be confirmed. There's lots of ideas for how to resolve this, but no consensus.

The author is suggestion that one way this might soon be resolved is if 51% of the mining power all choose one specific option, a change in the protocol, and just start mining coins like that's the option everyone has agreed with. So long as you control most of the mining power, you can do that.

Now, this doesn't mean 51% of people- just 51% of the current processing power confirming Bitcoin transactions. And just for as long as it takes for everyone else to follow your lead. Once a couple big players give in, the rest will follow quicky.

Think of a git repo with all of the miners maintaining the master branch. If suddenly a majority of miners wants to create a new branch and they are over 51% of the miners, the new branch becomes the master branch.

Both branches still work. All coins before the fork apply to both branches, however, after the fork,both branches are different, any new coins purchased apply to only one branch.

It's essentially two coins at that point. Then essentially it's up to the payment processers like coinbase to decide which one to support.

That doesn't explain what the divide is about(How to scale Bitcoin now that it has become so much more popular) and doesn't touch on the fact that as Bitcoin is still achieving internality, and most users don't hold their own Bitcoin the exchanges/wallets and the interface fiat-liquidity they provide matter A LOT and these parties largely support seg-wit which arguably gives them more power.

Segwit is still compatible with increasing the block size a la Bitcoin Unlimited. They are not being forced to give up segwit here. It's really two separate conversations. Supporting segwit doesn't mean automatically opposing BU.

https://news.ycombinator.com/item?id=14047294

So is there a danger that I may have Bitcoins from the wrong branch after the fork? How can I tell?

You'd still have the coins on both branches. However, what is likely to happen is that the value of the coins on one branch will fall to zero once a consensus is reached about which branch to use.

Existing bitcoins are not in danger.

This is the primary confidence the market has amongst any of these perpetual emergencies, acquire all the bitcoin you want and ignore it.

When you want to transact on the bitcoin network, moving bitcoin from one address to another, thats when you want to be aware of this stuff.

Current situation in numbers (see https://coin.dance/blocks):

* Bitcoin Unlimited (and compatible implementations): Raises protocol maximum from 1MB up to 32MB blocks. No hard-defined activation threshold, miners decided to use 75%. Current progress: ~38%

* SegWit: Raises protocol maximum via extension blocks up to ~2MB. Activation threshold: 95%. Current progress: ~32%

* Currently active chain. 1MB blocks. ~30% mined blocks to keep things as they are (don't care etc).

I wonder how can anyone expect Bitcoin to become popular, if things keep being that unstable...

6 day old news, already caused a dip in prices, but was rebounded by the next day. Trying to hit the price again by posting this on HN?

Downvoting without comment is like making a claim without evidence.

Reply on news.ycombinator.com