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Comment by tinus_hn | Hacker News Reader

How are these miner going to fiddle with the code on your computer?

That is not the issue caused by this concentration of mining power.

If those 50 people start playing by different rules, the sum of the value of the two resulting currencies will probably be less than that of BTC as it stands now.

No, if they start to play with different rules their mined blocks will be refused by everyone on the network and be worthless. That’s not what the issue is with concentrated mining power.

If they start to play with different rules, one of the hard fork remaining branches (or both) will be refused by everyone on the network and be worthless.

There's no telling whether it'd be the "hijacked" branch or the original one - assuming they control 50%+ of the mining power, there's a decent argument that the remaining miners would follow their lead if only to stay on the largest branch.

Developers of the core protocol would notice, add a flag and then miners/clients/exchanges who want to remain with the same dev team can signal they want to follow the "dev" chain instead of the "miner" chain.

Usually forks have checkpoints as well so things can't change willy-nilly.

If blocks in the "miner" chain break the rules of the "dev" chain, then no flag is required. You'll automatically stick with the chain that contains valid blocks, as determined by the implementation that you're running.

What miners do is irrelevant: the code known as bitcoin, with a 21M hard cap, simply will reject any block that creates more than its allowed bitcoins as invalid, the same way it rejects a random string of bytes as invalid.

Depending on your definitions this might or might no be true but it also might be totally irrelevant.

There is a protocol and system specification. There are implementations of that specifications. There is a distributed system running those implementations. And the distributed system has a state. Each of those can change and each of those or a combination of them could arguably be called Bitcoin.

If everyone would run new implementations with a different coin cap, you can argue that it is no longer Bitcoin because Bitcoin is a very specific specification with a 21M coin cap, but this would have little bearing on the actual situation.

The point is you need the economic majority to be on side in order to succeed with a hard fork. Just the top 50 miners switching on their own isn't enough.

Add 50 more - to reduce hash rate even more. Announce hard fork right after difficulty adjustment. And then, suddenly, these who have not forked will be stalled for several weeks. Instead of 10 minutes per block, the time will be 30 minutes and possibly more. And to adjust the difficulty those who have not forked would need... a hard fork?

Yes, these 100 miners are pools. But where pool participants will go then? Will pools who have not forked keep pool participation fees low?

Etc.

The game here is not quite simple. It is much more complex than appears at first sight.

The difficulty adjusts automatically. Bitcoin wouldn’t have come this far if it were that fragile.

It doesn't adjust immediately though. If a large majority of miner suddenly disappears then the block mining rate does indeed drop until the next difficulty adjustment.

So if 50% of the mining power left the next block would take on average about 20 minutes. Where it routinely takes about that long, because that’s just the way statistics work. A non issue.

Here’s a graph of the time blocks took over the last three years:

https://bitinfocharts.com/comparison/bitcoin-confirmationtim...

Look at the peaks and try to remember the issues that resulted in.

First, 20 minutes in average for power-distributed time-to-block would result in much, much higher peaks. In your chart I see 25 minutes for a block, then it will be 50 minutes.

Second, instead of two weeks to hash rate adjustment, it will take four weeks.

And if these staying with this slow bitcoin would decide to leave to more profitable currencies (not necessarily Bitcoin, there are other SHA256-based PoW schemes), that will push hash rate adjustment even further into future.

These 25 minute peaks were caused by a similar event, witness the also slow rates in the surrounding blocks. So that’s approximately how bad it would get in this ‘disastrous’ event.

https://www.cnbc.com/2021/07/03/bitcoin-mining-difficulty-dr...

We survived.

This is like saying because some people own the majority of printing presses, money is worthless.

Money has worth because people accept it in exchange for goods and services.

Bitcoin has worth because people accept it in exchange for goods and services.

It’s not the miners that create value, it’s the merchants. If miners start some fork they’ll leave the main blockchain, which will run fine without them. And they have absolutely no way of forcing anyone to use their fork. Only if the merchants start accepting coins from the forked blockchain will it become valuable. But that’s up to the merchants, not the miners.

There are problems with one miner controlling over 50% of the mining power. This is not such a problem.

Cryptoheads really gone from "printed money is becoming worthless, we need currency with enforced scarcity" to "it's all arbitrary anyway".

It's been quite educational watching the whole cryptocurrency community re-invent economics 101 and find out the problem has never been technical, always been political.

In the sense that updating the code to do something else would make it “not Bitcoin”, sure. But I really don’t think this matters to much of anybody if the “OG Bitcoin” drops to zero and the hard fork with new behavior wins.

If they have the majority mining power they could equally well undermine the security of the original branch, rendering it worthless as well. Miners have interests, core developers have interests, bitcoin users have all kinds of interests, none of them on their own decides what will happen. Without miners there is no bitcoin, but neither is there without developers or without users. Would you feel safe having your savings stored in the original bitcoin fork, knowing there is a mining cartel that holds 50% mining power? Some users will accept reasonable changes that weere lobbied for by the miners, if that means they get to enjoy the security provided by the miners.

Does this mean if enough people don't like you, they can cancel your money?

> If those 50 people start playing by different rules, the sum of the value of the two resulting currencies will probably be less than that of BTC as it stands now.

This is less a criticism towards you @CompuHacker and more about how ill-informed reporters are (especially it's most vocal critics) about Bitcoin's history.

We already went through this during the USAF/Segwit war that went on for far too long if you were there and delayed so many other key features that we are only now catching up to. With the added caveat that Roger Veer (a VERY ignorant whale with influencer status) and Jihan (CEO at the time of Bitmain with a monopoly on ASIC miners and large hashing power on the network) decided to hi-jack Bitcoin for their own ends. There were other whales/high net worth entities, including Coinbase, but lets keep it simple for arguments sake.

In short, it didn't work and no one uses/used their fork (Bcash) because the end result was that Bitcoin's mainchain and it's features was valued far more than what whales and hashing power/devices. Furthermore, upon the fork people arbitraged the coin and dumped it in exchange for Bitcoin and Bcash has never recovered since. Showing that playing by the rules has it's incentives and is rewarded: rewarding consensus is one of Bitcoin's core features, and I wish more people would realize this is the ecosystem is far more conducive toward progress than abject discord.

What's even more amusing is that a core developer of Bitcoin Core decided to help patch some of Bcash's source code, showing that what you fear has actually already played out and proved why Bitcoin has already proven itself and has a the battle scars to prove it.

It's remarkable what has happened in this space in the last 12 years, and in my ideal World I think their would be more time spent on that and what it has taught us via empirical experimentation rather than just the price.

Sidenote: It's why the plot of the 51% attack on the series Silicon Valley only made sense to people who really have no idea how the network attack would actually play out on decentralized networks.

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