Without massive investments in ASIC's you have effectively zero influence. Until you have 51% of the hash power you can't make any changes as you simply get ignored unless you follow the exact same rules as the majority.

> Until you have 51% of the hash power you can't make any changes as you simply get ignored unless you follow the exact same rules as the majority

This is exactly their point. This applies to everyone and all organizational entities.

Well, "whoever is in power makes the rules" applies to everyone and all organizational entities, too. In this case, we're talking hash power, but same thing, isn't it?

A huge amount of hashpower was behind the desire for bitcoin cash, and that didn't work out.

Think some underestimate firstmover advantage and end-user inertia.

Actually, even with 51% of hashpower, you cannot force all the other nodes to forward or propagate your invalid blocks if you decide to start changing the rules.

This is a common misconception about bitcoin. Every single node on the network validates every single block, not just miners.

Thank you. I see this argument pop up on HN all the time and can't understand why it's so common. You'd think if a 51% attack were such a threat to Bitcoin it would have at least been attempted by now, after so many years.

Why do you think that?

Being able to fake blocks isn't significantly more useful than being able to double spend. I don't see why that would be the tipping point.

The reason you don't see these attacks is that they are difficult and very expensive and they would ruin the value of the coin so you can't even profit off it.

That is precisely my point

The point is not that you can set rules, it's that you can prevent other people from changing the rules without your consent, even if they are the majority.

You still have freedom to pick the rules to a small degree though - you choose which blockchain to use. Don't like bitcoin? Try bitcoin cash/ethereum/ethereum classic/litecoin/dogecoin/Monero/siacoin/decred/etc etc.

A common misconception is that miners can pick the rules, but they can't. They can only choose to enforce additional rules (which is powerful), they can't ever violate the original rules.

Wouldn't you be creating your own fork? A fork of one where peers would then reject every message from you?

No man is an island, unless he wants to completely devalue his bitcoin.

They wouldn’t reject messages from you so long as they are valid on their nodes.

Right and thus consensus exists. And that consensus consolidates to a single set of rules (and any major deviations result in forks).

A 51% plutocracy is still a form of state governance that qualifies as fiat money and effectively can destroy the value of your coins if you resist.

It is really no different than the government fining you for disobedience.

There are philosophical theoretical arguments against this, not pragmatic ones.

A 51% attack means a lot of bad things can happen to bitcoin. Its value would probably crash if an individual got 51% of the power just because it is no longer truly decentralized, even if they don't abuse that power.

Bitcoin was made with the idea that a 51% attack would be unlikely and unfeasible; as long as that holds, I'm not sure what value your comparison has. You might as well make a comparison to any other possible disaster. ("A solar flare is a form of state governance that will destroy the value of your coins...")

The top four pools have ~55% of the total hashing power. They could orchestrate a 51% attack with a conference call. As we've seen with the BTH/SegWit2X fiasco, Bitcoin is anything but democratic or decentralised. A cartel is every bit as dangerous as a monopoly.

And what exactly do you think a 51% attack can do? I'll tell you what: censor transactions and make double-spends.

Not exactly end of Bitcoin danger, is it?

If someone had unrestricted ability to double-spend, getting around any attempted countermeasures, they would be able to turn every exchange into a money printing machine. It's hard for me to see how it wouldn't be the end of Bitcoin.

> A 51% attack means a lot of bad things can happen to bitcoin. Its value would probably crash if an individual got 51% of the power just because it is no longer truly decentralized, even if they don't abuse that power.

That already has happened which is why people forked. You can live in denial of that fact if you wish but a minority "lost" the "vote" and forked Bitcoin.

http://fortune.com/2017/08/07/bitcoin-cash-bch-hard-fork-blo...

The BTH/SegWit2X fiasco shows Bitcoin isn't "more" decentralized than an oligopoly, an oligarchy, or a plutocracy.

> Bitcoin was made with the idea that a 51% attack would be unlikely and unfeasible; as long as that holds, I'm not sure what value your comparison has. You might as well make a comparison to any other possible disaster. ("A solar flare is a form of state governance that will destroy the value of your coins...")

The fact pro-bitcoin people swear up and down that isn't the case doesn't change the fact that they are effectively the Bitcoin state and that 2-3 of them + a number of smaller people can effectively "vote" to pass "laws" that are enforced against your BTC regardless of your wishes.

Simply because they don't outright steal your BTC doesn't change the fact you have to comply to retain the value of your BTC.

What does bitcoin cash have to do with a 51% attack? Forks are a different type of thing than 51% attacks.

Why would someone destroy all the value of their money and all the money power to mine just to troll?

Sure a government might do that, but they could point a gun to every full node owners head and tell them to stop it just like China did. It would also be much cheaper.

Step 1: purchase, borrow, or steal enough hash power to reach 51% for a short while

Step 2: use this power to force enough transactions to make yourself rich enough to keep 51% power indefinitely

Step 3: profit

51% hash power lets you doublespend coins. It does not let you steal from wallets or change the block reward rules.

Which is sufficient to allow you to do what I suggested. Spend coin once on paying for everything, and again on yourself to keep all the money to spend again later.

So you become like a government, able to print more currency at will?

According to this definition, is there any possible form of widely-used money that isn’t fiat money?

> According to this definition, is there any possible form of widely-used money that isn’t fiat money?

There used to be 100+ years ago such as gold and silver coins where if you were able to remove them from Country A to Country B, then Country A could no longer enforce such financial penalties against you. This is what many of the cryptocoins _wanted_ to be.

It needs to be a hard currency that leaves you immune to monetary policy and fines unless you are physically within the jurisdiction of the country.