[rschachte]

The statistical likelihood of a 51% attack happening on the blockchain seems statistically way less likely than a hack targeting our existing financial system.

I mean, it's pretty easy why blockchains are considered immutable, you can even code one from scratch in Python in less than 200 lines of code.

To control 51% of all those hashing power, an entity would need to power computers that works as much as that, along with paying for the equipment and energy consumption and whatever costs needed for the operation. Current estimates of Bitcoin mining energy usage stands at 71 TeraWatthour, enough to power the whole country of Austria.

[CamperBob2]

To control 51% of all those hashing power, an entity would need to power computers that works as much as that, along with paying for the equipment and energy consumption and whatever costs needed for the operation. Current estimates of Bitcoin mining energy usage stands at 71 TeraWatthour, enough to power the whole country of Austria.

Or they'd need to find a way to break SHA256. That's a risk you don't hear much about.

[rschachte]

yah, I have actually thought about this. Tbf, I'm not advocating strongly for or against blockchain. I'm just keeping an open mind in the same way when web 1.0 was being developed and researched.

I think it's fairly destructive to just discount new technology based on feeling. It really is a fun technology to learn and the more minds like we see on HN that research the topic, the more likelihood we will have in expanding the usefulness and security of blockchain use-cases.

[runarberg]

No, but you can discount the technology based on it’s historical records compared to it’s promises. Web 1.0 promised to be a good system of exchanging documents which could refer to each other. It delivered that pretty nicely and later improved on it.

Bitcoin promised to be a decentralized alternative to fiat currency and failed when it couldn’t scale to be even a tiny fraction of the global transaction. When people tried to improve on the original proposal they also failed at the very same thing while inventing new problems in the mean time. As of yet the only realized potentials of the technology are scams (which were never promised—at least to my knowledge).

Compared to Web 1.0 I think it is pretty safe for you to discount the technology based on a history of scams and failure to realize promised potentials.

[Eddy_Viscosity2]

The OP's point was that 51% of miners could agree to a change, and in a system where there are very large players that might not involve that many people.

[philistine]

And it already happened a bunch of times. Bitcoin has been forked a bunch of times, and one could argue the fork that gave birth to Bitcoin Cash was a successful 51% attack on Bitcoin itself.

[philistine]

Let's say the world's banking is running on blockchain. The US Congress is basically a veto on world banking, and I don't see how blockchain technologies can change any of that. The US Congress can pass a law saying any US bank and anyone transacting with them must use a specific version of the blockchain code, decided by the Department of Commerce.

If it's illegal to transact with the US under a previous version of this hypothetical blockchain banking technology, that's your 51% right there.

How could blockchain allow legal banking institutions to refuse to follow the law?

[300bps]

It isn’t as expensive as you think to 51% attack various coins.

https://www.crypto51.app/

You only mentioned BTC but that’s just one coin. Several alt coins (with multi billion market caps) have had 51% attacks including ETC and BSV.

But anyway the original point was that it is literally wrong to say that blockchains are immutable. You didn’t address that point at all, so I guess you agree with it?