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We can confirm that there was a successful 51% attack on Ethereum Classic

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Re: We can confirm that there was a successful 51% attack on Ethereum Classic

#71

Post by Klathmon »

theamk wrote: post #54
albertgoeswoof wrote: post #29

Earlier quoted context omitted.

There are some cool things you can do with blockchains, they’re just a little over hyped. It’s pretty neat to send funds to someone without going via a 3rd party, it’s cool to run code on a global computer, it’s awesome to have digital assets that can’t be doled out on a whim by a central authority.

... It's great when you can lose lots of money by spilling soda on your computer?* *more money than this computer's price

can we not do this here please?

Nobody wants that, nobody is saying they want that, there are mitigations against that (like backups), and it's a stupid straw man that's not even trying to engage in a meaningful conversation on the topic.

Re: We can confirm that there was a successful 51% attack on Ethereum Classic

#72

Post by zanny »

hacker_9 wrote: post #3

Amazing, this blockchain technology really just keeps on giving. I have to say, it's quite entertaining to watch. It's pretty much a car crash happening in slow motion at this point. At least it provides something else to nerd joke about by the watercooler that isn't brexit for once.

It will be crashing when the market caps start retracing previous years. Its still ridiculously high to what it was in 2016 or any year before that. We have a good five years of "evidence" to the get rich quick scheme that attracts money into crypto so a lot of ignorant naive people will keep slowly coming in to find their money lost.

Re: We can confirm that there was a successful 51% attack on Ethereum Classic

#73

Post by aidenn0 »

nostrademons wrote: post #67
hacker_9 wrote: post #3

Amazing, this blockchain technology really just keeps on giving. I have to say, it's quite entertaining to watch. It's pretty much a car crash happening in slow motion at this point. At least it provides something else to nerd joke about by the watercooler that isn't brexit for once.

That's what it was like in 2016. I remember seeing the headline for the DAO hack on HN back then and thinking "Wow, good thing I didn't invest in this Ethereum thing". Someone had told me about it in 2015, I took a quick glance and passed thinking "Looks like a scam." Then 2017 happened and the joke was on me. Then 2018 happened and the joke was on them again. New technologies are always shitshows when they get start…

I had the XP service pack burned to a CD (or maybe DVD?) because on my college campus Code Red would infect a computer on install faster than you could download the patches.

Re: We can confirm that there was a successful 51% attack on Ethereum Classic

#74

Post by IncRnd »

brianwawok wrote: post #23
NathanCH wrote: post #18

Earlier quoted context omitted.

Some of these numbers are very low. $30/h for Bitcoin Private? Seems inexpensive, what am I missing?

No one uses it. So you attack it. Cool. You can't turn it into USD or anything else, so you just spend $30 for nothing.

And, that's exactly why it only costs $30.

Re: We can confirm that there was a successful 51% attack on Ethereum Classic

#75

Post by tgsovlerkhgsel »

danra wrote: post #65
johndunne wrote: post #7

This is inevitable. Ethereum Classic (ETC) isn't the only currency such attacks have been successful on. The site https://www.crypto51.app/ puts the cost of running a 51% attack on ETC at ~$5k per hour. The incentive for running these attacks for profit becomes higher as the market cap of these coins increases, making long-term 'investment' in these coins nonsensical.

Really surprised by the relatively low cost of attacking Bitcoin with 51% for one hour - claimed to be about $300k. Is this number for real? I can think of many actors for whom this is just small change, and who might have incentive to break trust in the Bitcoin network by successfully performing such an attack.

I believe the number assumes that you can get hashpower at the current price for (a small amount of) hashpower. However, as demand increases, the price goes up, making the attack more expensive in practice. Also, if people notice what you're doing, they'll probably stop selling hashpower to you (since you're attacking what makes their hardware valuable), driving your costs up further.

Re: We can confirm that there was a successful 51% attack on Ethereum Classic

#76

Post by chrisseaton »

CydeWeys wrote: post #43
semi-extrinsic wrote: post #22

Earlier quoted context omitted.

How can there be coins with $5M+ market cap where the cost of a 51% attack is $3.00 ?? In an efficient market, thieves should just immediately attack that. Or is the benefit too low?

Because the market cap isn't truly $5M. That figure uses the naive calculation of "whatever coins sold for most recently times the total number of outstanding coins". But if you tried to sell some significant fraction of the outstanding coins then the sale price would plummet, and you'd never actually reach $5M total. The actual depth of the order book at any given moment isn't close to $5M, plus a lot of outstanding…

> Because the market cap isn't truly $5M. That figure uses the naive calculation of "whatever coins sold for most recently times the total number of outstanding coins".

Isn't that literally the definition of market capitalisation?

Re: We can confirm that there was a successful 51% attack on Ethereum Classic

#77

Post by AgentME »

orblivion wrote: post #52
makomk wrote: post #33

Earlier quoted context omitted.

In short, because they don't know that the chain they saw first is the chain that other nodes saw first (especially if they weren't online at the time). At least in theory, an attacker can exploit this to permanently fork the chain.

Hmm. The humans at the exchanges seem to be able to tell the difference. I wonder if it could be encoded.

The "legitimate" fork can only be identified if you were online when the 51% attack started. Users who have started up their ETC client after the attack started will just see two forks and will pick the one with more blocks (which will be the 51% attacker's fork). No one wants a permanent fork, so the clients that were online the whole time disregard their knowledge of the previous "legitimate" fork and adopt the attacker's fork because it has more work and because that's the one everyone else is using.

Also, if you have clients follow the rule "never switch forks" to protect against 51% attacks, then any network partitions will cause a permanent fork.

Re: We can confirm that there was a successful 51% attack on Ethereum Classic

#78

Post by CydeWeys »

chrisseaton wrote: post #76
CydeWeys wrote: post #43

Earlier quoted context omitted.

Because the market cap isn't truly $5M. That figure uses the naive calculation of "whatever coins sold for most recently times the total number of outstanding coins". But if you tried to sell some significant fraction of the outstanding coins then the sale price would plummet, and you'd never actually reach $5M total. The actual depth of the order book at any given moment isn't close to $5M, plus a lot of outstanding…

> Because the market cap isn't truly $5M. That figure uses the naive calculation of "whatever coins sold for most recently times the total number of outstanding coins". Isn't that literally the definition of market capitalisation?

What works for companies doesn't work for cryptocurrencies. Companies have actual assets and cash flows, while cryptos do not. Companies are routinely acquired for a bonus above the total market cap (a premium on the share price times all shares outstanding). The same would never happen for cryptos.

A better analogy would be to calculate the "market cap" of gold.

Re: We can confirm that there was a successful 51% attack on Ethereum Classic

#80

Post by CydeWeys »

sp332 wrote: post #69
CydeWeys wrote: post #40

Earlier quoted context omitted.

If you're not on the largest coin for any particular interchangeable hashing algorithm then you're susceptible to these attacks, as people from a larger coin could simply turn their hardware against you and take you out. That means: For SHA256^2-specific hardware, Bitcoin (the real one, not Cash, Gold, or SV), for scrypt, Litecoin, and for anything mined on GPUs, Ethereum (not Classic).

people from a larger coin could simply turn their hardware against you and take you out. Only at the expense of leaving their coin more vulnerable to a similar attack.

Not if you're much larger than the alternatives, which tends to be the case.
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