We can confirm that there was a successful 51% attack on Ethereum Classic • Hacker News Board

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

#251

Post by hinkley » Tue, Jan 08, 2019, 6:09 PM UTC

pryce wrote: post #55

orblivion wrote: post #11

Earlier quoted context omitted.

Being only somewhat familiar, I wonder this: Why don't clients have a simple rule against accepting changes to history that are more than one or two blocks old?

Other people have answered this from a more technical perspective. Philosophically, what the distributed blockchain is , is an agreement for adjudicating whose record (eg list of transactions) should be agreed on as "the valid one". If you already have a different, reliable external way of deciding this question, that is (arguably) conceding that you didn't need a distributed blockchain in the first place. EDIT: I've…

> I am among those who are quite skeptical of these many blockchain projects.

There's always dilution when an idea has been around long enough and I'm concerned about the copycats trying to use blockchain for other things.

If Raft is democracy, then blockchain is Might Makes Right. The guy with the biggest stick always wins. There is no actual vote. Everybody is an accomplice.

That doesn't sound like progress, that sounds like regression. A really big one.

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

#252

Post by arcticbull » Tue, Jan 08, 2019, 6:42 PM UTC

kordlessagain wrote: post #247

arcticbull wrote: post #187

Earlier quoted context omitted.

And then the governor of the central bank doesn't because they don't take their orders from the executive branch, because they're a private entity? That's actually the whole reason they're a private entity -- to separate monetary policy from politics. Them being a private entity was what Satoshi was mad about, and yet here it is, saving our asses. What if Satoshi was ... wrong about everything?

Ad hominem. It's an opinion that some "policy" is "saving our asses". BItcoin isn't undergoing a 51% attack, currently. You don't know Satoshi's identity. Private entities still practice consensus. Just because one can't inspect or participate in the consensus doesn't mean it doesn't exist.

That’s all irrelevant to my point; I didn’t say bitcoin was being attacked. The “saving our asses” comment was that if the executive branch telling the fed how to monetary policy represents an attack then the private nature of the federal reserve represents a defense, one that’s working, or colloquially “saving our asses.” This effective structure is one bitcoin maximalists decry, and yet, it continues to work effectively. Further it’s not a stretch to attach that idea to Satoshi given the content of the genesis block. It’s not an ad hominem attack to suggest someone is wrong — even that someone’s entire thesis is wrong — the definition is to attack the attributes of someone instead of their argument, I’m refuting their argument.

It doesn’t matter who Satoshi is, I don’t need to know to opine on their ideas. That private entities practice consensus is fine (after all isn’t that just any human interaction?) and further I have no problem with consensus just the sheer wastefulness and intentional anti-efficiency of bitcoin as-is, the fact it’s waste isn’t sufficient to prevent an attack, it’s fiscal policy (inflation is fine, you’re not supposed to hold currencies) and the idea that somehow bitcoins dreadful wealth inequality will save us from the present dreadful wealth inequality. Not to mention the idea we should just defer monetary policy to a bunch of developers who hack on protocol instead of a group of trained economists. Or the idea of scarcity when anyone can and does fork coins to double the number outstanding every few weeks. Or it’s user hostility. Or it’s defenselessness to market manipulation. History won’t look kindly on this mess in a few years.

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

#253

Post by root_axis » Tue, Jan 08, 2019, 7:13 PM UTC

Klathmon wrote: post #100

root_axis wrote: post #87

Earlier quoted context omitted.

Nobody wants to back up their money. Just use a bank and never worry about it.

Like how nobody wants to have their accounts frozen with no notice? Or how people don't want a private company to be able to dictate what they are allowed to buy and sell? Or how people don't want to have to be constantly vigilant to ensure their simple 16 digit number doesn't get into the wrong hands (or that the hands they are required to give it to don't misuse it) and if/when it does they quickly report it to the…

> Like how nobody wants to have their accounts frozen with no notice?

This is not a concern for 99% of people. Nobody is getting their bank accounts frozen except for high profile criminals.

> Or how people don't want a private company to be able to dictate what they are allowed to buy and sell

Another fake problem. 99% of people can buy and sell whatever they want. There is a very very small intersection between what is legal and prohibited by the banks. Once again, this is only a use-case for criminals.

> don't want to have to be constantly vigilant to ensure their simple 16 digit number doesn't get into the wrong hands

Do you not see the irony in complaining about vigilance over a credit card number in a response about the work of having to back up your bank cryptocurrency private key? If your 16 digit card number is stolen just cancel the card and any fraudulent purchases will be remedied. Crpyocurrency is clearly worse in this comparison.

> All money systems have tradeoffs, cryptocurrencies are just another option

Cryptocurrency is not a "money system" with "trade offs", it's a hamstrung toy that facilitates some dark-market commerce and that's about it, it is otherwise demonstrably useless and certainly not an alternative for the incumbent financial system.

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

#254

Post by koheripbal » Tue, Jan 08, 2019, 7:42 PM UTC

garmaine wrote: post #186

drb91 wrote: post #173

Earlier quoted context omitted.

What would failure look like?

A system that has effectively bifurcated with conflicting chain tips caused by rewriting history with new nodes unable to tell which is original, or a fully centralized stake-mining where a subset of stake voters game the system to unfairly select themselves out of proportion of their stake weight.

Is that reeealy so different from a PoW fork?

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

#255

Post by Klathmon » Tue, Jan 08, 2019, 8:16 PM UTC

root_axis wrote: post #253

Klathmon wrote: post #100

Earlier quoted context omitted.

Like how nobody wants to have their accounts frozen with no notice? Or how people don't want a private company to be able to dictate what they are allowed to buy and sell? Or how people don't want to have to be constantly vigilant to ensure their simple 16 digit number doesn't get into the wrong hands (or that the hands they are required to give it to don't misuse it) and if/when it does they quickly report it to the…

> Like how nobody wants to have their accounts frozen with no notice? This is not a concern for 99% of people. Nobody is getting their bank accounts frozen except for high profile criminals. > Or how people don't want a private company to be able to dictate what they are allowed to buy and sell Another fake problem. 99% of people can buy and sell whatever they want. There is a very very small intersection between wha…

>This is not a concern for 99% of people. Nobody is getting their bank accounts frozen except for high profile criminals.

I've had my credit cards frozen multiple times because I did something their fraud detection deemed shady. One time I was stuck in another country without any way to pay for things! Yes, I now know that I have to warn my credit card company where i'm going or they may turn my card off again on me, and I now know that I should bring cash with me (at the time I didn't have a ton of money to be able to take a bunch out in cash to carry around, not to mention that it would have cost me tens of dollars to withdraw all of my own money, and the bank can still deny me making it in one big withdraw!), but that is again a lot of work to have to do and worry about just to be able to spend my own money.

(Also, the whole premise there kind of freaks me out. You need to warn the bank where you are going, and then if they approve you are allowed to spend your money there, otherwise you could be stuck somewhere with no recourse... That's terrifying!)

>Another fake problem. 99% of people can buy and sell whatever they want.

And yet finding credit card processors for porn and other adult things is extremely difficult for most companies in that area. Not to mention that your agreement with your credit card company prohibits you from buying a lot of that stuff (porn, sex, donations to politically unfriendly sites like wikileaks, etc...)

And go ask a marijuana shop why they don't take credit cards, and how difficult it is for them to handle money and even pay their employees because they can't get a bank account in the US. How they need to hire armed guards because they have to work entirely via bundles of cash because of the blacklisting of their industry.

Hell, just LAST WEEK there was an article at the top of this very website about how Paypal banned a company and is holding their funds for 180 days. And that thread is FILLED with other examples not just from Paypal but other companies as well.

https://news.ycombinator.com/item?id=18783493

You can say it's unlikely, but you can't say it's a "fake problem".

>Do you not see the irony in complaining about vigilance over a credit card number in a response about the work of having to back up your bank cryptocurrency private key?

No, because you never have to give out your private key, but you do have to give out and protect your credit card number.

>If your 16 digit card number is stolen just cancel the card and any fraudulent purchases will be remedied.

Unless you waited too long to tell them, or they say you've disputed too many fraudulent purchases on your account, or they mess up the paperwork, or they say the fraudster used your pin and they don't cover charges where a pin is used.

>Cryptocurrency is not a "money system" with "trade offs", it's a hamstrung toy that facilitates some dark-market commerce and that's about it, it is otherwise demonstrably useless and certainly not an alternative for the incumbent financial system.

It's clear you've made up your mind, I don't even know why I'm typing this out, you aren't going to change your feelings.

But I'm not asking you to believe me, I'm asking you to let some of us make different choices. You say 99% of people don't have a concern about these things, what about the 1% of us that do? What about the 1% who are being failed by current money systems, the 1% who have to rely on cash which is EXTREMELY susceptible to fire, theft, and loss because they can't back it up, the 1% who want to try and transact safely without a middleman in some situations, the 1% who think that there is still improvements that can be made in cryptocurrencies and are working toward solving problems with them so that one day they may become more useful to a much larger portion of people.

Also:

>certainly not an alternative for the incumbent financial system.

I never said it was an alternative in it's current form. I don't believe it is. No cryptocurrency at the moment is ready for widespread usage, and I don't believe it is going to ever take over the incumbent financial system ever. But that doesn't mean we can't try to make it easier to use, better, safer, expand the usable situations, experiment with cryptographic protocols, and maybe eventually some of that tech can make it into other money systems in some way to make things better for everyone. Or maybe it will just stay a fringe system for some who have been burned or blacklisted by the current system to use in some situations where they would otherwise be stuck.

You don't need to be involved, you don't even need to like it, but don't make up straw men and act like nobody out there wants some of the benefits of it because you personally don't.

I didn't want to get into fucking arguments about cryptocurrencies today, especially with someone who just decides that the problems it's solving for some are "fake problems" and handwaves them away, so this is the last time i'll reply here.

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

#256

Post by laverya » Tue, Jan 08, 2019, 8:56 PM UTC

samatman wrote: post #213

laverya wrote: post #177

Earlier quoted context omitted.

They don't need to get ahead by six blocks. They need to get ahead, with at least six blocks mined on the public chain. There's a massive difference there! The chain starts at block 1000, and you make a spend that will be included at block 1001 on the public chain. At the same time, you start mining your private chain from block 1000 (and you don't include that transaction in it). Now, the exchange you're using requi…

I take your point. We're saying the same thing, but I see now that this was unclear. The point of this sub-thread is that 51% doesn't give you a guarantee you'll mine faster than the 49%, just an edge, and that edge narrows as more blocks are required. A casino with a 1% house advantage would have days when it was in the red, around 178 of them in fact. By analogy, you need to line up six days in the black, in a row.…

And I'm saying that you're wrong there - the chance of getting more than half of the blocks approaches 1 as the number of blocks increases, given that you have 51% of the hashing power.

You're focused on the chance of getting 6 in a row. But what you should be looking at is the chance of getting at least 7 in 13, which is given by this equation:

P(K>=N) = sum(nCr(M, k) * p^k * (1-p)^(M-k)) from k=N to M

With M=13, N=7 and p=.51 - which works out to about 53%. But 8 in 15 also works, 9 in 17, etc. The limit of that probability (n+1 in 2n+1 as n -> inf) is 1.

Also, a casino is not likely to have many days in the red, just like it won't have many years in the red. (for bets only, ignoring everything else) This is because while the chance on any one bet may only be 51%, the chance of 10,000 bets, or 1,000,000 bets having a majority go south starts to get very, very small. (~27.5% for 1000 bets, ~2.5% for 10,000 bets at 51%, etc)

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

#257

Post by Robin_Message » Tue, Jan 08, 2019, 9:17 PM UTC

thaumasiotes wrote: post #234

Pyxl101 wrote: post #214

Earlier quoted context omitted.

What you're missing is the process by which new blocks are added onto an existing chain. Let's say that you take the "true" Bitcoin or ETC blockchain, if you want to think of it that way, and now multiple actors are proposing to add blocks onto it, potentially multiple blocks. Which one of those additions wins? The one that's the longest and has the most work behind it - that one wins. If you propose an addition that…

> When multiple branches exist on the blockchain, some consensus process has to reconcile which of them wins. That process is that miners select the longest chain. I've been arguing that this is a design mistake, and that the following selection algorithm would be superior: - Instead of selecting the longest chain, select the longest chain which does not alter any blocks which I, personally, consider permanent. Robin…

> guarantees that the ETH blockchain will be longer than the ETC blockchain.

Chain length is number of blocks, which is controlled by miners, not "laity".

I think your system might prevent double spends; unfortunately it would do so by rendering the network unusable for any new users, who wouldn't have a way to know which is the good network to join. I suppose a central authority could be used to identify the good chain, but most coins prefer not to have one of those.

The advantage of the simple chain length rule is that it is simple, requires no central authority, is self-correcting and the only weakness is a 51% attack.

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

#258

Post by thaumasiotes » Tue, Jan 08, 2019, 9:42 PM UTC

Robin_Message wrote: post #257

thaumasiotes wrote: post #234

Earlier quoted context omitted.

> When multiple branches exist on the blockchain, some consensus process has to reconcile which of them wins. That process is that miners select the longest chain. I've been arguing that this is a design mistake, and that the following selection algorithm would be superior: - Instead of selecting the longest chain, select the longest chain which does not alter any blocks which I, personally, consider permanent. Robin…

> guarantees that the ETH blockchain will be longer than the ETC blockchain. Chain length is number of blocks, which is controlled by miners, not "laity". I think your system might prevent double spends; unfortunately it would do so by rendering the network unusable for any new users, who wouldn't have a way to know which is the good network to join. I suppose a central authority could be used to identify the good ch…

> Chain length is number of blocks, which is controlled by miners, not "laity".

A block is a set of transactions, transfers of currency from one address to another address. Miners don't just add blocks because they're bored. They add blocks when someone submits a transaction.

So the number of transactions that occur is closely related to the number of blocks in the chain.

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

#259

Post by bouncycastle » Tue, Jan 08, 2019, 9:49 PM UTC

jki275 wrote: post #240

setr wrote: post #201

Earlier quoted context omitted.

As long as the attacker maintains 51%, he can eventually just repeat the attack, regardless of the number of forks.

You change the POW function in the fork to eliminate the attack.

Perhaps if the attack was done using ASICs, but when done with GPUs it can be repeated indefinitely. See discussion https://www.reddit.com/r/ethereum/comments/707h3b/can_anyone...

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

#260

Post by root_axis » Tue, Jan 08, 2019, 10:21 PM UTC

Klathmon wrote: post #255

root_axis wrote: post #253

Earlier quoted context omitted.

> Like how nobody wants to have their accounts frozen with no notice? This is not a concern for 99% of people. Nobody is getting their bank accounts frozen except for high profile criminals. > Or how people don't want a private company to be able to dictate what they are allowed to buy and sell Another fake problem. 99% of people can buy and sell whatever they want. There is a very very small intersection between wha…

>This is not a concern for 99% of people. Nobody is getting their bank accounts frozen except for high profile criminals. I've had my credit cards frozen multiple times because I did something their fraud detection deemed shady. One time I was stuck in another country without any way to pay for things! Yes, I now know that I have to warn my credit card company where i'm going or they may turn my card off again on me,…

> I've had my credit cards frozen multiple times because I did something their fraud detection deemed shady

A frozen credit card is not a frozen bank account. Your money is still available in the bank. You can try to paint fraud protection as a negative but the vast majority of consumers disagree with you. Not a real issue.

> No, because you never have to give out your private key, but you do have to give out and protect your credit card number

You're moving the goalposts. Giving out a credit card does not require a user to be vigilant about security, they simply leverage the number when they need to make a purchase, no back ups or additional work required.

> It's clear you've made up your mind, I don't even know why I'm typing this out, you aren't going to change your feelings.

Not an argument. It's clear you've made up your mind, I don't even know why I'm typing this out blah blah blah. See how pointless that is?

> I'm asking you to let some of us make different choices

Nobody needs my permission to do anything. I can assert that cryptocurrencies are useless and you can ignore me if you like.

> What about the 1% who are being failed by current money systems

What about them? They can do whatever they want, I'm not trying to stop cryptocurrency enthusiasts from doing their thing, it doesn't mean I have to agree that its useful.

> Paypal banned a company

Paypal is a private company... what's your point? Coinbase bans people all the time for arbitrary use of their coins. Based on your logic here that means cryptocurrency is failure.

> marijuana shop

Marijuana is federally illegal. Using cryptocurrency doesn't solve any problems that cash doesn't already solve just fine. Cryptocurrency has literally zero advantages for these businesses.

> that one day they may become more useful

Yeah... when that actually happens you won't hear any arguments from me.

> You don't need to be involved, you don't even need to like it, but don't make up straw men and act like nobody out there wants some of the benefits of it because you personally don't.

Talk about a straw man. I never said "nobody out there wants some of the benefits" of cryptocurrency, I said THE VAST MAJORITY of people don't want it, which is absolutely true and something you've already understood based on your response, so I am not sure why you have decided to pull up a starwman argument even though you already responded to my actual argument regarding the "1% who are being failed by current money systems".

> I didn't want to get into fucking arguments about cryptocurrencies today, especially with someone who just decides that the problems it's solving for some are "fake problems" and handwaves them away, so this is the last time i'll reply here.

This is a silly rhetorical trick. You drop a gigantic wall of text and then sign it with a complaint that you don't want to get in an argument and use that as an excuse to avoid responding to criticism. I didn't do any handwaving, I gave detailed specific responses explaining my position, but if regarding my argument as "handwaving" makes it easier for you to ignore it, by all means.