Bitcoin Gold Hit by Double Spend Attack, Exchanges Lose Millions • Hacker News Board

Re: Bitcoin Gold Hit by Double Spend Attack, Exchanges Lose Millions

#481

Post by eric-hu » Thu, May 24, 2018, 12:57 PM UTC

djsumdog wrote: post #310

vntok wrote: post #167

Earlier quoted context omitted.

If Visa or SEPA got hacked over 12 hours and then fixed the root cause, would you stop using credit cards or bank transfers altogether? I would not.

Credit Card companies and banks can reverse the transactions, so long as they keep track of things in batches, have strong backup system for their ledgers. So long as they're not SWIFT transactions that leave the country, and the country that's attacked as a strong/regulated inter-bank transfer system. If a bank is critically hit so bad funds become impossible to correctly attribute to people (Fight Club type unreali…

> People wouldn't stop using banks, but they would stop using that bank.

I'd really like to live in a world where that's true, but I don't see Equifax going anywhere. PayPal does a form of this as well, except it's the central system and not a rogue actor that locks your money away. Well informed users avoid PayPal, but there appear to be many more uninformed users.

Re: Bitcoin Gold Hit by Double Spend Attack, Exchanges Lose Millions

#482

Post by DennisP » Thu, May 24, 2018, 1:03 PM UTC

cdetrio wrote: post #296

DennisP wrote: post #228

Earlier quoted context omitted.

Interesting points. A defense against this type of attack is to use at least the hybrid proof-of-stake design that Ethereum is rolling out in about three months; blocks are proposed by proof of work, but proof of stake periodically adds a layer of "economic finality." Here's a paper: https://arxiv.org/abs/1710.09437

51% attacks on the block proposal mechanism could prevent the PoS commitments from ever becoming finalized (i.e. violate liveness), though.

True, that's a risk it will still share with pure PoW. But at least you don't have to worry about doublespends after your transaction has finalized.

Full Casper may have stronger liveness guarantees eventually, I'm not sure. At a minimum it's easier to manually intervene to get the network going again. (You could also do that in PoW by changing the hash algorithm, but you can probably only pull it off once, migrating from ASIC to general purpose hardware.)

Re: Bitcoin Gold Hit by Double Spend Attack, Exchanges Lose Millions

#483

Post by Frondo » Thu, May 24, 2018, 1:16 PM UTC

hapnin wrote: post #368

wpietri wrote: post #346

Earlier quoted context omitted.

That's definitely not proof of real economic utility. How many bets happen in Las Vegas every day? But economically, they're negative-sum events exploiting cognitive weaknesses.

Use as a currency was the point I was addressing. Bitcoin has been a working network for 9 years with 300,000,000 plus transactions. It's a useful currency.

I wonder how many minutes it'd take for cash to manage 300 million transactions.

Re: Bitcoin Gold Hit by Double Spend Attack, Exchanges Lose Millions

#484

Post by sudomake » Thu, May 24, 2018, 1:16 PM UTC

h1d wrote: post #196

dragonwriter wrote: post #115

Earlier quoted context omitted.

Assuming you want to make money directly, sure. If you want to harm a community in which the currency is widely used, the incentives are different.

What kind of incentive does the attacker have to just harm a community of a distributed system?

Making GPU prices great again

Re: Bitcoin Gold Hit by Double Spend Attack, Exchanges Lose Millions

#485

Post by sudomake » Thu, May 24, 2018, 1:22 PM UTC

hapnin wrote: post #321

doorbumper wrote: post #176

Earlier quoted context omitted.

Bitcoin hasn't been useful as a currency for a long time. I don't think that's a good measure for determining how an event might affect bitcoin price.

Bitcoin averages something on the order of 200,000 transactions per day. It's useful to someone.

And Visa can do 7x that in a minute

Re: Bitcoin Gold Hit by Double Spend Attack, Exchanges Lose Millions

#486

Post by api » Thu, May 24, 2018, 1:22 PM UTC

spuz wrote: post #478

root_axis wrote: post #201

Earlier quoted context omitted.

Why is this argument repeated so often? How is that comparison not clearly absurd to you? The conventional financial system is very obviously many orders of magnitude more efficient than bitcoin.

How is it obvious that conventional financial transactions are orders of magnitude more efficient than bitcoin? You can't use transaction price as a metric because it reflects a lot more than just the energy consumption of the system and even if you did, conventional transactions are not orders of magnitude cheaper than bitcoin transactions.

Quibbled: conventional transactions are cheaper, but not "orders of magnitude."

Also Bitcoin is one of the slower block chain coins.

Re: Bitcoin Gold Hit by Double Spend Attack, Exchanges Lose Millions

#487

Post by sudomake » Thu, May 24, 2018, 1:29 PM UTC

cal5k wrote: post #381

biztos wrote: post #211

Earlier quoted context omitted.

I'm a bit ignorant about cryptocurrency, but doesn't "I pay cash for bitcoin" sort of prove the parent's point that it's not "the currency of the future?"

Sort of like how you pay USD for Euros when you’re on vacation?

USD,EURO,BTC

One of these is not like the others

Re: Bitcoin Gold Hit by Double Spend Attack, Exchanges Lose Millions

#488

Post by sudomake » Thu, May 24, 2018, 1:32 PM UTC

ggg9990 wrote: post #30

mike-cardwell wrote: post #12

Crypto currencies are worthless unless they have an enormous amount of hashing power behind them. We could really do with a webpage with a list of crypto currencies, the hashing power currently behind them, and how much it would cost somebody to take over 50% of the network. Or does that already exist?

Interesting point. The cryptocurrency energy consumption problem will never be solved, since if it is, it will be economically feasible to attack. So cryptocurrency adoption in the mainstream will require massive electricity consumption.

Yup, it anti-scales. If anything its scale resistant. Its a red queens race.

Re: Bitcoin Gold Hit by Double Spend Attack, Exchanges Lose Millions

#489

Post by optimuspaul » Thu, May 24, 2018, 1:41 PM UTC

cheschire wrote: post #422

dnautics wrote: post #387

Earlier quoted context omitted.

In practice, Airbnb has failed at its aim of providing airbed style accommodations for conference goers.

Airbnb is a service, where bitcoin is a commodity. I don't mean to imply you are wrong. I simply mean that there may be an even more interesting parallel out there where a commodity is no longer being used in its originally intended way which may support bitcoin's evolution of purpose.

How is bitcoin a commodity? I think you give it too much credit to elevate it to that status.

Re: Bitcoin Gold Hit by Double Spend Attack, Exchanges Lose Millions

#490

Post by lmkg » Thu, May 24, 2018, 1:46 PM UTC

dnautics wrote: post #387

wpietri wrote: post #343

Earlier quoted context omitted.

I think the split you draw between people looking at Bitcoin-the-real-thing and people adoring the machinery is an excellent one. If you look at the original paper, it's pretty clear that Bitcoin was meant to be peer-to-peer electronic cash: https://bitcoin.org/bitcoin.pdf In practice, it has failed at this aim. I don't think that was necessarily so; plenty of things start out rough and become more useful over time.…

In practice, Airbnb has failed at its aim of providing airbed style accommodations for conference goers.

Airbnb is a business. It's "aim" is to grow and make money.

Bitcoin was a political experiment before it was a technological one. You don't pivot political beliefs the way you pivot a business. The technological experiment is still ongoing, but the political experiment has failed its goals.