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Topic: The Biggest Flaw with Bitcoin that Could Crash the Entire System - page 2. (Read 5407 times)

legendary
Activity: 2912
Merit: 1060
Seriously people stop letting them scam you.
sr. member
Activity: 302
Merit: 250
I think it's necessary to highlight here: no miner can change the blockchain history or steal anyone's bitcoin even he has more than 51% of the hash rate. What he can do is only make several blocks mined recently become orphan. It means 1) he can try double spending, but not easy after enough number of confirmations. If there're too many confirmations, it takes long time for his fork to catch up. 2) he can block some accounts to make any transactions, but at a very high price. He has not make every block including that transaction orphan.

That's almost all he could do with more than 51% of hash rate.

True.  Double spending would probably be the most that would be accomplished, as well as orphaning a few blocks mined by others.  You can only double spend coins you own, so to even make a double spend worthwhile, you would already need to own a substantial amount if Bitcoin.  If you did own that amount of Bitcoin, you probably wouldn't want to upset its value.
legendary
Activity: 882
Merit: 1000
I think it's necessary to highlight here: no miner can change the blockchain history or steal anyone's bitcoin even he has more than 51% of the hash rate. What he can do is only make several blocks mined recently become orphan. It means 1) he can try double spending, but not easy after enough number of confirmations. If there're too many confirmations, it takes long time for his fork to catch up. 2) he can block some accounts to make any transactions, but at a very high price. He has to make every block including that transaction orphan.

That's almost all he could do with more than 51% of hash rate.
legendary
Activity: 1988
Merit: 1012
Beyond Imagination
Currently we are still in the period of large scale of ASIC devices roll out, after more ASIC manufacturers start to deliver, private mining pool's electricity and cooling capacity will quickly reach its limit
staff
Activity: 4284
Merit: 8808
Don't be so sure. What if someone gains 51% of the hash-power and steals all the top-100 wallets.
This isn't how Bitcoin works.

Bitcoin is first and foremost a trustless system predicated on autonomous validation. We presume our peers are _evil_ and we verify the rules for ourselves independently from what our peers claim.  After all, if we can't trust central banks and democratic governments to manage their fiat how could we possible trust a bunch of sketchy, anonymous, self-selecting miners?

Unfortunately, there is no way to autonomously validate _order_ in a decentralized system, so we use mining to decide on an order, but thats all. Ordering control is powerful, but no majority of miners— no matter how large— can just randomly rob wallets.  A miner that produces rule violating blocks is equivalent to a miner that has shut down: their blocks are nearly costlessly ignored by all nodes.

Strictly limiting the behavior of miners is part of what keeps their incentives aligned. As you note— if they could just selectively rob a few people, they might well get away with it. But fortunately the system can be— and is— built so that those sorts of attacks are simply not available to miners.


FWIW, the cited article falsely claims the quoted text was removed from the weaknesses page— it wasn't.  I really suggest ignoring "cryptocurrency news" it's a really spammy outfit.
donator
Activity: 1218
Merit: 1079
Gerald Davis
CPU-only mining that is botnet resistant and also limits the sizes of pools is very much needed.

So when can we expect that to appear?
Q1 2014

How could CPU mining be botnet resistent? What's different between a computer in botnet and a normal computer?


Memory.  The average botnet node is a 5-10 year old machine (most commonly Windows XP).   A memory requirement larger than the average memory of botnet node that also increases at the rate of Moore's law (or possibly below it as a margin of safety) would be highly resistant to botnets. 
full member
Activity: 140
Merit: 100
Mining FTW
Things to keep in mind,

Miners start moving away from pools start to reach close or on 50%..

Secondly, the bitcoin community never sleeps... You can try to pull off a 51% attack unnoticed, but depending on how quick you are you are fighting idealists... So if you wanna attack the network you gotta do it in quick succession, or these crazy guys will find so much hashing power... that you need to go back to production.

If you have near unlimited resources you can still pull of a 51% attack and attempt to destroy the network. But unless you want to destroy the network... a 51% attack is useless... Stealing other peoples coins, instantly makes all coins useless, attempting double spends same.

Keep in mind though that the bitcoin network is still rising with more than 20% hashing power per 2 weeks...

All this together means that you would need to pretent for a long time to be serious player in the industry, without getting caught. Even then the chances of you pulling it off... No-one knows...

Say someone was serious, and we saw a chunk of 45% unknown... knc, asic-miner, avalon, bfl they all aren't gonna risk that bitcoin goes to zero... They will turn on any hashing power they have in stock to compensate, maybe even delaying customer shipping. And the community will love them for it as they saved bitcoin. (good chance I still missed some mining companies)

So pulling off an attack now, has you fighting against those parties to start of with, then the idealists will start putting their GPU's back to bitcoin. (all alt-coins will see a big drop in hashing power)

So if you can beat all of this right now, you can pull it off. However a year from now, the market will be saturated with the latest gen ASICs, at which point I don't even see the US gov pull of a 51% attack, due to the sheer volume of hashing power needed. (you're going to be looking at millions of latest gen ASIC to pull of a 51% attack)

So all in all... not to worried... the gov's are still to busy with laughing... (some appear to be getting it, but looking at the history, they are just doing their old business... for example India)
By the time they realize... its going to be late to stop it.

Beyond government's, we don't have to fear many, as almost all humans or companies are motivated by money or ideology, the money incentive of bitcoin is easy, and as far as ideology goes most are fighting for freedom, which clearly lines up with bitcoin. (what's more free than being able to send money to anyone you want, without anyone being able to tell you no)

So yea, its FUD as always Sad
full member
Activity: 195
Merit: 100
No one will bother to gain 51%. The argument is simple. the 51% is the self-destruct button. They destroy the bitcoin system and they destroy themselves. Why sink the ship when they are onboard the ship?

Don't be so sure. What if someone gains 51% of the hash-power and steals all the top-100 wallets. Only a few dozen users are robbed, but 5 million coins will now be held by the attacker.

Selectively conducting transactions and reverses will not cause the death of Bitcoin.

Assuming ghash.io gains 51%, well... or maybe when they are reaching 45%, the whole bitcoin mining community will start protesting. If they don't lower but keep increasing their hashing power (and assuming gavin and his team cant do anything), the trust on bitcoin will be gone. This whole bubble will burst and all hardware and bitcoin will become worthless. Give them 10000 million bitcoins and they can't buy a can of coke. So keep increasing your power dude.

They will sink before they will have any chance of stealing people's wallet. In a way, the people still have the ultimate power to control the future of bitcoin - the beauty of it.

I can assure you that ghash.io already has the capability to reach 51%. With all the 2TH coming up... They have more than enough money to buy a dozen of them. Why aren't they doing it? because they are not stupid. I believe they are already decreasing their hashing power when they read this post.

legendary
Activity: 1148
Merit: 1008
If you want to walk on water, get out of the boat
No one will bother to gain 51%. The argument is simple. the 51% is the self-destruct button. They destroy the bitcoin system and they destroy themselves. Why sink the ship when they are onboard the ship?

Well, unless they are NSA.
Exactly, unless they are NSA, any government, any bank, any company wich don't want bitcoin... They have the perfect self-destruct button to fix the bitcoin problem.
sr. member
Activity: 266
Merit: 250
You should be very happy to keep seeing Ghash.io on blockchain.info.  What you should be scared about is when you suddenly STOP seeing them and block times drop down to 5 minutes for a few days.  *That's* when you worry they might be mining a side-chain for a 51% attack.

You mean like right now since yesterday ??

Ghash has silently gone from 33% to 28% today, meanwhile the Unknowns have gone from 18% to 23%....................................................

https://blockchain.info/pools?timespan=24hrs

I've been following Ghash since the double spend. I dislike them more by the minute.

Is it known who the owners are? Are they and Cex the same thing or are they partners as they claim?
legendary
Activity: 2912
Merit: 6403
Blackjack.fun
The biggest piece of  FUD that has been ever posted...

There were moments in the past when pools were far closer to 51% , and they even got over that. Nothing happened.
Why?
Because there is nobody insane enough to kill their own business.
You don't kill the f golden goose.

hero member
Activity: 793
Merit: 1026
You should be very happy to keep seeing Ghash.io on blockchain.info.  What you should be scared about is when you suddenly STOP seeing them and block times drop down to 5 minutes for a few days.  *That's* when you worry they might be mining a side-chain for a 51% attack.
hero member
Activity: 518
Merit: 521
CPU-only mining that is botnet resistant and also limits the sizes of pools is very much needed.

So when can we expect that to appear?
Q1 2014

Very unlikely. to my knowledge it is not even known in principle how that should work. one problem I think that botnet resistance and ASIC resistance are contrary goals.

"Any sufficiently advanced technology is indistinguishable from magic"-- Arthur C. Clarke.
member
Activity: 70
Merit: 10
CPU-only mining that is botnet resistant and also limits the sizes of pools is very much needed.

So when can we expect that to appear?
Q1 2014

Very unlikely. to my knowledge it is not even known in principle how that should work. one problem I think that botnet resistance and ASIC resistance are contrary goals.
legendary
Activity: 3766
Merit: 1217
No one will bother to gain 51%. The argument is simple. the 51% is the self-destruct button. They destroy the bitcoin system and they destroy themselves. Why sink the ship when they are onboard the ship?

Don't be so sure. What if someone gains 51% of the hash-power and steals all the top-100 wallets. Only a few dozen users are robbed, but 5 million coins will now be held by the attacker.

Selectively conducting transactions and reverses will not cause the death of Bitcoin.
hero member
Activity: 518
Merit: 521
CPU-only mining that is botnet resistant and also limits the sizes of pools is very much needed.

What are you thought on "memory coin 2.0"? It fits the agenda?

I provided my technical opinion. As far as I can see, it is not ASIC-resistant. It is probably GPU-resistant.

CPU-only mining that is botnet resistant and also limits the sizes of pools is very much needed.

So when can we expect that to appear?
Q1 2014

How could CPU mining be botnet resistent? What's different between a computer in botnet and a normal computer?


Require more than 8 GB of memory which eliminates 80 - 90% of the bots. And cause the computer to slow to a crawl swapping virtual memory to hard disk (thus alerting those high end gamers that their computer has a virus) for any other activity that required access to memory if most of the memory was in use by the hash.

the pool op over at ghash.io is making mad money every single day.

With zero fees (allegedly, not sure if true), and paying out tx fees, just how is he making mad money on his pool?

If someone with ability to print money out of thin air funding him... cartels... see Transactions Withholding Attack.
legendary
Activity: 980
Merit: 1040
the pool op over at ghash.io is making mad money every single day.

With zero fees (allegedly, not sure if true), and paying out tx fees, just how is he making mad money on his pool?

Quote
it would take a massive, massive bribe to get him to want to let go of such an income flow.

Id say the opposite is true; setting up a zero fee pool is a relatively small investment to potentially gain control over the network. Im not saying I suspect ghash.io has nefarious intentions, but no one should risk bitcoin's integrity to the intentions of one single person. For bitcoins sake, point your miners to one of the smaller pools.
full member
Activity: 195
Merit: 100
No one will bother to gain 51%. The argument is simple. the 51% is the self-destruct button. They destroy the bitcoin system and they destroy themselves. Why sink the ship when they are onboard the ship?

Well, unless they are NSA.
legendary
Activity: 3766
Merit: 1217
Right now GHash is just 19% away (They already owns 32% of the total hashing power). Making me nervous.
legendary
Activity: 882
Merit: 1000
CPU-only mining that is botnet resistant and also limits the sizes of pools is very much needed.

So when can we expect that to appear?
Q1 2014

How could CPU mining be botnet resistent? What's different between a computer in botnet and a normal computer?
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