Topic: Concern? over 50% of miners controlled by two pools - page 2. (Read 3553 times)

Epic confusion.

A 51% attack is then the attacker blockchain voluntarily ignore every other blocks. An honest 51% holder would accept the blocks found by other people.
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Well I'm sure as hell confused now if I weren't before. Are you talking about a blockchain fork, pseudo blockchains and such? No... wait, that can be done if the powerhouse pool wanted to do such a thing... but just to make sure I understand.... you're saying that if the pool with the majority of computing power is honest, it will accept other pools' blocks? Forgive my confusion... I just don't understand what this has to do with the price of rice in China.

So does anyone here are really know what 51% attack is? The worst thing it could do is to ignore some transactions by request even though it will be obvious to everyone and because of this it will immediately trigger the lowering price of bitcoin and the pool will collapse, all its participants will leave it as a free will. No one want to mine coins when its price lowering and the pools are almost identical.
51% attack do not allow you to steel money from someone else.
In case of any possible 51% attack market will not even feel this it will be like a sudden drop of price for a minute and it will raise back in hours.

Cash out before the panic crash or invest in whichever altcoin is likely to rocket upon news of a 51% attack on bitcoin. Millions to be made.

Even if the 2 pools hypothetically pulled off a 51% attack, who gains? If they do it, the market will instantly crash, the value for their saved coins is nothing.

P2pool is doing fine. It's on the chart linked above, but it's too small. The problem with p2pool is that the interface is not really user friendly and it can be finicky to get working especially with certain miners. If you really want to help the pool concentration problem, volunteer to help with p2pool. That doesn't have to be coding, it can be better guides and cheat sheets, pretty stats sites, etc.

Here's a thought experiment...How about have just one big pool and every miner is automatically a member of that pool.  That pool would of course get every block award.  The pool operator sends out the appropriate fractions of block award based on the hashing contribution of each miner.  As long as the pool operator didn't abuse their power this would be the most fair system.  Of course that degree of centralization would be ripe for abuse and corruption, if history is any guide.  Even if the operator *wanted* to be fair others could find ways to coerce the operator to allocate shares unfairly and cook the books to hide it by manipulating the statistics showing how many miners there are and their relative hash power.  It seems clear to me that having 1 pool with %100 of the hash power is bad.  That raises the question: Is 2 pools split 80%/20% any better?  How about 3 pools 60/35/5%?  Actually, when bitcoin really hits the big time (e.g. $5000 per coin?) then I believe any sufficiently large pool operator becomes a target of the sorts of people who are good at forced manipulation (e.g. governments, criminal organizations).


I think as long as people are in charge of operating mining pools there are opportunities for extortion, abuse, and corruption.

No.

Epic confusion.

A 51% attack is then the attacker blockchain voluntarily ignore every other blocks. An honest 51% holder would accept the blocks found by other people.

Look at you OP... got me challenging veteran members and I don't know what the hell I'm talking about 

Arguably it is still a marketplace problem in that there may be lack of confidence that the pool is honest, will stay honest, and won't be compromised by (internal or external) dishonest actors.

The pool model is highly problematic and isn't solved by starting a new low-fee pool as someone else suggested because a new (presumably smaller) pool will have payout variance that is too high. There are some very nice smaller pools right now that don't even reliably solve one block per week. The incentive for the individual miner is always to sign up with the bigger pools to get consistent payouts, and that's bad for the system as a whole.

The way out of this trap is with p2pool (or build a new system like it if you don't like p2pool).

Can you explain how it works, or how the pool can prevent from abusing that power? Can that power be abused - oh, hell yes! I'm not talking about the many things that a pool powerhouse has the ability to do.... But how can said pool prevent from NOT taking other miners' block rewards and transaction fees? This isn't intentional - As the authority on the network (so to speak), clients will believe the pool's hashed transaction block over any other. That means the pool will win all transaction conflicts, and get the rewards.

I'll accept what you said that there's no problem with having more than 50% of the hashing power, but you've got to explain just a lil... after all, I'm still an infant in this world too.

No, that's not how it works. There is no problem with a pool having more than 50% of the hash power as long as they don't abuse that power.

You did good, hehe.

A 51% Attack doesn't have to be intentional, does it? If any pool had 60% of the hashing power, an attack would be forthcoming. The pool doesn't have to try to do it, it will, which is why the pools cap themselves. Blocks other miners solve would be orphaned left and right... The longest chain always win the conflict, right? That isn't to say it was done intentionally or with malice. But whoever has the upper hand would benefit from the block rewards and transactions fees of those resolved 'conflicts.'  On the other hand, if a pool wanted to orchestrate an attack... well, I guess that's another topic.

Support p2pool

They would be able to do everything.

Maybe modify just some transactions... because someone pay them for that... you know, corruption... something wich will pass unnoticed but important...who know... no proof that "they" did it...

Please don't talk down to people like that, it's not constructive, and given the nature of a lot of the conversations on this board, I don't think this was an invalid question.

Answers:

Yes. Yes.  : https://en.bitcoin.it/wiki/Weaknesses#Attacker_has_a_lot_of_computing_power

No.  I'm not sure what would happen.  If you have a good idea, and think that the consequences make it not something to worry about, I think many people would like to know that information.  That's pretty much why I asked.  Should we be concerned?  It sounds like no, but you haven't really explained why.

Here are my conjectures:

It seems like the double spend is probably not practically useful, since it's less of a double spend and more of a "spend and then unspend", which only helps if you're getting something from someone else for spending the bitcoin.  And in that case, the other party would start squawking up a storm about it, so it  wouldn't go unnoticed.

Forcing transactions not to be confirmed seems like it might be something to be concerned about.  It could be hard to determine why its happening, and could be used as a weapon against people that piss off the pool.  Of course, that requires the pool to know which transactions belong to that person, which is sorta the whole point of anonymity in the blockchain.... but I'm not sure how hard it would be in practice.

Preventing other miners from getting blocks seems like the most likely attack vector, since it could be the hardest to recognize.  The top two pools could just give themselves 10% more block awards by rejecting 10% of blocks submitted from outside their pools, and waiting until one of them finds the block.  I'm not sure how obvious that would be to people watching transactions on the block chain.  The benefits are obvious - they get 10% more block awards than they're entitled to.

I'm relatively new to bitcoin, so some or all of this may be off, feel free to tell me where I've gone wrong, after all, I am trying to learn.

the whole point of bitcoin is being a decentralized currency... yeah, I don't think any mining pool will want to have control over the blockchain, that would probably destroy bitcoin and obviously miners don't want that.. but I'm still concerned 

what happen with p2pool?

This ^^^^

My biggest fear is that the Star Trek Enterprise will come back through time to our century and pull off a 51% attack.

I think they are only ones with their super advanced technology that could pull it off.

Hell, Commander Data could probably do it with his positronic brain. 



 

Well if you are that concerned start your own pool that offers paying transaction fees, mines Altcoins and has low pool fees.

No one will mine in a pool that pays less....

Do you even know what a 51% attack is?  Do you know what can be done using it?  Do you know what would happen if a pool tried to do it?

Let's do a mind experiment.  Assume BTC guild, right now, has 60% of all the hashing power.  Now explain to me exactly what they would do in order to pull off a "51% attack", exactly what they would accomplish by doing it and most importantly exactly why they would do it.