Bitcoin Forum

http://www.reddit.com/r/Bitcoin/comments/27l8id/ghashio_at_47_hashrate_for_the_last_24_hours/

http://www.reddit.com/r/Bitcoin/comments/27lotn/people_dont_realize_how_serious_a_50_attack_is/

http://www.reddit.com/r/Bitcoin/comments/27ls92/people_need_to_realize_50_isnt_a_magic_line_it/

https://blockchain.info/pools

Ghash.io (from cex site) reached 47% in the last day. Now it is down to 39%. I assume people moved to a different pool. We all heard of the 51% attack.

Could something like this be initiated if it happens on Ghash.io (or if a bunch of people randomly switched to a majority pool)?

Is a 51% attack possible, is it preventable? and what does it mean for bitcoin? (similar thing happened to litecoin a few weeks ago @a big pool)

 When people say there is no incentive for them to be at 51%, I think of the numerous times humans have contributed to the extinction of a species, even though their livelihoods depended on keeping the species alive and thriving. I'm hoping history doesn't repeat itself here.

What can be done about this?

This 51% risk is the biggest obstacle to me buying more BTC. If I thought there was even the remotest possibility it could happen, I think I'd sell the coins I now have too :( Would love to hear from someone who really knows about it. And surely, if the governments wanted to put an end to BTC, they could organise it.

These "guilds" are the biggest threat to bitcoin. The problem is you cannot really stop them.

Why does everyone use Ghash?

Probably because it's the easiest and/or most profitable to use.
Or because people just don't know better alternatives.

If you think that 51% is some magic line that, if crossed, will suddenly cause the collapse of Bitcoin, perhaps you need to educate yourself regarding how mining works.

Why would Ghash.io want to go past 51%? It's like comitting financial suicide.
Yes you can steal coins if you go past 51%, but BTC will go into instant panic sell and crash since the trust is gone.
If you only get 0.5% of all minted coins you're getting filthy rich already....  8)

That said if they cross 51% or even 99% who says that they will abuse the system? I must say it would make me uneasy....

I also think many miners would shift to a different miningpool just to save bitcoin...

because people, most of them, are stupid. buying cloud hashing contracts is the reason.

Troll trader/FUD Spreader #1: "Damn, btc price hasn't budged in a few days.  We need some new FUD panic. We need the price to fall to get cheaper coins!"
Troll trader/FUD Spreader #2: "Yeah, but what FUD?  China ban again?"
Troll trader/FUD Spreader #1: "Nah, we tried that again a few days ago, didn't work.  People just don't care anymore."
Troll trader/FUD Spreader #2: "Willy bot?"
Troll trader/FUD Spreader #1: "Nah.  Old news, plus Gox is way dead."
Troll trader/FUD Spreader #2: "Bitstamp insolvency?"
Troll trader/FUD Spreader #1: "Won't work, people know they are pretty solid now."
Troll trader/FUD Spreader #2: "....hmmm..."
Troll trader/FUD Spreader #2: "Wait, I've got it!"
Troll trader/FUD Spreader #1: "What?  What?"
Troll trader/FUD Spreader #2: "The 51% attack FUD!  People haven't heard about that stuff in a while! Let's resurrect it, I'm sure it'll cause some panic again. We'll post like crazy on Reddit and other sites, and whip this back into a frenzy!"
Troll trader/FUD Spreader #1: "Perfect." <evil grin>

What most people fail to realize is that 51% does not mean BTC will suddenly drop off the face of the internet, nor will ghash be able to freely take coins as if a big button appeared for them as they crossed it.

They've also stated several times that they do not want to cross that line, as even if they did break bitcoin and give themselves a huge amount, who will buy it? Inflation such as that caused by a successful 51% attack does not cause a steady price - it would crash the moment they crossed the line, meaning they would get nothing out of it and the bitcoin community would be crippled, not something ghash wants considering they make most of their money from people trading btc!

 I thought 51% attack is just a waste of time like somebody told me long time ago?  ???

A 51% attack cannot create more coins other than the normal block reward, thus it cannot cause an increase in the inflation rate. https://www.youtube.com/watch?v=bTPQKyAq-DM&feature=youtu.be&t=48m56s

Easiest? NO.

P2Pool is the easiest because you don't have to register any account. Why the hell people still use centralized mining if everyone could just switch to p2p mining.

I wouldn't be particularly worried about a 51% attack. Even if someone had control of 51% of the mining power, it would not be in their benefit to try to manipulate the block chain. As soon as anyone discovered that the attack had taken place the value of bitcoin would permanently drop to zero. Bitcoin would no longer be non-centralized and nobody would want to use it due to the major security flaw. I don't think anyone will ever control 51% of mining power though without like quantum computing or something.

So china could use it to attack bitcoin?

I guess anybody could, but I don't think anybody would be able to

Until 2-3 days ago, the total hashrate went up to 98-99 Peta Hash. Since then, it has calmed down to 86-87 PHs. Cex/ghash responded by ramping up to 41-42 PHs and is currently sitting at 39 PHs. It's a little bit disconcerting because they had been hashing at around 35% for a long time and to see them ramp up to 45% of the total will cause many miners to move to other pools like bitcguild and eligius.

Cex/Ghash had promised that they would never go to 51%; however, they have not kept other promises, such as allowing cloud miners to mine at other than ghash.io pool.

As others have said above, it boggles my mind why anyone would buy GHs at cex, it's overpriced and you are charged outrageous fees and you are giving your hard earned money to crooks, swindlers and inside manipulators at cex. There must be lots of feeble minded people around the world.

Leave it to Reddit to get all bent out of shape and paranoid over this. I'm not particularly worried about a 51% attack. But I also think.... why aren't miners switching pools yet? Didn't this same thing happen a few months ago?

+ MF'ing 1

I dont understand 1 simple thing. Why on earth Ghash.io/Cex.io will try for double spend ? Their wealth is standing on BTC... is not it ?

The real danger is pool operator corruption not a single pool getting >50% hashing power.

Take gigahash and some other leading mining pool. Combine their hashing power and Bitcoin is done. DEAD. All hail to peercoin, you should start buying peercoins already (http://imgur.com/a/dG66c) as this coin is much more resistant to 51% attacks.

Someone controls the pool, right? That someone has a family to be tortured in order to bring down Bitcoin. If money won't corrupt the pool operator, there are other things that can be done.

Those who know history, might even look back to Molotov–Ribbentrop Pact which may very well happen in the context of leading pool operators.

1. Develop a 51% attack proof altcoin.
2. Bring down Bitcoin with the analogue of the Molotov–Ribbentrop Pact amongst pool operators.
3. Everyone switches to 51% attack proof coin.
4. Profit

I diversified to peercoin long time ago and been stake-mining for a year now.

https://i.imgur.com/9A0hsvg.jpg

Why wouldn't they be able to? What if they seized the mining hardware then used it to attack? Or use their leet hackers to take over the mining pools?

*watch*

Ghash.io is currently at 39% according to https://blockchain.info/pools.

There's no problem in Ghash.io reaching the 51% of the total hashrate, they have no interest into breaking the bitcoin party.

That's kind of messed up, though. If we want to protect the integrity of the network, it's in the interest of us all not to have one entity controlling so much of the network.

They won't. It would be completely counterproductive for them, lowering user trust.