Bitcoin's 10000 TH network is extremely vulnerable

[CoinCidental]

The more hashing power you are producing the more expensive it costs when you pass a certain level of stability.

I think if it could be done they would have done it, no point in waiting this long.

i agree
they could have killed it last year  for 10% of the every rising cost to kill it  now

anyway ,btc is  a fly on the windscreen of the fast car  that is the  global economy

[lnternet]

And what is the fear exactly?  That big banks will spend a few tens or hundreds of millions of dollars so they can doublespend on Satoshi Dice?

they make a chain which includes no tx. they will have the longest chain, so your block which has tx in it doesn't get into the chain.

Besides, maybe the mining pools could get together very quickly to balance out the network.

you don't seem to understand the meaning of 51%

[droptable]

And what is the fear exactly?  That big banks will spend a few tens or hundreds of millions of dollars so they can doublespend on Satoshi Dice?

they make a chain which includes no tx. they will have the longest chain, so your block which has tx in it doesn't get into the chain.

Besides, maybe the mining pools could get together very quickly to balance out the network.

you don't seem to understand the meaning of 51%

you can stop the blockchain from including meaningfull transactions.
you just stop putting in transactions in your new found blocks.

so it will take forever for a transaction to be transfared.
the intrinsic use of bitcoin would be destroyed.

//yes, if the poolowners and the comunity work togehter they could fight back, eg
// if your new-found-block deosnt cointains x transactions it is not valid, etc...

[Gabi]

And what is the fear exactly?  That big banks will spend a few tens or hundreds of millions of dollars so they can doublespend on Satoshi Dice?  Besides, maybe the mining pools could get together very quickly to balance out the network.

Please learn what a 51% attack is before posting.

[jaked]

If bankers had a fraction of the faith/expectations/awareness in BTC as people here do, they'd be very concerned by it.
Fortunately, they don't.

By the time BTC becomes a real threat to them, it'll be too late for them to stop it.


BTW, you can't buy 10,000TH without raising the ASIC/GPU prices significantly.
Even if you develop it silently, your suppliers will raise their prices.

Also, putting additional hash power into the network will raise the difficulty.
Putting up a 51% attack will require much more than $10m.

[CoinCidental]

And what is the fear exactly?  That big banks will spend a few tens or hundreds of millions of dollars so they can doublespend on Satoshi Dice?

they make a chain which includes no tx. they will have the longest chain, so your block which has tx in it doesn't get into the chain.

Besides, maybe the mining pools could get together very quickly to balance out the network.

you don't seem to understand the meaning of 51%

its not that simple
if i arrive today with my 51%  i cant  negate everyone else and the history
of btc

[newguy05]

many misconceptions, addressing 2 points...

market cap is just a measure. it bears no relation to any real life value. saying you can attack a 10 billion market cap with a 10 million investment compares two unrelated values; both are in USD but they are still not comparable. bitcoin has a market cap of 10b, but that does not mean that it is worth 10b.

It bears all the relations to real life value.  I give you a simpler example - lets say apple computers is worth 500 billion usd bookvalue.  But there is an otc contract that allow you to buy(destroy) the company for 5 billion, what do you think will happen? 

-----------------------

The notion that if bitcoin is gone it will be quickly replaced by another alternative cryptocurrency and everyone goes on their merry way is patently false. Virtual currency is nothing but the faith of the community supporting it. It is a very difficult task for another virtual currency to re-achieve the same level of trust, faith, and popularity of bitcoin if it is gone. Again creating the network/currency is easy, but having people using it is not.

Same as saying, if all the gold disappeared tomorrow, it's easy to just use copper as replacement, everyone will just accept it and treat copper as gold....

[newguy05]

its not that simple
if i arrive today with my 51%  i cant  negate everyone else and the history
of btc

no i think you can, the 51% is a one touch loss, once hit it's game over. History is fine, but everything at that moment cannot be trusted, when that happens the network/trust collapses on itself.

[CoinCidental]

the blockchain isnt going to re-write itself
any effort to fork it or whatever may be ok until its noticed (rapidly id imagine )
even then they dont stand to gain the entire network under my understanding

id be a lot more worried with sha -256 being cracked but the posibilites of that
seem to be quite far away ........

i could be wrong ......but i dont think so

im sure someone with better understanding than me will tel you why a sudden 51%
would not wipe btc from the face of the world or leave all the coins in "evil hands " etc

[Gabi]

Yes you are wrong. A 51% attack=bitcoin is useless.

[newguy05]

the blockchain isnt going to re-write itself
any effort to fork it or whatever may be ok until its noticed (rapidly id imagine )
even then they dont stand to gain the entire network under my understanding

id be a lot more worried with sha -256 being cracked but the posibilites of that
seem to be quite far away ........

i could be wrong ......but i dont think so

im sure someone with better understanding than me will tel you why a sudden 51%
would not wipe btc from the face of the world or leave all the coins in "evil hands " etc

no i am not saying the whole thing just drops dead the second you have 51% control, but at that point it is pretty much game over a slow death.  I am sure whoever does it will not just put exactly 51%, they would do something large like 3-5x the network. So for the good guys trying to counter and correct, they will need to bring online just as much hash power in short amount of time, which isnt going to happen.  Yeah if someone has the same 3-5x network power at standby, then as soon as detected it can be corrected.  But that's almost never going to happen.

But that's not really my point, 51%, 100%, 200%, 400% hardware, that's all chump changes. My point is the network is extremely vulnerable right now from companies or resourceful individuals who wants to kill it. They havent because bitcoin isnt big enough to affect their bottomline..yet.

[kendog77]

I was just looking at the bitcoin difficulty chart and realized how small this network really is despite the extreme difficulty increases over the last 2 years.  Lets get to it:

1) Currently difficulty is at ~10,000 TH
2) Single 1 TH mining box cost ~$1000 to manufacture (reality is much less than 1k, but for easy calculation lets use $1k)
3) To destroy the bitcoin network you need to control 51% of the network.
4) To bring 10,000 TH (assume evildoer wants to be thorough) online it will cost:  10,000 * $1000 = $10million,  add on another $10millon for R&D,  $20million total.
5) Goldman saches makes ~$30million a day in NET revenue (same with most other banks)
6) It will cost a SINGLE bank HALF day's net revenue to wipe bitcoin out - less than their office supply budget.

We are just an ant...not even ant, a microscopic organism in the financial world.  If bitcoin becomes too big or start hurting those bank's bottomline (transaction fees), all they need to do is sneeze and bitcoin is gone. And there is no regulation/anti-competitive laws to protect bitcoin, it is completely de-regulated at this point.

Heck it doesnt even have to be the banks, even a small hedge fund or single person with some cash can wipe out bitcoin in a single instance.

The other ironic thing is the market cap of bitcoin is around $12billion right now compared to the $20million to destroy it. It shows how far removed from reality everything is, i dont think people really thought this through. If bitcoin can be shorted, someone can just short it, then destroy the network for riskfree win.

The difficulty needs to increase by 1000X at the minimum ($10 billion) to provide some bare minimum security to bitcoin's network

Dont agree with what I said about the current state of bitcoin? then provide your reasons, i love to be proven wrong. But just cant find a fault in my numbers.

You're analysis is flawed and $20 million estimate is low for a number of reasons:

1.) In order for someone to pull this off, they would need $20 million worth of mining hardware today. If they start now, it will be months before they can bring the hardware online, at which time the difficulty will be much higher. In less than 5 days, the difficulty will go up another 25% so they will need $25 million worth of hardware.

2.) The analysis only covers the manufacturing and development costs, and ignores the cost of labor to set everything up, power, and facilities to run 10,000 TH. The ignored costs are not small.

3.) If someone really could bring 10,000 TH online today for $20,000,000, that setup would earn almost $3,000,000 in bitcoin per day. It doesn't make any sense for someone to spend $20,000,000 to destroy something that would earn them $3,000,000 per day.

4.) If Bitcoin is destroyed, I have little doubt that users will switch to a non SSA-256 coin like Litecoin. Some other crypto that doesn't contain the flaw would take over, so anyone trying to destroy crypto would end up playing whack-a-mole and waste millions of dollars.

5.) If the user was malicious, I suspect they would have millions of dollars worth of liability and end up getting sued into oblivion. Can you imagine how much negative publicity a company would get for even trying to destroy Bitcoin?

[bittymymitty]

Can't see a financial service company doing this, but definitely can see a Government sponsored org looking into this.  China, US, or even the intelligence branch of a tiny little foreign nation could sponsor this attack and overrun the system.  There's almost no way of resolving it, if equipment gets too expensive, tiny home-based miners would stop mining and only large coops would be in the game, that would also lead to 51% vulnerability.  Difficulty will rise, but cost/hash will fall at the same rate, which keeps the cost of 51% attack relatively constant.  China has been cracking down lately, that recent ban on mining tutorials and equipment is concerning..

[gbianchi]

here they give really higher 51% attack cost:
http://www.coinometrics.com/bitcoin/brix

[runam0k]

Surely people would see this coming a mile off. You don't just bring 51% of the network online overnight.

Consider the massive losses existing miners, ASIC manufactures and Bitcoin users would face. I suspect there would be a concerted effort worldwide to increase hash rate. I'd definitely plug in my USB Erupter.

Is identifying and attacking the miner an option (relevant nodes or IP addresses)?

[toknormal]

There's always Power PC.

That's what Power PC was invented for - exactly to address this 51% issue that hangs around the neck of proof of work coins. Since it's a proof of stake coin it's far less vulnerable - just make sure you've got at least as much Power PC as you have Bitcoin and you'll be ok if the rollover ever happens.

[BeepBeep2]

There's always Power PC.

That's what Power PC was invented for - exactly to address this 51% issue that hangs around the neck of proof of work coins. Since it's a proof of stake coin it's far less vulnerable - just make sure you've got at least as much Power PC as you have Bitcoin and you'll be ok if the rollover ever happens.

You surely mean peercoin, and not IBM Power PC micro-architecture-
http://en.wikipedia.org/wiki/Peercoin

[toknormal]

You surely mean peercoin, and not IBM Power PC micro-architecture

  Sorry, I can't resist calling it that. Lived with that abbreviation for so many years it's tattooed on my brain.

(I'm actually on a private crusade to rename the coin     )

[cryptozark]

And what is the fear exactly?  That big banks will spend a few tens or hundreds of millions of dollars so they can doublespend on Satoshi Dice?

they make a chain which includes no tx. they will have the longest chain, so your block which has tx in it doesn't get into the chain.

Besides, maybe the mining pools could get together very quickly to balance out the network.

you don't seem to understand the meaning of 51%

Sorry.  I was rushing out the door and didn't get to elaborate.

Miners of *any* cryptocurrency would have vested interest in keeping bitcoin alive as it is the posterchild of crypto currency and an attack on bitcoin would cause confidence in all cryptocurrencies to take a HUGE hit, so much in the same way that mining pools and ASIC providers currently limit themselves from taking over too much of the network, the hashing power currently being used to mine alts would flock to bitcoin to try to balance things out, and that combined hashing power could balance out the hashing power of some outside attacker such as a government or big banking.  I don't mean in 1 big pool that would itself be over 51%, but basically I'm just stating the hash power reserves exist in the alts.

Of course you can't force people to switch their hashing power, but it seems like it would be in their best interest to do so to maintain the integrity of crypto as a whole.  

[lnternet]

Miners of *any* cryptocurrency would have vested interest in keeping bitcoin alive as it is the posterchild of crypto currency and an attack on bitcoin would cause confidence in all cryptocurrencies to take a HUGE hit, so much in the same way that mining pools and ASIC providers currently limit themselves from taking over too much of the network, the hashing power currently being used to mine alts would flock to bitcoin to try to balance things out.

I couldn't have guessed you meant that

It's a fair point, but I don't think the total alt-hashrate is that significant? If there was an attack on BTC of this kind Im sure it wouldn't be 1) obvious and  2) gradual and 3) close in terms of hashrate.

1) If I'm trying to become the 50%+ hast rate owner, I do so by slowly, by adding nodes legitimately. I may buy a mining pool or two, or just gain access to them. Then just wait for the right moment to change the protocol I use.

2) Once I have enough hast rate, I'm not releasing a bit day by day, so people notice empty blocks or a growing orphaned chain that someone keeps building. I suddenly change from normal mining to destructive mining.

3) I won't attack with 51%. I will attack with 55% or 60%, so even if everyone quickly goes to max hash by mining on CPU and switches from alts, I still keep over 50%.