How to end Bitcoin with as little as 15% of hashpower efficiently

[waaat?]

All you need is 10% to 20% of hashpower.

What you do:
Shortly before an anticipated natural (or forced by selling) decline in hashrate you put your extra hash on BTC to make difficulty go up.
Now you sell off massively or use natural dynamics to your advantage. Once the miners drop out (10% to 15% of the network is enough) you withdraw your extra-hash from it.
Result: bitcoin is stuck at high difficulty as it retargets only every 2016 blocks. Blocks could take hours to solve. This will cause a further decline in value and people selling off as soon the news spread (selling can be reinforced at this point by the attacker) which in turn will lower hashrate until solving blocks takes so long the next difficulty adjustement can't be reached. Basically bitcoin remains stuck at high diff and with no network.

So if someone wanted to destroy bitcoin he just needed to find a way to collapse hashrate by 30% to 50% which can be easily done with a combined strategy of:
-providing parts of the hash yourself to cause higher difficulty and to be withdrawn later
-using anticipated natural decline
-selling coins in massive amounts

it's cheaper and more effective than any other attack. Every government or bank can do it.

Every time a decline in hashrate would be anticipated this attack becomes possible. (like right now - this exact attack could actually be on its way as we speak)


reference:
https://bitcointalk.org/index.php?topic=912190.0

[deine mudder]

sure. They don't want to adress it though.

Pumping up the price before and then dumping it would also help.

If you would additionally spam the network with microtransactions it would be defunct immediately.

The tech is much more fragile and totally not as secure as people like to think especially bitcoin with his old design. This wouldn't be possible with most altcoins as they have faster difficulty retarget. Bitcoin is much more vulnerable to these attacks than any of the newer, more advanced alts.

[mestar]

Once the miners drop out (10% to 15% of the network is enough) you withdraw your extra-hash from it.
Result: bitcoin is stuck at high difficulty as it retargets only every 2016 blocks. Blocks could take hours to solve.

10 to 15% increase of 10 minutes is not 'hours'.  It is in fact 11 minutes.

[waaat?]

Once the miners drop out (10% to 15% of the network is enough) you withdraw your extra-hash from it.
Result: bitcoin is stuck at high difficulty as it retargets only every 2016 blocks. Blocks could take hours to solve.

10 to 15% increase of 10 minutes is not 'hours'.  It is in fact 11 minutes.

10% to 15% is what you directly control. It's about controlling hashrate indirectly with priceaction aswell as using natural movements which can easily amount to much more.
The point is: it's actually possible to force a drop of hashrate of 40% or more by pumping it artificially before a natural drop would occure.

The attack consists of many components and needs good timing but would end bitcoin on the spot.

[insidertradingeverywhere]

needs quite some recouces but would be much more fatal than just a 51% attack
And it's cheaper than 51% for sure.
Shocking stuff.

[mestar]

Explain again your "hours to solve" part.

[slacknation]

Once the miners drop out (10% to 15% of the network is enough) you withdraw your extra-hash from it.
Result: bitcoin is stuck at high difficulty as it retargets only every 2016 blocks. Blocks could take hours to solve.

10 to 15% increase of 10 minutes is not 'hours'.  It is in fact 11 minutes.

10% to 15% is what you directly control. It's about controlling hashrate indirectly with priceaction aswell as using natural movements which can easily amount to much more.
The point is: it's actually possible to force a drop of hashrate of 40% or more by pumping it artificially before a natural drop would occure.

The attack consists of many components and needs good timing but would end bitcoin on the spot.

for the same difficulty but half the hashrate will just mean blocks take double the time to be confirmed. so indeed we will end up with a slow network but not to the extend that it is unable to recover. Anyway this will only happen if the price of bitcoin crashes but if this becomes true then there is no value in bitcoins thus no need to employ your method to crash the bitcoin network.

[waaat?]

Explain again your "hours to solve" part.

hashrate drops on high difficulty by a considerable amount. The remaining miners now need much more time to solve blocks. Read up on what difficulty and difficulty retarget is.

[waaat?]

for the same difficulty but half the hashrate will just mean blocks take double the time to be confirmed.

i think this is a false assumption as diff should be calculated with another algo

[slacknation]

for the same difficulty but half the hashrate will just mean blocks take double the time to be confirmed.

i think this is a false assumption as diff should be calculated with another algo

would you be able to explain this further?
outputs of good hash functions can be accepted to be a uniform distribution

[newuser01]

no this would not work and it would be wasting money for nothing.

[waaat?]

for the same difficulty but half the hashrate will just mean blocks take double the time to be confirmed.

i think this is a false assumption as diff should be calculated with another algo

would you be able to explain this further?
outputs of good hash functions can be accepted to be a uniform distribution

https://en.bitcoin.it/wiki/Difficulty

no this would not work and it would be wasting money for nothing.

can you explain why?

[turvarya]

That wouldn't end Bitcoin. It might make some trouble, but even that wouldn't that big.
Even if you could drop the hashrate 50%(which is complete bullshit, since if it drops miners with older hardware just go in again), that just means double confirmation time. So what? It adjust after 4 weeks instead of 2 weeks, big deal ...

[waaat?]

That wouldn't end Bitcoin. It might make some trouble, but even that wouldn't that big.
Even if you could drop the hashrate 50%(which is complete bullshit, since if it drops miners with older hardware just go in again), that just means double confirmation time. So what? It adjust after 4 weeks instead of 2 weeks, big deal ...

why would miners with old gear go in on high difficulty? The hashrate doesn't make a difference for them, the difficulty does.
Well, we assume a further decline as time passes eventually leading to everyone drop out.

Price fall, mining even more unprofitable for the reason of low price aswell as long blocksolving. It's a chainreaction that just needs to be properly started.

[turvarya]

That wouldn't end Bitcoin. It might make some trouble, but even that wouldn't that big.
Even if you could drop the hashrate 50%(which is complete bullshit, since if it drops miners with older hardware just go in again), that just means double confirmation time. So what? It adjust after 4 weeks instead of 2 weeks, big deal ...

why would miners with old gear go in on high difficulty? The hashrate doesn't make a difference for them, the difficulty does.
Well, we assume a further decline as time passes eventually leading to everyone drop out.

And there you are wrong. The overall hashrate tells them if they find the block or somebody else finds the block. The difficulty just tells them how long it will take them(or someone else) to find it.
Why would we assume a further decline? Everybody knows, that there will be a new adjustment in 4 weeks max.

[waaat?]

That wouldn't end Bitcoin. It might make some trouble, but even that wouldn't that big.
Even if you could drop the hashrate 50%(which is complete bullshit, since if it drops miners with older hardware just go in again), that just means double confirmation time. So what? It adjust after 4 weeks instead of 2 weeks, big deal ...

why would miners with old gear go in on high difficulty? The hashrate doesn't make a difference for them, the difficulty does.
Well, we assume a further decline as time passes eventually leading to everyone drop out.

And there you are wrong. The overall hashrate tells them if they find the block or somebody else finds the block. The difficulty just tells them how long it will take them(or someone else) to find it.
Why would we assume a further decline? Everybody knows, that there will be a new adjustment in 4 weeks max.

the situation would be: high difficulty stuck and low hashrate
clones of bitcoin died this way before so it's actually not new.
What makes it possible is the long times between difficult adjustements.

[turvarya]

That wouldn't end Bitcoin. It might make some trouble, but even that wouldn't that big.
Even if you could drop the hashrate 50%(which is complete bullshit, since if it drops miners with older hardware just go in again), that just means double confirmation time. So what? It adjust after 4 weeks instead of 2 weeks, big deal ...

why would miners with old gear go in on high difficulty? The hashrate doesn't make a difference for them, the difficulty does.
Well, we assume a further decline as time passes eventually leading to everyone drop out.

And there you are wrong. The overall hashrate tells them if they find the block or somebody else finds the block. The difficulty just tells them how long it will take them(or someone else) to find it.
Why would we assume a further decline? Everybody knows, that there will be a new adjustment in 4 weeks max.

the situation would be: high difficulty stuck and low hashrate
clones of bitcoin died this way before.  

The Bitcoin network is much stronger than that of his clones. You can't really compare them.
There are even people in the network, who still mine for the fun of it or just to support Bitcoin, not to make a profit.

[waaat?]

That wouldn't end Bitcoin. It might make some trouble, but even that wouldn't that big.
Even if you could drop the hashrate 50%(which is complete bullshit, since if it drops miners with older hardware just go in again), that just means double confirmation time. So what? It adjust after 4 weeks instead of 2 weeks, big deal ...

why would miners with old gear go in on high difficulty? The hashrate doesn't make a difference for them, the difficulty does.
Well, we assume a further decline as time passes eventually leading to everyone drop out.

And there you are wrong. The overall hashrate tells them if they find the block or somebody else finds the block. The difficulty just tells them how long it will take them(or someone else) to find it.
Why would we assume a further decline? Everybody knows, that there will be a new adjustment in 4 weeks max.

the situation would be: high difficulty stuck and low hashrate
clones of bitcoin died this way before.  

The Bitcoin network is much stronger than that of his clones. You can't really compare them.
There are even people in the network, who still mine for the fun of it or just to support Bitcoin, not to make a profit.

sure. The way presented here makes it affordable though.
The few hobbyminers left will not want to mine if they can't even find a block in a day.
Clones is just smaller scale and happend on accident (or not) with large hash being on and off.

[turvarya]

That wouldn't end Bitcoin. It might make some trouble, but even that wouldn't that big.
Even if you could drop the hashrate 50%(which is complete bullshit, since if it drops miners with older hardware just go in again), that just means double confirmation time. So what? It adjust after 4 weeks instead of 2 weeks, big deal ...

why would miners with old gear go in on high difficulty? The hashrate doesn't make a difference for them, the difficulty does.
Well, we assume a further decline as time passes eventually leading to everyone drop out.

And there you are wrong. The overall hashrate tells them if they find the block or somebody else finds the block. The difficulty just tells them how long it will take them(or someone else) to find it.
Why would we assume a further decline? Everybody knows, that there will be a new adjustment in 4 weeks max.

the situation would be: high difficulty stuck and low hashrate
clones of bitcoin died this way before.  

The Bitcoin network is much stronger than that of his clones. You can't really compare them.
There are even people in the network, who still mine for the fun of it or just to support Bitcoin, not to make a profit.

sure. The way presented here makes it affordable though.
The few hobbyminers left will not want to mine if  they can't even find a block in a day.

Do you really think, professional miners would trash their expensive hardware, they can't use for anything else than mining, when the difficulty goes up? That would be pretty stupid from an economical POV.

[Flashman]

Title needs to be changed to, "How to slightly inconvenience bitcoin by throwing 70 million dollars away"