if miners worked together

[Anddos]

ok so if every miner switched off there miners at the same time,the difficulty would go back down right to a very low level,so once the difficulity has gone all the way back down and then miners startup again which in turn drives the difficulty back up after 12 days or so again why wouldnt miners then switch off there miners again and wait 12 days or so for the difficulty to go back down again, so everytime you do this you get 12 days of mining at full capcity at a low difficulty because the difficulty is not instant and changes overtime. you could do this over and over if all miners colabrated together and you would make alot more coins.

[cloverme]

If a block is found under 10 minutes it would adjust the difficulty again upwards and so on. It's an interesting question, it would probably cause all sorts of problems for awhile on the bitcoin client network for awhile. In reality, no one would stop mining to see what would happen.

[gigq]

This happens all the time on the alt chains, which is one of the good thing about having alternative crypto currencies.

Basically a coin might be very profitable to mine so miners flock to it and drive the difficulty up.  Then when it adjusts the difficulty spikes and it is no longer profitable so everyone changes to another coin.  So you are correct that the difficulty will drop back down but there is a major issue.

The difficulty change is defined as every 2016 blocks not a set amount of time.  So when the difficulty is low and everyone flocks to it the 2016 blocks get mined very quickly.  Then difficulty rises and everyone leaves and it takes proportionally more time.  So if only 10% of miners are left it will take 10x more time to mine the next 2016 blocks.  Once those blocks are mined the difficulty readjusts and it gets easier again.  So you see everyone doesn't really get more blocks in the end because the easy blocks go quickly and the hard blocks take forever.

The other issue is that blocks are slow to get on the chain so sending coins takes forever to get confirmations and it slows down using the coin.  I remember terracoin had a big problem with this back in the day and it was a vicious cycle as miners kept coming and going in swarms.

[Calhil]

ok so if every miner switched off there miners at the same time,the difficulty would go back down right to a very low level,so once the difficulity has gone all the way back down and then miners startup again which in turn drives the difficulty back up after 12 days or so again why wouldnt miners then switch off there miners again and wait 12 days or so for the difficulty to go back down again, so everytime you do this you get 12 days of mining at full capcity at a low difficulty because the difficulty is not instant and changes overtime. you could do this over and over if all miners colabrated together and you would make alot more coins.

The difficulty doesnt change with time, it changes with block height. You would get on average the same amount of coins either way.

[JPSelzer]

It is an utopian situation. In real life miners will never organized together and stop all in one moment

[Coins4life]

Doubt this would work or ever happen Tbh

[film2240]

The only way I see this as a viable option is if miners use multi coin pools that auto switch to the most profitable coin based on an algorithm which is what I found was responsible for significant drops and rises in difficulty with some alt coins.

[Ismeld]

If grandma had balls, she'd be grandpa

[cccminer]

Classic game theory problem.

If everyone did this,  the "cheaters" would be rewarded by jumping in and mining during the "downtime".   Once everyone recognizes this, then everyone becomes a "cheater" which puts us back to square 1.

Which is a short way of saying it'll never happen.

[9inety7even]

Classic game theory problem.

If everyone did this,  the "cheaters" would be rewarded by jumping in and mining during the "downtime".   Once everyone recognizes this, then everyone becomes a "cheater" which puts us back to square 1.

Which is a short way of saying it'll never happen.

Exactly. Add to that the fact that the "cheaters" would also likely be able to double spend if they banded together.

[jayson001]

Practically, this will never happen in btc mining. some alt coin maybe.

[irrational]

The only way I see this as a viable option is if miners use multi coin pools that auto switch to the most profitable coin based on an algorithm which is what I found was responsible for significant drops and rises in difficulty with some alt coins.

Coin hopping... I like it!

[kthejung]

The miners are in competition with each other to find the block.  The difficulty going up weeds out obsolete miners and the uncommitted; which is good for competitors.

[Bit_Happy]

This happens all the time on the alt chains, which is one of the good thing about having alternative crypto currencies.

Basically a coin might be very profitable to mine so miners flock to it and drive the difficulty up.  Then when it adjusts the difficulty spikes and it is no longer profitable so everyone changes to another coin.  So you are correct that the difficulty will drop back down but there is a major issue.

The difficulty change is defined as every 2016 blocks not a set amount of time.  So when the difficulty is low and everyone flocks to it the 2016 blocks get mined very quickly.  Then difficulty rises and everyone leaves and it takes proportionally more time.  So if only 10% of miners are left it will take 10x more time to mine the next 2016 blocks.  Once those blocks are mined the difficulty readjusts and it gets easier again.  So you see everyone doesn't really get more blocks in the end because the easy blocks go quickly and the hard blocks take forever.

The other issue is that blocks are slow to get on the chain so sending coins takes forever to get confirmations and it slows down using the coin.  I remember terracoin had a big problem with this back in the day and it was a vicious cycle as miners kept coming and going in swarms.

Me too, I remember when terracoin was getting "tested".

[googlemaster1]

I could see the appeal for HUGE pools to try this for 10 days, but then again, lets say you cut the difficulty by 90%, and then then all the miners went online after the readjustment, how many orphans would occur if you were finding a block every minute?  Who knows, maybe someday it will be so institutionalized they'll have a perfect strategy for this, but that would require all the big players to collude, and that just seems unlikely.

[freebit13]

The 13th difficulty change was negative wasn't it? Never say never...

[blubberli]

This won't happen (see "game theory" above).

But what if one of the big pools would be shutdown by a hacker for a couple of days?

[JoelKatz]

ok so if every miner switched off there miners at the same time,the difficulty would go back down right to a very low level,so once the difficulity has gone all the way back down and then miners startup again which in turn drives the difficulty back up after 12 days or so again why wouldnt miners then switch off there miners again and wait 12 days or so for the difficulty to go back down again, so everytime you do this you get 12 days of mining at full capcity at a low difficulty because the difficulty is not instant and changes overtime. you could do this over and over if all miners colabrated together and you would make alot more coins.

That's just not how the difficulty adjustment works. First, if people stop mining, the difficulty won't go down. People have to mine blocks for the difficulty to adjust. Second, if people resume mining at a low difficulty, the blockchain will progress more rapidly and the difficulty will just adjust sooner. Also, miners benefit from keeping the price of Bitcoin high, so they'd be slitting their own throats.

[JoelKatz]

This won't happen (see "game theory" above).

But what if one of the big pools would be shutdown by a hacker for a couple of days?

This happens so often (either through denial of service attacks or just outages) that serious miners already configure their equipment to switch pools automatically.

[blubberli]

This happens so often (either through denial of service attacks or just outages) that serious miners already configure their equipment to switch pools automatically.

Aye, but I thought of pools who have their own hardware (e.g. CEX.IO/HASH.IO).