Topic: Possible covert mining attack (in progress???) - page 3. (Read 549 times)

Stealth? You wouldn't be doing stealth attacks with all that drama.
And a coordinated attack would certainly not look like this, with regions takins actions one after the other, with Bitmain still delivering gear outside of China right now pushing up the hashrate of the 'competition", allowing miners to pack gear and move it and allowing a ton of gear to be sold as we speak and shipped around the globe. You should take a look at channels where mining gear is sold in bulk and you would be amazed how much has been moved lately.

Plus, to mine on a separate chain, you would need yours to exceed the other and the one way to do that would have been to completely cut mining to the international chain at once, not by  - 15.97 %, - 5.30 %,- 27.94 % by those number if a secret chain is right now being mined is still below the main one and time will be shortly running out even in this fantasy scenario.

Now, why would the whole Chinese mining cartel do this and ruin themselves?
Let's assume they're doing this under orders from the Chinese government, then why wound't they have done this simply in secret, seizing all mining farms, arresting the owners or put them under surveillance, order them to stay put and mine on a secret chain and that's it, nothing would have been found in the western world till it would have been too late. What is happening right now is anything but stealth.

Correct, we should never do that. There is a very specific reason why it was removed from the code, and any changes would probably take a while for the network to adopt. Unless you know that someone is already doing so, then once you release the client, they release their own chain.

Now to address why it isn't necessary. There is no reason why anyone would do a 51% attack over a few hundred blocks. If you're in for the profits, your total gain must be at least the sum of the block rewards. So if we were to approximate it, over a hundred blocks, it would be currently 19 million dollars. Why would anyone spend 19 million dollars on an attack like this? If you want to make a statement, just orphan blocks as you go. People will panic, price will crash and it is so much cheaper than mining on a separate chain. Checkpoints are not fundamentally useful in nearly any motives for a 51% attack.

If we had a good pre-emptive measure against 51% attacks, it would have been implemented a long time ago.

They will know, we won't. If you're occupying a huge space and you consume a huge amount of electricity, either you're growing marijuana or Bitcoin mining. To confirm which is it, just go and take a look.

Well, perhaps they see it as a threat and they don't want to endorse any part of it. If you were to destroy Bitcoin, another crypto would just rise. This time even higher than Bitcoin, there is no point.

But theoretically if you wish to attack the main chain this way you can schedule your brand new S19s (maybe even new locations?) to be fired up at the right time. So the close to 50% is awfully close for my taste today . I only worry about the long term roll back possibility. As far as I see that's the only real -albeit theoretical- danger.

Crossing my fingers


Yeah, hence the quotation mark. Still happened continuously and fast. Of course it matches the story (China miners shutdown), so let's hope occam's razor is right. Crossing my fingers

I don't want to spread FUD. I too believe that this is small possibility only. I also believe what I explained is a possibility which we should be prepared considering the results of such an attack.

No it didn't drop 50+% and the drop wasn't any where near overnight.

If you go back as far as 13-May (48 days ago) the (ATH) diff was 25.0T which is 179EH
Now the diff is 14.4T which is 103EH
So that's -42.7% over 48 days, so certainly not greater than 50% like your over stated post is.

Even if this diff change is another -10% to 92.5EH, you still only get a total hash rate drop of -48.4% over the 63 days by then.

Yeah it is now getting closer to -50%, but certainly vary far from overnight 50+%

If instead we claim 'overnight' is 3 weeks, for last 2 diff drops we get a diff drop of ... -31.8% ...

The difficulty at the end of any 2 weeks (2016 blocks) is the average of that 2 weeks (2016 blocks), there's no magic hash rate drop that doesn't affect the diff change.

The current time is unique though. 50+% hash rate just disappeared "overnight" which makes it somewhat likely that a state actor (China) is using this proven hashrate to covertly attack Bitcoin. If  they can't control damage it maybe damage it a lot. Could be the best time to be pre-emptive? I mean irreversibility is one of the main selling point for bitcoin besides the hard coded supply. If any of these fail... could be pretty bad.


Indeed, that's why I thought it's somewhat possible that they didn't actually shut down.


Bitcoin matured a lot. China's problems are much bigger too. So I think this is probably the time CCP could have started to care
(especially as it won't cost them much, also they can show that they are the bid dog which they do care about)

That's true, but that doesn't mean it couldn't be used against a 51% attack...
In a real life example, bitcoin gold used checkpoints vs a 51% attack:

source: https://www.coindesk.com/attempted-51-attack-on-bitcoin-gold-was-thwarted-developers-say
source: https://www.coindesk.com/attempted-51-attack-on-bitcoin-gold-was-thwarted-developers-say

I'm not saying that this is what we should (ever) do, i'm just brainstorming potential idears and thinking about improbable scenario's (like the CCCP attacking bitcoin this way)

Checkpoints wasn't meant to prevent 51% attacks actually. You're either going to have someone babysit Bitcoin by assigning checkpoints or just having a moving checkpoints. Either of which isn't ideal and people seems to think that the checkpoints (often thousands of blocks deep) were meant to prevent 51% attacks. Not true and we've switched it out in favour of assumevalid.

I actually vaguely remember someone (I think Gavin) mentioning something about limiting re-org blocks but that wasn't really developed any further AFAIK. There simply isn't any reason why anyone would want to attack Bitcoin, the total cost of the attack and your ASICs probably cannot be covered by the profits from the attack. It is really not in their best interest to try to attack Bitcoin, too little incentives. Just move elsewhere with your millions of dollars in ASIC investment and continue generating profits.

You probably won't know which are the larger farms, some of them were quite stealth with their operations due to the nature of it.

Your concerns aren't unfounded, motivations goes far beyond monetary. But given the evidence that we've actually been seeing, I highly doubt that would be the case. CCP probably doesn't lose sleep over Bitcoin anyways, any attacks would've happened far earlier.

Yes, I also think this would cause a "which is the real chain" war . Probably some kind of ETH ETC split.

I think it would be great to prevent it (I mean act before this actually happens - if at all happens). I mean this is a rare enough event to introduce a checkpoint?

On the other hand as long as anyone can have such a huge proven hashrate hidden the checkpoint would only postpone the issue. I think the only true solution would be to limit chain reorg to a large enough number. I believe 12 should be enough. That would force any attacking actor to publish the alternate chain sooner or loose it.

Exchanges and other players could protect themselves by accepting after six, but only allow withdrawal after 12.

Or just play the game and increase the visible hashrate as soon as possible...

I would be much happier if we would see the hashrate (visible) go up soon.

AFAIK, there is no limit as to how many blocks that can be reorganized.

I think the odds of china doing a 51% attack are very small tough, they'd probably just destroy bitcoin by doing this, but at a very big (energy, hardware and labour) cost. The destruction wouldn't be technical, but it would be the destruction of most of the trust in crypto.

It would be interesting tough to see how the community would react. In the past, checkpoints were used, hardcoded into the default core implementation. If there would be a consensus about adding a checkpoint against the non-CCP chain, there would probably be a fork: CCP-BTC and free-ish-BTC.
There would be pro's and con's against such a checkpoint tough... I guess everybody in the west would agree that a state-sponsored 51% attack isn't good, but i guess there would also be a large portion of the community that would oppose any interference with how the protocol works (so they'd be against checkpoints, even for a good cause).

Hi,

I don't want to be alarmist and this is not a Bitcoin dies FUD post. Just a theory as there is no proof.

The fact I started with:
50+% of mining capacity disappeared from the Bitcoin blockchain which has never ever happened. Difficulty is adjusting as it should, so nothing to see there.

But:
What IF this is a stealth syndicated attack by Chinese miners?

Example/imagine:
They didn't really shut down. They just forked the Bitcoin blockchain and started selfish mining ever since on an alternate private chain (eg. withholding all the blocks they find and building their own private chain). They can do this for long time and release at once the new, longer chain. As it has more PoW (as long as they have the majority hashrate) it will become the only chain accepted by all nodes. As far as I know there is no roll-back limit, so theoretically they can do this a month later (or more).

All the coins mined on the public chain between the two dates gone. All the transactions may or may not be included. Those with knowledge of this attack could have cheated (like sending coins to exchanges, withdraw the fiat/altcoins and a month later getting back the coin because they sent it to a different address sooner on the alternate chain).

Personally I don't think that the CCP would play along. But that doesn't mean it's impossible.

Do you know any limitation in the protocol which would prevent this (eg. rollback limit?)?
Do we have any hard proof that those huge (at least the known really big ones) mining farms are actually off?

Cheers
Steve