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Sabotaging Bitcoin

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Re: Sabotaging Bitcoin

#201

Post by copirate »

palata wrote: post #187
copirate wrote: post #177

Earlier quoted context omitted.

But by withholding you also increase the risk that your first block will never end up in the main chain (if the remaining 90% find a block while you're withholding). And you would sill have 10% chance of mining another block if you don't withhold. What advantage does withholding give you?

> What advantage does withholding give you? One last time. By withholding, you have a headstart on the next block. If you can mine for longer, you increase your chances.

Mining on the hidden chain is not necessarily a head start. It would be if it was certain that this hidden chain will become the main chain. But if it doesn't, then mining on it was a waste, not a head start. Of course you don't know in advance, but that's exactly my point. If you don't know whether you're on the right track, you can't say you have a head start. And in the described situation, it's not guaranteed at all that the hidden chain will become the main chain.

The hidden chain can easily be discarded if the miner of the hidden chain doesn't find a 2nd block and if the miners on the public chain find a block and propagate it before the hidden chain is published. In that case, the public chain and hidden chains will be 2 competing heads, and other miners will decide which one wins. They will generally take the first block they saw, so most likely not the (previously) hidden chain. In that situation, mining on the hidden chain was a waste, not a head start. We could even say that the miners on the public chain had a head start. That's why I say there's no such thing as a head start.

Re: Sabotaging Bitcoin

#202

Post by copirate »

palata wrote: post #188
copirate wrote: post #184

Earlier quoted context omitted.

But to get 10 blocks ahead you have to withhold blocks before knowing you'll be ahead. If you don't get ahead, you'll likely lose the reward of the blocks you withheld. So, you have to risk a lot of rewards, and for what potential gain? If you win you get to discard some blocks of others. You don't get more rewards, you just make others earn less (and you push the difficulty down a bit). I can see how you get a chanc…

> But to get 10 blocks ahead you have to withhold blocks before knowing you'll be ahead. You KNOW you are ahead, because you found a block and nobody else has published a block.

Yes, but when you find that block you don't know whether you will be 10 blocks ahead in the future. You have to make the decision to put the reward of this block at risk before you know you'll be able apply your strategy. That's what I meant here. It is very costly on average because of the potential loss of the withheld blocks.

Re: Sabotaging Bitcoin

#203

Post by copirate »

sjducb wrote: post #196
copirate wrote: post #129

Earlier quoted context omitted.

But what do they gain by doing that? What's the edge? Starting earlier doesn't give you any advantage.

There is an advantage because occasionally you find the second block while the first block is still secret, then you release the two blocks in quick succession. That’s the edge.

What advantage does it provide vs not withholding? If you don't keep your first block secret and find a 2nd block, you get the same rewards.

On the other hand, if someone finds a block while you're keeping yours secret, it's very likely you'll lose the reward of your block.

So, you get a chance to discard the block of another miner, but you have to put your own block at risk of being discarded. Maybe there's a gain here, but it's not clear.

Re: Sabotaging Bitcoin

#204

Post by copirate »

rkagerer wrote: post #199
copirate wrote: post #137

Earlier quoted context omitted.

No it's not a race, it's a lottery. It would be like saying you've an edge if you start earlier at the roulette.

...it's not a race, it's a lottery. Yes, but everyone else is still buying tickets for yesterday's jackpot, while you're busy accumulating them for tomorrow's.

But yesterday's jackpot is still running, here. If you find a block on the public chain while the other miner kept their block secret, your block becomes the main chain. If they publish their block after you, both blocks compete for the head, but it's usually the first published one that wins.

Re: Sabotaging Bitcoin

#205

Post by LikesPwsh »

mrb wrote: post #105
free_bip wrote: post #104

Earlier quoted context omitted.

How are you so confident that it will never weaken? Especially since there will come a time when the block reward is literally 0.

Tx fees make up a bigger and bigger fraction of miner rewards over time.

Making up a bigger fraction doesn't mean that transaction fees will increase over time.

For L1 fees to actually increase over time, we need increased L1 throughput. Without that, increased demand for transactions causes more batching of transactions (mostly between exchanges).

Given the failure of BCH for pseudo-religious reasons I don't have much hope.

Re: Sabotaging Bitcoin

#206

Post by palata »

copirate wrote: post #201
palata wrote: post #187

Earlier quoted context omitted.

> What advantage does withholding give you? One last time. By withholding, you have a headstart on the next block. If you can mine for longer, you increase your chances.

Mining on the hidden chain is not necessarily a head start. It would be if it was certain that this hidden chain will become the main chain. But if it doesn't, then mining on it was a waste, not a head start. Of course you don't know in advance, but that's exactly my point. If you don't know whether you're on the right track, you can't say you have a head start. And in the described situation, it's not guaranteed at…

I think that at this point, you would have to learn more about probabilities. You're stuck at "I don't understand how having 51% chances to win is better than having 49%, because you cannot know the result in advance and there is a 49% chance that you lose, in which case you have lost".

Re: Sabotaging Bitcoin

#207

Post by blamestross »

georgefrowny wrote: post #183
emil-lp wrote: post #110

Earlier quoted context omitted.

If you mine a block without revealing it, not only are you the only one that can mine the next block after that, but everyone is mining on the "wrong head". There's of course the risk that someone finds a different head in the meantime, but otherwise, you waste competitors' resources, while you get an advantage on the next block.

What makes it more likely that your first block ends up the next head and you're not wasting your own time on the second one if someone beats you to the first one while you're holding off?

For an arbitrary block, nothing.

It doesn't have to be arbitrary. You know when a block was "lucky" and you found it ahead of average by a given percentile. You leverage those blocks.

Re: Sabotaging Bitcoin

#208

Post by copirate »

palata wrote: post #206
copirate wrote: post #201

Earlier quoted context omitted.

Mining on the hidden chain is not necessarily a head start. It would be if it was certain that this hidden chain will become the main chain. But if it doesn't, then mining on it was a waste, not a head start. Of course you don't know in advance, but that's exactly my point. If you don't know whether you're on the right track, you can't say you have a head start. And in the described situation, it's not guaranteed at…

I think that at this point, you would have to learn more about probabilities. You're stuck at "I don't understand how having 51% chances to win is better than having 49%, because you cannot know the result in advance and there is a 49% chance that you lose, in which case you have lost".

No, I'm saying it's not clear at all who is in a better position. I'd even argue that the miner hiding his block is in a worse position.

But I'll stop discussing that with you. It's pointless and you're way too condescending.

Re: Sabotaging Bitcoin

#209

Post by basilikum »

palata wrote: post #198
basilikum wrote: post #190

Earlier quoted context omitted.

That's only mathematically true. The advantage is way too small to be relevant. Your advantage is having exhausted a fraction of the search space. But that fraction is tiny. You're trying to find a hash with a value below a certain threshold (simplified said, a hash starting with a certain amount of zeroes). You do this by trying random inputs to the hash function. Every input has the same probability of getting an o…

> The advantage is way too small to be relevant. That's the whole question: is it relevant or not? Even if it makes mining slightly more profitable, that's a win. No need to remind you that those who mine do it exclusively for profit.

It's not. Your advancement is that of exhausting a part of the search space of SHA256 inputs for a given output. We would be in deep trouble if you made any significant advancements there or even got close to it by multiple orders of magnitude off.

Re: Sabotaging Bitcoin

#210

Post by palata »

basilikum wrote: post #209
palata wrote: post #198

Earlier quoted context omitted.

> The advantage is way too small to be relevant. That's the whole question: is it relevant or not? Even if it makes mining slightly more profitable, that's a win. No need to remind you that those who mine do it exclusively for profit.

It's not. Your advancement is that of exhausting a part of the search space of SHA256 inputs for a given output. We would be in deep trouble if you made any significant advancements there or even got close to it by multiple orders of magnitude off.

> We would be in deep trouble if you made any significant advancements there

Not necessarily. The whole idea is that it maybe more profitable to withhold a block for some time. "More profitable" means that you make more money at the end. Not that you make billions in a second.

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