The luck has been not good lately.
I wonder if wizkid somehow performs checks against block withholding.
Sorry if it's been asked already.
Why would you do that? I would understand if it would be PPS so you would keep difficulty down... As far as I know you can't submit found block yourself... Not sure exactly why but that is what I was told...
A miner that finds a block (in a pool) cannot claim it for itself, because by doing so, he would invalidate the hash, and could not claim the block. An if he was mining mining solo, but submitted his shares to the pool, the pool would reject it because the do not match what it expects.
So a miner willing to benefit from the profit splitting of a pool has to mine "for" the pool and cannot "steal" the pool the blocks it finds. HOWEVER, it can choose not to submit winning shares, but submit all other shares. So he benefits from the other pool miner's work, while not helping the pool at all.
Such behavior is usually pointless for a miner: It -HAS- to find shares and submit them to the pool to get his share of the pool's reward, so sorting a "winning" share out of it cannot help him spend less electricity/bandwith/work for the same reward. In fact, by witholding the winning shares, he hurts everybody in the pool equally, including himself.
Actually, withholding blocks (temporarily) can be very profitable if you have a lot of hashing power, especially if you can submit the blocks yourself. I'm not sure to what extent the owners of Eligius want me to describe the process, though. Probably not much given Luke's previous comments about sharing information.
As Luke said, it's a cat-and-mouse game. But the mouse is anonymous and can make copies of itself pretty much infinitely.
However, if attackers started to doing this on every pool, then it would cancel out, because the difficulty would decrease by the exact same amount the attacker controls. So it is an attack against individual pools, not against bitcoin itself.
It could be part of a larger attack, though. Pools let you attack the network while still collecting more than 99% of your rewards.
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