Quote from: kano on November 25, 2015, 09:42:41 PM

Quote from: jxz on November 25, 2015, 09:22:40 PM

Quote from: kano on November 25, 2015, 09:14:36 PM

Quote from: JaredKaragen on November 25, 2015, 08:34:01 PM

See, with NH; they are trying to solve a block with your transaction; so a different hash all together. Theres no way for a renter to withhold blocks like that... you can see the live submissions/hashrate coming through the solo pool. I don't see that being faked at all.... unless the hash renter feeds garbage data to the pool (I would assume the pool would invalidate bad work?)
...

Incorrect.

Withholding is done by the miner - they simply don't return the particular share that is a block, they just return (some or) all other shares.
Even if they do this, the person renting out their hardware gets paid and so does the renting service.
You can't know in advance which work contains a block, you only know when you find a particular share that is better than network difficulty.

It has nothing to do with where you get your hashes from except the obvious that: if it was your own miner and you were solo mining you'd be throwing away your own block

Theoretically - would it be possible for a pool to send a miner the most recently solved blocks template immediately before the block change notification? In this situation the miner should send back the solved block, then the pool could then discard it and continue sending valid work. This could be a proof to see if blocks truly are being withheld.

I realize in this scenario some hash time would be wasted on an old block.

No for multiple reasons:

1) block change times on a pool are the #1 priority - slowing that down (by delaying work changes) is how you lose blocks and get orphans

2) the work base for each miner is different, so you can't send a miner the work base of the other miner that found the block
If the work bases weren't different, then miners would be wasting time mining the same work and getting the same results

3) there's no guarantee that 2 miners will find the same block with the same work since their speed and mining code may increment the extranonce differently or to a different level (due to speed)

Thanks.