Quote from: pesci on Today at 02:24:53 PM

Let's say my ASIC makes 1 billion attempts at finding a PoW value starting with 62 zeroes, and this is represented by 100 shares, and all of these attempts fail to find the PoW hence I don't win the new Bitcoins. How does the pool differentiate between my ASIC-generated PoW values, which are randomly generated, and an entirely random PoW that was never checked by an ASIC? So far I don't see anyone offering a cogent explanation.

Okay. When you submit a share, you submit the job ID, nonce, timestamp and every data needed to reconstruct your hash. The pool reconstructs your hash and checks if it is a valid share > X difficulty as specified by your client or your pool. PoW is a hash and you don't need an ASIC to generate a hash... Your hash is always rebuilt and validated by the pool, you cannot just submit random values because the pool checks it.

Just to contextualize it; when your ASIC takes 1 billion attempts at finding a block, it'll probably hit one hash that fits the difficulty (ie. 1) as specified by the pool. That is a valid share, even if the current difficulty is 10,000, because your pool specifies a much lower difficulty than the current PoW to validate that you are infact attempting to find a block. By submitting several valid shares, you are proving to the pool that you are contributing to the effort. You will probably understand this better if you can look at how pools actually work, perhaps starting with how the stratum protocol does the communication between the pool and the miner.

Quote from: pesci on Today at 02:31:34 PM

If a share doesn't include a single PoW that solves the block however, but only attempts to solve the block, what is the precise mechanism for proving the PoW value is not just an unchecked random number? I have an idea, but I'd prefer to hear someone who is in the know explain it.

A share does include a PoW. If you were to mine in a pool, you'll realize that your client finds and submits shares of X difficulty. The precise mechanism is as follows:

1. Pools sends the data required to construct a block and the difficulty for which it expects before a share is submitted. A share doesn't necessarily have to meet the target, it is just something to determine if a miner is in fact contributing to the pool.
2. With the data given, the user hashes to find a hash that meets the difficulty as specified by the block.
3. Once they find the share, they send it to the pool, together with the information necessary to reconstruct it. If the pool cannot reconstruct it to form a hash that meets a specific target, then it is invalid. It is futile to send any shares that don't meet the specified difficulty because they won't be considered by the pool.

I think you have a fundamental misunderstanding of Bitcoin, rather than how pool works. PoW is not a random number, PoW in Bitcoin is defined with the hash that is difficult to find, ie. your leading zeros in simplified terms.