Subject: Re: [bitcoin-dev] [Bitcoin Advent Calendar] Decentralized Coordination Free Mining Pools

From: Bob McElrath <[email-masked]>
Date: Wed, 15 Dec 2021 00:12:00 +0000

You are hand waving. Attempting to redefine terms to justify your argument is
intellectually dishonest. Bitcoin pools have *always* been about variance
reduction. Your window function fundamentally CANNOT be used to hedge hashrate.
Various suggestions below introduce dangerous new games that might be played by
miners.

The fact is that the half-baked design you posted is less than useless, and
doesn't do anything that anyone wants.

You are trying to justify CTV by making it be all things to all people. "When
all you have is a hammer, every problem looks like a nail".  Instead I humbly
suggest that you pick ONE problem for which CTV is demonstrably the right and
best solution, instead of snowing us with a ton of half-baked things that
*could* be done, and often don't even require CTV, and some (like this one)
fundamentally don't work. I do like some of your ideas, but if you had to pick
just one "use case", which would it be?

Jeremy [[email-masked]] wrote:
> Bitcoin didn't invent the concept of pooling: https://en.wikipedia.org/wiki/
> Pooling_(resource_management). This is a Bitcoin Mining Pool, although it may
> not be your favorite kind, which is fixated on specific properties of computing
> contributions before finding a block. Pooling is just a general technique for
> aggregating resources to accomplish something. If you have another name like
> pooling that is in common use for this type of activity I would be more than
> happy to adopt it.
> 
> This sort of pool can hedge not only against fee rates but also against
> increases in hashrate since your historical rate 'carries' into the future as a
> function of the window. Further, windows and reward functions can be defined in
> a myriad of ways that could, e.g., pay less to blocks found in more rapid
> succession, contributing to the smoothing functionality.
> 
> With respect to sub-block pooling, as described in the article, this sort of
> design also helps with micro-pools being able to split resources
> non-custodially in every block as a part of the higher order DCFMP. The point
> is not, as noted, to enable solo mining an S9, but to decrease the size of the
> minimum viable pool. It's also possible to add, without much validation or
> data, some 'uncle block' type mechanism in an incentive compatible way (e.g.,
> add 10 pow-heavy headers on the last block for cost 48 bytes header + 32 bytes
> payout key) such that there's an incentive to include the heaviest ones you've
> seen, not just your own, that are worth further study and consideration
> (particularly because it's non-consensus, only for opt-in participation in the
> pool).
> 
> With respect to space usage, it seems you wholly reject the viability of a
> payment pool mechanism to cut-through chain space. Is this a critique that
> holds for all Payment Pools, or just in the context of mining? Is there a
> particular reason why you think it infeasible that "strongly online"
> counterparties would be able to coordinate more efficiently? Is it preferable
> for miners, the nexus of decentralization for Bitcoin, to prefer to use
> custodial services for pooling (which may require KYC/AM) over bearing a cost
> of some extra potential chainload?
> 
> Lastly, with respect to complexity, the proposal is actually incredibly simple
> when you take it in a broader context. Non Interactive Channels and Payment
> Pools are useful by themselves, so are the operations to merge them and swap
> balance across them. Therefore most of the complexity in this proposal is
> relying on tools we'll likely see in everyday use in any case, DCFMP or no.
> 
> Jeremy
> !DSPAM:61b8f2f5321461582627336!
--
Cheers, Bob McElrath

"For every complex problem, there is a solution that is simple, neat, and wrong."
    -- H. L. Mencken