Re: [bitcoin-dev] [BIP Proposal] BetterHash Mining Protocol Replacements

From: Chris Pacia <ctpacia@gmail•com>
To: bitcoin-dev@lists•linuxfoundation.org
Subject: Re: [bitcoin-dev] [BIP Proposal] BetterHash Mining Protocol Replacements
Date: Tue, 5 Jun 2018 21:26:35 -0400	[thread overview]
Message-ID: <039bd3d3-c71c-8d40-7456-bc78fc0c7123@gmail.com> (raw)
In-Reply-To: <92215b88-75a4-6be7-dec6-89c567a74a9a@mattcorallo.com>

Really like that you're moving forward with this. A few months ago I was 
working on something similar as it seemed like nobody else was interested.

In regards to the specific proposal, would it make sense to offer a tx 
subscription endpoint in addition to TRANSACTION_DATA_REQUEST? Such an 
endpoint could respond to the subscription with the current full list of 
transactions and then push the diff every time a new template is pushed. 
A client that wants to inspect and modify the transactions would use 
quite a bit less data than polling the request endpoint.

On 06/05/2018 02:44 PM, Matt Corallo via bitcoin-dev wrote:
> Been working on this one for a while, so its already been through a few
> rounds of feeback (thanks to all those who already have provided feedback)!
>
> At a high level, this meets a few goals:
>
> 1) Replace getblocktemplate with something that is both more performant
> (no JSON encoding, no full transactions sent over the wire to update a
> job, hence we can keep the same CTransactionRef in Bitcoin Core making
> lots of validation things way faster), more robust for consensus changes
> (no need to add protocol changes to add commitments ala SegWit in the
> future), and moves more block-switching logic inside of the work
> provider (allowing Bitcoin Core to better optimize work switching as it
> knows more than an outside pool server, specifically we can play more
> games with how we do mempool eviction, empty block mining, and not
> mining fresh transactions more easily by moving to a more "push" model
> from the normal "pull" getblocktemplate implementation).
>
> 2) Replace Stratum with something more secure (sign messages when
> applicable, without adding too much overhead to the pool), simpler to
> implement (not JSON-wrapped-hex, no 32-byte-swapped-per-4-byte-byteorder
> insanity), and better-defined (a clearly written spec, encompassing the
> various things shoved backwards into stratum like suggested difficulty
> in the password field and device identification by setting user to
> "user.device") with VENDOR_MESSAGEs provided for extensibility instead
> of conflicting specifications from various different vendors.
>
> 3) Provide the ability for a pool to accept work which the users of the
> pool selected the transactions for, providing strong decentralization
> pressure by removing the network-level centralization attacks pools can
> do (or be compromised and used to perform) while still allowing them
> full control of payout management and variance reduction.
>
> While (1) and (2) stand on their own, making it all one set of protocols
> to provide (3) provides at least the opportunity for drastically better
> decentralization in Bitcoin mining in the future.
>
> The latest version of the full BIP draft can be found at
> https://github.com/TheBlueMatt/bips/blob/betterhash/bip-XXXX.mediawiki
> and implementations of the work-generation part at
> https://github.com/TheBlueMatt/bitcoin/commits/2018-02-miningserver and
> pool/proxy parts at https://github.com/TheBlueMatt/mining-proxy (though
> note that both implementations are currently on a slightly out-of-date
> version of the protocol, I hope to get them brought up to date in the
> coming day or two and make them much more full-featured. The whole stack
> has managed to mine numerous testnet blocks on several different types
> of hardware).
>
> Matt
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists•linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>