Heyo!
[cc @lehnberg]
I won’t be able to make the dev meeting, but I wanted to give a brief summary of betterhash: https://github.com/TheBlueMatt/bips/blob/betterhash/bip-XXXX.mediawiki
Betterhash is a proposal by Matt Corallo to modify the way that bitcoin mining pool participants obtain candidate blocks to mine. The proposal is for Bitcoin, but could be adapted for any PoW coin.
The most commonly used mining protocol for Bitcoin is known as Stratum. Under Stratum, mining pool participants receive full candidate block header from their mining pool to mine. This means that mining pools themselves control:
- Version bits, allowing them to signal readiness, or not, for protocol upgrades
– The transaction tree root hash, allowing them to select which transactions to include
Arguably, this decreases decentralization by putting these choices in the hands of the mining pool administrators, and not the mining pool participants.
Betterhash is a protocol to allow mining pool participants to make these choices, while still retaining the other benefits of pooled mining, namely decreased reward variability.
In short, betterhash allows pool participants to both select which transactions to include in a block as well as which protocol upgrades to signal readiness for.
This means that large mining pools will be less of a centralizing factor, and won’t be able to single-handedly block protocol upgrades, nor censor transactions from being mined.
I talked to Matt Corallo a few days ago, and had some concerns. Namely, could pool participants abuse tx selection or header construction by mining invalid blocks. However, this behavior essentially amounts to block-withholding, which is already possible with Stratum.
If grin were to adopt betterhash (or likely something like it) from the beginning, it might go a long way towards improving the ecosystem. Miners would have less of an incentive to accumulate hash rate, since it would not provide political power and leverage, as it does with bitcoin. Decreased ability to censor and block upgrades is of course an additional benefit.
Anyway, that’s all from me! Sorry I couldn’t attend the meeting.
Best,
Casey Rodarmor