That’s interesting. I didn’t know the history of ASICBOOST. Our proposal (see Implementation) is to phase in oPoW slowly starting at a very low % of the rewards (say 1%). That should give a long testing period where there is real financial incentive for things like ASICBOOST
Does that resolve or partially resolve the issue in your eyes? Sent from my iPhone > On May 18, 2021, at 7:36 AM, ZmnSCPxj <zmnsc...@protonmail.com> wrote: > > Good morning Michael, > >> That’s a fair point about patents. However, note that we were careful about >> this. oPoW only uses SHA3 (can be replaced with SHA256 in principle as well) >> and low precision linear matrix multiplication. A whole industry is trying >> to accelerate 8-bit linear matrix mults for AI so there is already a massive >> incentive (and has been for decades). >> >> See companies like Mythic, Groq, Tesla (FSD computer), google TPU and so on >> for electronic versions of this. Several of the optical ones are mentioned >> in the BIP (e.g. Lightmatter) > > > Please note that ASICBOOST for SHA256d is based on a layer-crossing > violation: SHA256 processes in blocks, and the Bitcoin block header is > slightly larger than one SHA256 block. > > Adding more to a direct SHA3 (which, as a "sponge" construction, avoids > blocks, but other layer-crossing violations may still exist) still risks > layer violations that might introduce hidden optimizations. > > Or more succinctly; > > * Just because the components have (with high probability) no more possible > optimizations, does not mean that the construction *as a whole* has no hidden > optimizations. > > Thus, even if linear matrix multiplication and SHA3 have no hidden > optimizations, their combination, together with the Bitcoin block header > format, *may* have hidden optimizations. > > And there are no *current* incentives to find such optimizations until > Bitcoin moves to this, at which point we are already committed and it would > be highly infeasible to revert to SHA256d --- i.e. too late. > > This is why changes to PoW are highly discouraged. > > > Remember, ASICBOOST was *not* an optimization of SHA256 *or* SHA256d, it was > an optimizations of SHA256d-on-a-Bitcoin-block-header. > ASICBOOST cannot speed up general SHA256 or even general SHA256d, it only > applies specifically to SHA256d-on-a-Bitcoin-block-header. > > Regards, > ZmnSCPxj _______________________________________________ bitcoin-dev mailing list bitcoin-dev@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
