feat: KZG gadget options #1568
Description
In #1567 I fixed an edge case for CheckOpeningProof to allow for all inputs. However, we should handle it more carefully in the whole KZG gadget, but this requires adding regression tests, understanding where we need complete formulas etc.
We should also consider that when PLONK sets WithCompleteArithmetic option, then we should set the KZG option to use complete arithmetic. But I think we should be more careful with setting the options not to blow up the constraint sizes. I think it would be better for PLONK side to have options a la:
- WithAllowZeroWitness
- WithAllowZeroSelector (in case for PLONK circuits where selectors are all zeros)
and depending on that we use complete arithmetic where necessary.
We also need to check how this option would affects Linea BW6-in-BN254 recursion, I recall we were quite at 2-adicity limit. But there KZG verification works well right now as we don't hit edge cases (complex inner circuit and non-zero witness).
I'm attaching some starting point for the work in the future