Adding a constructor for ParamsKZG

[Ethan-000]

Hey

I'm wondering if a ParamsKZG constructor can be added so that it can be initialized through k, n, g, g_lagrange, g2, s_g2 🙂. Currently these fields are only accessible through the crate and there's no function that can do this

    pub(crate) k: u32,
    pub(crate) n: u64,
    pub(crate) g: Vec<E::G1Affine>,
    pub(crate) g_lagrange: Vec<E::G1Affine>,
    pub(crate) g2: E::G2Affine,
    pub(crate) s_g2: E::G2Affine,

[CPerezz]

Sure! I don't see any reason why this could not be done. But I'm not sure why the current usage options don't fit you.
You can currently do to things:

• You can generate parameters and serialize them into a file. And read them when you need to.
• Generate the params on the fly (this works for small sizes only, but should help depending on the setup).

Why any of these two things doesn't work for you? What are you trying to do?

[Ethan-000]

Yeah I was trying to initialize the parameters from an existing setup ceremony

[Ethan-000]

I can try to open a pr that add this functionality if thats okay :)

[CPerezz]

Yeah I was trying to initialize the parameters from an existing setup ceremony

Ohh I see.
Basically you have the powers of Tau but not in the format we need them for you to serialize the object. Is that the case?

If so, if you want to make a PR, we definitely appreciate it! Otherwise, we'll try to implement this as soon as we have time for it! 😄

[Ethan-000]

Ohh I see. Basically you have the powers of Tau but not in the format we need them for you to serialize the object. Is that the case?

Yep

If so, if you want to make a PR, we definitely appreciate it! Otherwise, we'll try to implement this as soon as we have time for it! 😄

Will do later today 🫡

[kilic]

Why any of these two things doesn't work for you? What are you trying to do?

Other option is that to make a file that halo2 can deserialize so that we can ensure that parameters can pass assertions while reading

[han0110]

Yeah I was trying to initialize the parameters from an existing setup ceremony

btw for reading from existing ceremony, we also have some format converted already in this repo https://github.com/han0110/halo2-kzg-srs (currently we have converted https://github.com/weijiekoh/perpetualpowersoftau and https://github.com/iden3/snarkjs).

[Ethan-000]

Yeah I was trying to initialize the parameters from an existing setup ceremony

btw for reading from existing ceremony, we also have some format converted already in this repo https://github.com/han0110/halo2-kzg-srs (currently we have converted https://github.com/weijiekoh/perpetualpowersoftau and https://github.com/iden3/snarkjs).

Great will have a look 🙂