How to create quadratic constraints?

[DoHoonKim8]

Currently, it seems we cannot create constraints of degree = 2 (multiplication between 2 witness vectors).
Is there an way to support this?

[p-steuer]

Are you using lnp zk proofs or the labrador proofs ?

[DoHoonKim8]

Hello, I was using LaBRADOR proof and couldn't find out the way to create quadratic constraints with LaZer currently.
I was trying to find API for creating quadratic constraints in LaBRADOR repository (either in Dachshund or Chihuahua frontend, which LaZer code is calling via python binding), and realized that LaBRADOR frontends doesn't fully support quadratic constraint. To be more clear, LaBRADOR proving system is implemented to prove quadratic constraint, but there was no part to bake quadratic coefficients of the constraints into the proving system.

I was trying to address this issue by

1. define and export API for baking quadratic coefficients into proving system inside LaBRADOR repository.
2. just add one more python API inside LaZer so that users can use it

I have already done 1) (you can see the work inside here), but should refine API and test for full prove & verify pipeline. (The work is tested only for simple prove & verify which only checks whether the constraints evaluates to 0 correctly)

Since LaZer is the best option for using Lattice-based proving system and as there are many usecases for using LaBRADOR proving system to prove statements (one very promising area is verifiable Fully Homomorphic Encryption), I think supporting quadratic constraints would be really helpful.