rust-poseidon2-bn254

Rust implementation of the Poseidon2 hash function over the BN254 curve's scalar field, with permutation state width t=3.

We plan to integrate this into Plonky2, to allow an efficient BN254 recursive wrapper. For this we need some custom features: For example when computing the Fiat-Shamir challenges, we need a duplex construction which can absorb and squeeze both BN254 and Goldilocks field elements.

Currently using arkworks for field arithmetic (maybe replace it with something more light-weight in the future...)