New layer of curves

[simonmasson]

Using Poseidon with bls12_377::ScalarField is not very efficient because we are restricted to α=11. In the case of bls12_381::ScalarField, we have α=5 (but we cannot have a 2-layer with this curve). This bigger α increases the circuit with a factor between 2 to 10. In order to fix this, we would need to find a new 2-layer of curves where:

• gcd(p_bls-1, 3 or 5) = 1
• gcd(r_bls-1, 3 or 5) = 1
• gcd(r_bw-1, 3 or 5) = 1

This is more a research work of generation of curves.