Circuit

1. Write circom circuit
2. Compile the circuit: circom simple_multiplier.circom --r1cs --wasm --sym
3. Download a powers of tau trusted setup file
4. Run Plonk setup to get the proving key: snarkjs plonk setup circuit.r1cs ptau_file.ptau proving_key.zkey

To generate zkey: snarkjs plonk setup simple_multiplier/simple_multiplier.r1cs ptau/powersOfTau28_hez_final_08.ptau simple_multiplier/proving_key.zkey