refactor!: with_network_config for ShamirGroth16 doesn't need zkey an…

…ymore

BREAKING CHANGE: Removes the zkey in the said function signature. We needed
it earlier because we had to know domain size, which we now no longer need.

co-circom/co-circom/src/bin/co-circom.rs

@@ -524,7 +524,7 @@ where
                     let public_input = witness_share.public_inputs.clone();
 
                     // connect to network
-                    let prover = ShamirCoGroth16::with_network_config(t, config.network, &zkey)
+                    let prover = ShamirCoGroth16::with_network_config(t, config.network)
                         .context("while building prover")?;
 
                     // execute prover in MPC

co-circom/co-groth16/src/groth16.rs

@@ -495,14 +495,10 @@ where
     P::ScalarField: CircomArkworksPrimeFieldBridge,
 {
     /// Create a new [ShamirCoGroth16] protocol with a given network configuration.
-    pub fn with_network_config(
-        threshold: usize,
-        config: NetworkConfig,
-        zkey: &ZKey<P>,
-    ) -> Result<Self> {
-        let domain_size = 2usize.pow(u32::try_from(zkey.pow).expect("pow fits into u32"));
-        // we need domain_size + 2 + 1 number of corr rand pairs in witness_map_from_matrices (degree_reduce_vec + r and s + 1 for fork)
-        let num_pairs = domain_size + 2 + 1;
+    pub fn with_network_config(threshold: usize, config: NetworkConfig) -> Result<Self> {
+        // we need 2 + 1 number of corr rand pairs. We need the values r/s (1 pair) and 2 muls (2
+        // pairs)
+        let num_pairs = 3;
         let mpc_net = ShamirMpcNet::new(config)?;
         let preprocessing = ShamirPreprocessing::new(threshold, mpc_net, num_pairs)?;
         let mut protocol0 = ShamirProtocol::from(preprocessing);

tests/tests/circom/e2e_tests/shamir.rs

@@ -61,7 +61,7 @@ macro_rules! add_test_impl {
                     threads.push(thread::spawn(move || {
                         let domain_size = 2usize.pow(u32::try_from(zkey.pow).expect("pow fits into u32"));
                         let num_pairs = match stringify!($proof_system) {
-                            "Groth16" => domain_size + 2 + 1,
+                            "Groth16" => 3,
                             "Plonk"=> domain_size * 222 + 15,
                             _ => unreachable!()
                         };