Merge pull request #63 from Yoii-Inc/fix/role_assignment_r1cs

Fix/role assignment r1cs

.github/workflows/rust_ci.yml

@@ -254,4 +254,7 @@ jobs:
         run: ./run_werewolf.zsh night
 
       - name: Run werewolf vote
-        run: ./run_werewolf.zsh vote
+        run: ./run_werewolf.zsh vote
+
+      - name: Run werewolf role assignment
+        run: ./run_werewolf.zsh role_assignment

examples/bin_werewolf.rs

@@ -385,6 +385,7 @@ fn role_assignment(opt: &Opt) -> Result<(), std::io::Error> {
     // prove
     let local_role_circuit = RoleAssignmentCircuit {
         num_players: n,
+        max_group_size: grouping_parameter.get_max_group_size(),
         pedersen_param: pedersen_param.clone(),
         tau_matrix: na::DMatrix::<Fr>::zeros(n + m, n + m),
         shuffle_matrices: vec![na::DMatrix::<Fr>::zeros(n + m, n + m); 2],
@@ -420,6 +421,7 @@ fn role_assignment(opt: &Opt) -> Result<(), std::io::Error> {
 
     let mpc_role_circuit = RoleAssignmentCircuit {
         num_players: n,
+        max_group_size: grouping_parameter.get_max_group_size(),
         pedersen_param: mpc_pedersen_param,
         tau_matrix: grouping_parameter.generate_tau_matrix(),
         shuffle_matrices: shuffle_matrix,
@@ -622,6 +624,14 @@ impl GroupingParameter {
         self.0.values().map(|x| x.0).sum()
     }
 
+    fn get_max_group_size(&self) -> usize {
+        self.0
+            .values()
+            .map(|(count, is_not_alone)| if *is_not_alone { *count } else { 1 })
+            .max()
+            .expect("Error: No max value found")
+    }
+
     fn get_corresponding_role(&self, role_id: usize) -> Roles {
         let mut count = self.get_num_players();
         for (role, (role_count, is_not_alone)) in self.0.iter() {

src/circuits/werewolf.rs

@@ -855,6 +855,7 @@ impl ConstraintSynthesizer<mm::MpcField<Fr>> for WinningJudgeCircuit<mm::MpcFiel
 pub struct RoleAssignmentCircuit<F: PrimeField + LocalOrMPC<F>> {
     // parameter
     pub num_players: usize,
+    pub max_group_size: usize,
     pub pedersen_param: F::PedersenParam,
 
     // instance
@@ -961,7 +962,7 @@ impl ConstraintSynthesizer<Fr> for RoleAssignmentCircuit<Fr> {
 
         let calced_role = calced_vec
             .iter()
-            .map(|val| test_max(val, false).unwrap())
+            .map(|val| test_max(val, self.max_group_size + 1, true).unwrap())
             .collect::<Vec<_>>();
 
         // commitment
@@ -1077,7 +1078,7 @@ impl ConstraintSynthesizer<mm::MpcField<Fr>> for RoleAssignmentCircuit<mm::MpcFi
 
         let calced_role = calced_vec
             .iter()
-            .map(|val| test_max_mpc(val, false).unwrap())
+            .map(|val| test_max_mpc(val, self.max_group_size + 1, true).unwrap())
             .collect::<Vec<_>>();
 
         // commitment
@@ -1328,8 +1329,10 @@ impl ElGamalLocalOrMPC<mm::MpcField<Fr>> for mm::MpcField<Fr> {
     }
 }
 
+// return maximum value in the vector a, index runs from 0 to use_index_len
 fn test_max<F: PrimeField>(
     a: &[FpVar<F>],
+    use_index_len: usize,
     should_enforce: bool,
 ) -> Result<FpVar<F>, SynthesisError> {
     let cs = a[0].cs().clone();
@@ -1340,18 +1343,17 @@ fn test_max<F: PrimeField>(
 
     if should_enforce {
         // each element must be less than half of the modulus
-        a.iter().for_each(|x| {
-            max_var
-                .enforce_cmp(x, core::cmp::Ordering::Greater, true)
-                .unwrap()
-        });
+        for i in 0..use_index_len {
+            a[i].enforce_cmp(&max_var, core::cmp::Ordering::Less, true)?;
+        }
     }
 
     Ok(max_var)
 }
 
 fn test_max_mpc<F: PrimeField + SquareRootField + BitDecomposition + EqualityZero>(
     a: &[MpcFpVar<F>],
+    use_index_len: usize,
     should_enforce: bool,
 ) -> Result<MpcFpVar<F>, SynthesisError> {
     let cs = a[0].cs().clone();
@@ -1361,12 +1363,9 @@ fn test_max_mpc<F: PrimeField + SquareRootField + BitDecomposition + EqualityZer
     })?;
 
     if should_enforce {
-        // [ ]: implement correctly
-        a.iter().for_each(|x| {
-            max_var
-                .enforce_cmp(x, core::cmp::Ordering::Greater, true)
-                .unwrap()
-        });
+        for i in 0..use_index_len {
+            a[i].enforce_cmp(&max_var, core::cmp::Ordering::Less, true)?;
+        }
     }
 
     Ok(max_var)
@@ -1533,10 +1532,9 @@ where
             // all check 0 or 1 -> row sum and column sum is 1
             let val = &matrix[(i, j)];
 
-            (<MpcFpVar<F> as Zero>::zero() - val)
-                .is_zero()
+            val.is_zero()
                 .unwrap()
-                .or(&(<MpcFpVar<F> as One>::one() - val).is_zero().unwrap())
+                .or(&(val - <MpcFpVar<F> as One>::one()).is_zero().unwrap())
                 .unwrap()
                 .enforce_equal(&MpcBoolean::TRUE)?;