diff --git a/src/gro16/prover.c b/src/gro16/prover.c
index 7ed8874..e62d4ac 100644
--- a/src/gro16/prover.c
+++ b/src/gro16/prover.c
@@ -92,7 +92,7 @@ void h_coefficients(proving_key *pk)
     ifft(n, pk->wMFr, AsFr);
 }
 
-void mul_exp(struct mulExpResult *result, mpz_t *uwProof, proving_key *pk)
+void mul_exp(struct mulExpResult *result, mclBnFr *uwProof, proving_key *pk)
 {
     int n = mpz_get_ui(pk->Ne);
 
@@ -101,7 +101,7 @@ void mul_exp(struct mulExpResult *result, mpz_t *uwProof, proving_key *pk)
 
     for (int i = nConst; i < (nPublic + nConst); i++)
     {
-        mpz_set(uwProof[i-nConst], uw[i]);
+        mpz_to_fr(&uwProof[i-nConst], &uw[i]);
     }
 
     #pragma omp parallel for
@@ -124,7 +124,7 @@ void mul_exp(struct mulExpResult *result, mpz_t *uwProof, proving_key *pk)
     mclBnG1_mulVecMT(&result->htdelta, pk->xt1_rand, AsFr, n, num_threads);
 }
 
-void prove(int *circuit, mclBnG1 *piA, mclBnG2 *piB2, mclBnG1 *piC, mpz_t *uwProof, proving_key *pk)
+void prove(int *circuit, mclBnG1 *piA, mclBnG2 *piB2, mclBnG1 *piC, mclBnFr *uwProof, proving_key *pk)
 {
     prover = 1;
 
diff --git a/src/gro16/verifier.c b/src/gro16/verifier.c
index 6f0acaf..3aec82c 100644
--- a/src/gro16/verifier.c
+++ b/src/gro16/verifier.c
@@ -10,8 +10,7 @@ int verify(proof *p, verifying_key *vk)
     for (int i = (nPublic); i--;)
     {
         // Vu = Vu + u[i] * s1.vk[i]
-        mpz_to_fr(&frFactor, &p->uwProof[i]);
-        mclBnG1_mul(&factorG1, &vk->vk1[i+nConst], &frFactor);
+        mclBnG1_mul(&factorG1, &vk->vk1[i+nConst], &p->uwProof[i]);
         mclBnG1_add(&Vu, &Vu, &factorG1);
     }
 
diff --git a/src/zpie.c b/src/zpie.c
index c5dc287..bf69cb2 100644
--- a/src/zpie.c
+++ b/src/zpie.c
@@ -382,12 +382,7 @@ proof generate_proof(void *circuit, proving_key *pk)
     
     proof p;
 
-    p.uwProof = (mpz_t*) malloc((nPublic) * sizeof(mpz_t));
-
-    for (int i = 0; i < (nPublic); i++)
-    {
-        mpz_init(p.uwProof[i]);
-    }
+    p.uwProof = (mclBnFr*) malloc((nPublic) * sizeof(mclBnFr));
 
     if (bench) printf("--- Computing proof...\n");
     struct timespec begin, end;
@@ -427,14 +422,14 @@ void store_proof(proof *p)
     FILE *fproof;
     fproof = fopen("data/proof.params", "w");
 
+    int size = 0;
+
     for (int i = 0; i < (nPublic); i++)
     {
-        mpz_out_raw(fproof, p->uwProof[i]);
+        size += mclBnFr_serialize(buff + size, SIZE_FR, &p->uwProof[i]);
     }
 
-    int size = 0;
-
-    size += mclBnG1_serialize(buff, SIZE_G1, &p->piA);
+    size += mclBnG1_serialize(buff + size, SIZE_G1, &p->piA);
     size += mclBnG2_serialize(buff + size, SIZE_G2, &p->piB2);
     size += mclBnG1_serialize(buff + size, SIZE_G1, &p->piC);
 
@@ -450,18 +445,18 @@ proof read_proof()
     FILE *fproof;
     fproof = fopen("data/proof.params", "r");
 
-    p.uwProof = (mpz_t*) malloc((nPublic) * sizeof(mpz_t));
+    p.uwProof = (mclBnFr*) malloc((nPublic) * sizeof(mclBnFr));
+
+    int size = 0;
+
+    fread(buff, 1, (SIZE_FR * nPublic) + SIZE_G1 + SIZE_G2 + SIZE_G1, fproof);
 
     for (int i = 0; i < (nPublic); i++)
     {
-        mpz_init(p.uwProof[i]);
-        mpz_inp_raw(p.uwProof[i], fproof);
+        size += mclBnFr_deserialize(&p.uwProof[i], buff + size, SIZE_FR);
     }
 
-    int size = 0;
-
-    fread(buff, 1, SIZE_G1 + SIZE_G2 + SIZE_G1, fproof);
-    size += mclBnG1_deserialize(&p.piA, buff, SIZE_G1);
+    size += mclBnG1_deserialize(&p.piA, buff + size, SIZE_G1);
     size += mclBnG2_deserialize(&p.piB2, buff + size, SIZE_G2);
     size += mclBnG1_deserialize(&p.piC, buff + size, SIZE_G1);
 
diff --git a/src/zpie.h b/src/zpie.h
index aa5108b..f2e0a32 100644
--- a/src/zpie.h
+++ b/src/zpie.h
@@ -69,7 +69,7 @@ typedef struct
 
 typedef struct
 {
-    mpz_t *uwProof;
+    mclBnFr *uwProof;
     mclBnG1 piA, piC;
     mclBnG2 piB2;
 } proof;