diff --git a/phase2/src/bin/export_keys.rs b/phase2/src/bin/export_keys.rs
index bc41091..90cafa2 100644
--- a/phase2/src/bin/export_keys.rs
+++ b/phase2/src/bin/export_keys.rs
@@ -6,9 +6,12 @@ extern crate serde;
 extern crate serde_json;
 extern crate num_bigint;
 extern crate num_traits;
+extern crate itertools;
 
 use std::fs;
 use std::fs::OpenOptions;
+use std::iter::repeat;
+use itertools::Itertools;
 use serde::{Deserialize, Serialize};
 use phase2::parameters::MPCParameters;
 use phase2::utils::{
@@ -74,84 +77,31 @@ fn main() {
     let params = MPCParameters::read(reader, disallow_points_at_infinity, true).expect("unable to read params");
     let params = params.get_params();
 
-    let mut proving_key = ProvingKeyJson {
-        a: vec![],
-        b1: vec![],
-        b2: vec![],
-        c: vec![],
-        vk_alfa_1: vec![],
-        vk_beta_1: vec![],
-        vk_delta_1: vec![],
-        vk_beta_2: vec![],
-        vk_delta_2: vec![],
-        h: vec![],
+    let proving_key = ProvingKeyJson {
+        a: params.a.iter().map(|e| p1_to_vec(e)).collect_vec(),
+        b1: params.b_g1.iter().map(|e| p1_to_vec(e)).collect_vec(),
+        b2: params.b_g2.iter().map(|e| p2_to_vec(e)).collect_vec(),
+        c: repeat(None).take(params.vk.ic.len()).chain(params.l.iter().map(|e| Some(p1_to_vec(e)))).collect_vec(),
+        vk_alfa_1: p1_to_vec(&params.vk.alpha_g1),
+        vk_beta_1: p1_to_vec(&params.vk.beta_g1),
+        vk_delta_1: p1_to_vec(&params.vk.delta_g1),
+        vk_beta_2: p2_to_vec(&params.vk.beta_g2),
+        vk_delta_2: p2_to_vec(&params.vk.delta_g2),
+        h: params.h.iter().map(|e| p1_to_vec(e)).collect_vec(),
     };
 
-    let a = params.a.clone();
-    for e in a.iter() {
-        proving_key.a.push(p1_to_vec(e));
-    }
-    let b1 = params.b_g1.clone();
-    for e in b1.iter() {
-        proving_key.b1.push(p1_to_vec(e));
-    }
-    let b2 = params.b_g2.clone();
-    for e in b2.iter() {
-        proving_key.b2.push(p2_to_vec(e));
-    }
-    let c = params.l.clone();
-    for _ in 0..params.vk.ic.len() {
-        proving_key.c.push(None);
-    }
-    for e in c.iter() {
-        proving_key.c.push(Some(p1_to_vec(e)));
-    }
-
-    let vk_alfa_1 = params.vk.alpha_g1.clone();
-    proving_key.vk_alfa_1 = p1_to_vec(&vk_alfa_1);
-
-    let vk_beta_1 = params.vk.beta_g1.clone();
-    proving_key.vk_beta_1 = p1_to_vec(&vk_beta_1);
-
-    let vk_delta_1 = params.vk.delta_g1.clone();
-    proving_key.vk_delta_1 = p1_to_vec(&vk_delta_1);
-
-    let vk_beta_2 = params.vk.beta_g2.clone();
-    proving_key.vk_beta_2 = p2_to_vec(&vk_beta_2);
-
-    let vk_delta_2 = params.vk.delta_g2.clone();
-    proving_key.vk_delta_2 = p2_to_vec(&vk_delta_2);
-
-    let h = params.h.clone();
-    for e in h.iter() {
-        proving_key.h.push(p1_to_vec(e));
-    }
-
-    let mut verification_key = VerifyingKeyJson {
-        ic: vec![],
-        vk_alfa_1: vec![],
-        vk_beta_2: vec![],
-        vk_gamma_2: vec![],
-        vk_delta_2: vec![],
-        vk_alfabeta_12: vec![],
+    let verification_key = VerifyingKeyJson {
+        ic: params.vk.ic.iter().map(|e| p1_to_vec(e)).collect_vec(),
+        vk_alfa_1: p1_to_vec(&params.vk.alpha_g1),
+        vk_beta_2: p2_to_vec(&params.vk.beta_g2),
+        vk_gamma_2: p2_to_vec(&params.vk.gamma_g2),
+        vk_delta_2: p2_to_vec(&params.vk.delta_g2),
+        vk_alfabeta_12: pairing_to_vec(&Bn256::pairing(params.vk.alpha_g1, params.vk.beta_g2)),
     };
 
-    let ic = params.vk.ic.clone();
-    for e in ic.iter() {
-        verification_key.ic.push(p1_to_vec(e));
-    }
-
-    verification_key.vk_alfa_1 = p1_to_vec(&vk_alfa_1);
-    verification_key.vk_beta_2 = p2_to_vec(&vk_beta_2);
-    let vk_gamma_2 = params.vk.gamma_g2.clone();
-    verification_key.vk_gamma_2 = p2_to_vec(&vk_gamma_2);
-    verification_key.vk_delta_2 = p2_to_vec(&vk_delta_2);
-    verification_key.vk_alfabeta_12 = pairing_to_vec(&Bn256::pairing(vk_alfa_1, vk_beta_2));
-
     let pk_json = serde_json::to_string(&proving_key).unwrap();
-    fs::write(pk_filename, pk_json.as_bytes()).unwrap();
-
     let vk_json = serde_json::to_string(&verification_key).unwrap();
+    fs::write(pk_filename, pk_json.as_bytes()).unwrap();
     fs::write(vk_filename, vk_json.as_bytes()).unwrap();
 
     println!("Created {} and {}.", pk_filename, vk_filename);
diff --git a/phase2/src/bin/generate_verifier.rs b/phase2/src/bin/generate_verifier.rs
index d114f20..bc2bb54 100644
--- a/phase2/src/bin/generate_verifier.rs
+++ b/phase2/src/bin/generate_verifier.rs
@@ -12,6 +12,7 @@ use std::fs;
 use std::fs::OpenOptions;
 use num_bigint::BigUint;
 use num_traits::Num;
+use phase2::utils::repr_to_big;
 use phase2::parameters::MPCParameters;
 use bellman_ce::pairing::{
     Engine,
@@ -43,9 +44,6 @@ fn main() {
     let params = MPCParameters::read(reader, should_filter_points_at_infinity, true).expect("unable to read params");
     let vk = &params.get_params().vk;
 
-    let repr_to_big = |r| {
-        BigUint::from_str_radix(&format!("{}", r)[2..], 16).unwrap().to_str_radix(10)
-    };
     let p1_to_str = |p: &<Bn256 as Engine>::G1Affine| {
         let x = repr_to_big(p.get_x().into_repr());
         let y = repr_to_big(p.get_y().into_repr());
diff --git a/phase2/src/bin/prove.rs b/phase2/src/bin/prove.rs
index 90a4755..2c32299 100644
--- a/phase2/src/bin/prove.rs
+++ b/phase2/src/bin/prove.rs
@@ -4,10 +4,12 @@ extern crate exitcode;
 extern crate serde;
 extern crate num_bigint;
 extern crate num_traits;
+extern crate itertools;
 
 use std::fs;
 use std::fs::OpenOptions;
 use serde::{Deserialize, Serialize};
+use itertools::Itertools;
 use phase2::parameters::MPCParameters;
 use phase2::circom_circuit::CircomCircuit;
 use phase2::utils::{
@@ -78,10 +80,7 @@ fn main() {
     let proof_json = serde_json::to_string(&proof).unwrap();
     fs::write(proof_filename, proof_json.as_bytes()).unwrap();
 
-    let mut public_inputs = vec![];
-    for x in input[1..].iter() {
-        public_inputs.push(repr_to_big(x.into_repr()));
-    }
+    let public_inputs = input[1..].iter().map(|x| repr_to_big(x.into_repr())).collect_vec();
     let public_json = serde_json::to_string(&public_inputs).unwrap();
     fs::write(public_filename, public_json.as_bytes()).unwrap();
 
diff --git a/phase2/src/circom_circuit.rs b/phase2/src/circom_circuit.rs
index d981e21..00e4c4d 100644
--- a/phase2/src/circom_circuit.rs
+++ b/phase2/src/circom_circuit.rs
@@ -6,6 +6,7 @@ use std::str;
 use std::fs;
 use std::fs::OpenOptions;
 use std::collections::BTreeMap;
+use itertools::Itertools;
 use std::io::{
     Read,
     Write,
@@ -83,18 +84,13 @@ impl<'a, E: Engine> CircomCircuit<E> {
         let num_inputs = circuit_json.num_inputs + circuit_json.num_outputs + 1;
         let num_aux = circuit_json.num_variables - num_inputs;
 
-        fn convert_constraint<EE: Engine>(lc: &BTreeMap<String, String>) -> Vec<(usize, EE::Fr)> {
-            let mut coeffs = vec![];
-            for (var_index_str, coefficient_str) in lc {
-                coeffs.push((var_index_str.parse().unwrap(), EE::Fr::from_str(coefficient_str).unwrap()));
-            }
-            return coeffs;
-        }
+        let convert_constraint = |lc: &BTreeMap<String, String>| {
+            lc.iter().map(|(index, coeff)| (index.parse().unwrap(), E::Fr::from_str(coeff).unwrap())).collect_vec()
+        };
 
-        let mut constraints = vec![];
-        for constraint in circuit_json.constraints.iter() {
-            constraints.push((convert_constraint::<E>(&constraint[0]), convert_constraint::<E>(&constraint[1]), convert_constraint::<E>(&constraint[2])));
-        }
+        let constraints = circuit_json.constraints.iter().map(
+            |c| (convert_constraint(&c[0]), convert_constraint(&c[1]), convert_constraint(&c[2]))
+        ).collect_vec();
 
         return CircomCircuit {
             num_inputs: num_inputs,
@@ -130,23 +126,22 @@ impl<'a, E: Engine> Circuit<E> for CircomCircuit<E> {
             })?;
         }
 
-        fn make_lc<E: Engine>(lc_data: Vec<(usize, E::Fr)>, num_inputs: usize) -> LinearCombination<E> {
-            let mut lc = LinearCombination::<E>::zero();
-            for (index, coeff) in lc_data {
-                let var_index = if index < num_inputs {
-                    Index::Input(index)
-                } else {
-                    Index::Aux(index - num_inputs)
-                };
-                lc = lc + (coeff, Variable::new_unchecked(var_index))
-            }
-            return lc;
-        }
+        let make_index = |index|
+            if index < self.num_inputs {
+                Index::Input(index)
+            } else {
+                Index::Aux(index - self.num_inputs)
+            };
+        let make_lc = |lc_data: Vec<(usize, E::Fr)>|
+            lc_data.iter().fold(
+                LinearCombination::<E>::zero(),
+                |lc: LinearCombination<E>, (index, coeff)| lc + (*coeff, Variable::new_unchecked(make_index(*index)))
+            );
         for (i, constraint) in self.constraints.iter().enumerate() {
             cs.enforce(|| format!("constraint {}", i),
-                       |_| make_lc(constraint.0.clone(), self.num_inputs),
-                       |_| make_lc(constraint.1.clone(), self.num_inputs),
-                       |_| make_lc(constraint.2.clone(), self.num_inputs),
+                       |_| make_lc(constraint.0.clone()),
+                       |_| make_lc(constraint.1.clone()),
+                       |_| make_lc(constraint.2.clone()),
             );
         }
         Ok(())
diff --git a/phase2/src/lib.rs b/phase2/src/lib.rs
index 83d23e5..a6cdd47 100644
--- a/phase2/src/lib.rs
+++ b/phase2/src/lib.rs
@@ -11,6 +11,8 @@ extern crate crossbeam;
 extern crate num_bigint;
 extern crate num_traits;
 extern crate cfg_if;
+extern crate itertools;
+
 use cfg_if::cfg_if;
 
 pub mod keypair;