move from rug to num-bigint (#53)

Cargo.toml

@@ -1,8 +1,8 @@
 [package]
 name = "nova-snark"
-version = "0.4.2"
+version = "0.5.0"
 authors = ["Srinath Setty <srinath@microsoft.com>"]
-edition = "2018"
+edition = "2021"
 description = "Recursive zkSNARKs without trusted setup"
 documentation = "https://docs.rs/nova-snark/"
 readme = "README.md"
@@ -25,8 +25,9 @@ subtle = "2.4"
 pasta_curves = "0.3.1"
 neptune = "6.1"
 generic-array = "0.14.4"
-bellperson-nonnative = { version = "0.2.1", default-features = false, features = ["wasm"] }
-rug = { version = "1.10", default-features = false, features = ["integer", "serde", "rand"] }
+bellperson-nonnative = { version = "0.3.0", default-features = false, features = ["wasm"] }
+num-bigint = { version = "0.4", features = ["serde", "rand"] }
+num-traits = "0.2"
 serde = { version = "1.0", features = ["derive"] }
 bincode = "1.2.1"
 flate2 = "1.0"

src/gadgets/utils.rs

@@ -10,7 +10,7 @@ use bellperson::{
 };
 use bellperson_nonnative::mp::bignat::{nat_to_limbs, BigNat};
 use ff::{Field, PrimeField, PrimeFieldBits};
-use rug::Integer;
+use num_bigint::BigInt;
 
 /// Gets as input the little indian representation of a number and spits out the number
 #[allow(dead_code)]
@@ -116,7 +116,7 @@ pub fn scalar_as_base(input: G::Scalar) -> G::Base {
 /// Allocate bignat a constant
 pub fn alloc_bignat_constant<F: PrimeField, CS: ConstraintSystem<F>>(
   mut cs: CS,
-  val: &Integer,
+  val: &BigInt,
   limb_width: usize,
   n_limbs: usize,
 ) -> Result<BigNat<F>, SynthesisError> {

src/pasta.rs

@@ -6,6 +6,8 @@ use crate::{
 use core::ops::Mul;
 use ff::Field;
 use merlin::Transcript;
+use num_bigint::BigInt;
+use num_traits::Num;
 use pasta_curves::{
   self,
   arithmetic::{CurveAffine, CurveExt, Group as Grp},
@@ -14,7 +16,6 @@ use pasta_curves::{
 };
 use rand::SeedableRng;
 use rand_chacha::ChaCha20Rng;
-use rug::Integer;
 
 //////////////////////////////////////Pallas///////////////////////////////////////////////
 
@@ -75,8 +76,8 @@ impl Group for pallas::Point {
     }
   }
 
-  fn get_order() -> Integer {
-    Integer::from_str_radix(
+  fn get_order() -> BigInt {
+    BigInt::from_str_radix(
       "40000000000000000000000000000000224698fc0994a8dd8c46eb2100000001",
       16,
     )
@@ -163,8 +164,8 @@ impl Group for vesta::Point {
     }
   }
 
-  fn get_order() -> Integer {
-    Integer::from_str_radix(
+  fn get_order() -> BigInt {
+    BigInt::from_str_radix(
       "40000000000000000000000000000000224698fc094cf91b992d30ed00000001",
       16,
     )

src/traits.rs

@@ -6,7 +6,7 @@ use core::{
 };
 use ff::{PrimeField, PrimeFieldBits};
 use merlin::Transcript;
-use rug::Integer;
+use num_bigint::BigInt;
 
 /// Represents an element of a group
 pub trait Group:
@@ -53,7 +53,7 @@ pub trait Group:
   fn to_coordinates(&self) -> (Self::Base, Self::Base, bool);
 
   /// Returns the order of the group as a big integer
-  fn get_order() -> Integer;
+  fn get_order() -> BigInt;
 }
 
 /// Represents a compressed version of a group element

tests/nonnative.rs

@@ -9,11 +9,12 @@ use nova_snark::bellperson::{
   shape_cs::ShapeCS,
   solver::SatisfyingAssignment,
 };
-use rug::Integer;
+use num_bigint::BigInt;
+use num_traits::Num as OtherNum;
 
 fn synthesize_is_equal<Fr: PrimeField, CS: ConstraintSystem<Fr>>(
   cs: &mut CS,
-  a_val: &Integer,
+  a_val: &BigInt,
   limb_width: usize,
   n_limbs: usize,
 ) -> Result<(), SynthesisError> {
@@ -42,11 +43,11 @@ fn synthesize_is_equal>(
 #[allow(clippy::too_many_arguments)]
 fn synthesize_mult_mod<Fr: PrimeField, CS: ConstraintSystem<Fr>>(
   cs: &mut CS,
-  a_val: &Integer,
-  b_val: &Integer,
-  m_val: &Integer,
-  q_val: &Integer,
-  r_val: &Integer,
+  a_val: &BigInt,
+  b_val: &BigInt,
+  m_val: &BigInt,
+  q_val: &BigInt,
+  r_val: &BigInt,
   limb_width: usize,
   n_limbs: usize,
 ) -> Result<(), SynthesisError> {
@@ -93,9 +94,9 @@ fn synthesize_mult_mod>(
 
 fn synthesize_add<Fr: PrimeField, CS: ConstraintSystem<Fr>>(
   cs: &mut CS,
-  a_val: &Integer,
-  b_val: &Integer,
-  c_val: &Integer,
+  a_val: &BigInt,
+  b_val: &BigInt,
+  c_val: &BigInt,
   limb_width: usize,
   n_limbs: usize,
 ) -> Result<(), SynthesisError> {
@@ -126,10 +127,10 @@ fn synthesize_add>(
 
 fn synthesize_add_mod<Fr: PrimeField, CS: ConstraintSystem<Fr>>(
   cs: &mut CS,
-  a_val: &Integer,
-  b_val: &Integer,
-  c_val: &Integer,
-  m_val: &Integer,
+  a_val: &BigInt,
+  b_val: &BigInt,
+  c_val: &BigInt,
+  m_val: &BigInt,
   limb_width: usize,
   n_limbs: usize,
 ) -> Result<(), SynthesisError> {
@@ -170,27 +171,27 @@ fn test_mult_mod() {
   type G = pasta_curves::pallas::Point;
 
   // Set the inputs
-  let a_val = Integer::from_str_radix(
+  let a_val = BigInt::from_str_radix(
     "11572336752428856981970994795408771577024165681374400871001196932361466228192",
     10,
   )
   .unwrap();
-  let b_val = Integer::from_str_radix(
+  let b_val = BigInt::from_str_radix(
     "87673389408848523602668121701204553693362841135953267897017930941776218798802",
     10,
   )
   .unwrap();
-  let m_val = Integer::from_str_radix(
+  let m_val = BigInt::from_str_radix(
     "40000000000000000000000000000000224698fc094cf91b992d30ed00000001",
     16,
   )
   .unwrap();
-  let q_val = Integer::from_str_radix(
+  let q_val = BigInt::from_str_radix(
     "35048542371029440058224000662033175648615707461806414787901284501179083518342",
     10,
   )
   .unwrap();
-  let r_val = Integer::from_str_radix(
+  let r_val = BigInt::from_str_radix(
     "26362617993085418618858432307761590013874563896298265114483698919121453084730",
     10,
   )
@@ -217,13 +218,13 @@ fn test_add() {
   type G = pasta_curves::pallas::Point;
 
   // Set the inputs
-  let a_val = Integer::from_str_radix(
+  let a_val = BigInt::from_str_radix(
     "11572336752428856981970994795408771577024165681374400871001196932361466228192",
     10,
   )
   .unwrap();
-  let b_val = Integer::from_str_radix("1", 10).unwrap();
-  let c_val = Integer::from_str_radix(
+  let b_val = BigInt::from_str_radix("1", 10).unwrap();
+  let c_val = BigInt::from_str_radix(
     "11572336752428856981970994795408771577024165681374400871001196932361466228193",
     10,
   )
@@ -250,18 +251,18 @@ fn test_add_mod() {
   type G = pasta_curves::pallas::Point;
 
   // Set the inputs
-  let a_val = Integer::from_str_radix(
+  let a_val = BigInt::from_str_radix(
     "11572336752428856981970994795408771577024165681374400871001196932361466228192",
     10,
   )
   .unwrap();
-  let b_val = Integer::from_str_radix("1", 10).unwrap();
-  let c_val = Integer::from_str_radix(
+  let b_val = BigInt::from_str_radix("1", 10).unwrap();
+  let c_val = BigInt::from_str_radix(
     "11572336752428856981970994795408771577024165681374400871001196932361466228193",
     10,
   )
   .unwrap();
-  let m_val = Integer::from_str_radix(
+  let m_val = BigInt::from_str_radix(
     "40000000000000000000000000000000224698fc094cf91b992d30ed00000001",
     16,
   )
@@ -288,7 +289,7 @@ fn test_equal() {
   type G = pasta_curves::pallas::Point;
 
   // Set the inputs
-  let a_val = Integer::from_str_radix("1157233675242885698197099479540877", 10).unwrap();
+  let a_val = BigInt::from_str_radix("1157233675242885698197099479540877", 10).unwrap();
 
   // First create the shape
   let mut cs: ShapeCS<G> = ShapeCS::new();