refactor: Refactor public parameters setup to remove optionality of c…

…ommitment key size hint (#95)

* refactor: Refactor public parameters setup to remove optionality of commitment key size hint

- Converted `CommitmentKeyHint<G>` from a boxed dynamic trait object to a direct dynamic trait object in `r1cs/mod.rs`.
- Changed the `commitment_key` function to always require a commitment key floor, eliminating the need for default behavior when a floor function isn't provided.
- Updated the `r1cs_shape` function across various files to take in a `CommitmentKeyHint` instead of it being optional and introduce a closure as an argument.
- Relevant modifications and updates were made in the `r1cs_shape` and `commitment_key` function calls within the test functions for various modules.
- Ported use of commitment key hint to Supernova, closing #53.
- This PR puts Arecibo in line with microsoft/Nova#203

* doc: document Supernova Public Parameters

- Enhanced the `PublicParams` struct within `./src/supernova/mod.rs` with detailed comments

* feat: Refactor to use `default_commitment_key_hint` across codebase

- Introduced a new function `default_commitment_key_hint` in `nova_snark` package to provide a clearer default sizing hint for the commitment key,
- Replaced hard-coded zero values throughout the codebase with calls to `default_commitment_key_hint` function,

benches/compressed-snark.rs

@@ -69,8 +69,8 @@ fn bench_compressed_snark(c: &mut Criterion) {
     let pp = PublicParams::<G1, G2, C1, C2>::new(
       &c_primary,
       &c_secondary,
-      Some(S1::commitment_key_floor()),
-      Some(S2::commitment_key_floor()),
+      &*S1::commitment_key_floor(),
+      &*S2::commitment_key_floor(),
     );
 
     // Produce prover and verifier keys for CompressedSNARK
@@ -156,8 +156,8 @@ fn bench_compressed_snark_with_computational_commitments(c: &mut Criterion) {
     let pp = PublicParams::<G1, G2, C1, C2>::new(
       &c_primary,
       &c_secondary,
-      Some(SS1::commitment_key_floor()),
-      Some(SS2::commitment_key_floor()),
+      &*SS1::commitment_key_floor(),
+      &*SS2::commitment_key_floor(),
     );
     // Produce prover and verifier keys for CompressedSNARK
     let (pk, vk) = CompressedSNARK::<_, _, _, _, SS1, SS2>::setup(&pp).unwrap();

benches/compute-digest.rs

@@ -6,6 +6,7 @@ use ff::PrimeField;
 use nova_snark::{
   traits::{
     circuit::{StepCircuit, TrivialCircuit},
+    snark::default_commitment_key_hint,
     Group,
   },
   PublicParams,
@@ -30,8 +31,8 @@ fn bench_compute_digest(c: &mut Criterion) {
       PublicParams::<G1, G2, C1, C2>::new(
         black_box(&C1::new(10)),
         black_box(&C2::default()),
-        black_box(None),
-        black_box(None),
+        black_box(&*default_commitment_key_hint()),
+        black_box(&*default_commitment_key_hint()),
       )
     })
   });

benches/recursive-snark-supernova.rs

@@ -9,6 +9,7 @@ use nova_snark::{
   supernova::{PublicParams, RecursiveSNARK},
   traits::{
     circuit_supernova::{StepCircuit, TrivialTestCircuit},
+    snark::default_commitment_key_hint,
     Group,
   },
 };
@@ -104,7 +105,11 @@ fn bench_one_augmented_circuit_recursive_snark(c: &mut Criterion) {
 
     let bench: NonUniformBench<G1, G2, TrivialTestCircuit<<G2 as Group>::Scalar>> =
       NonUniformBench::new(1, num_cons);
-    let pp = PublicParams::new(&bench);
+    let pp = PublicParams::new(
+      &bench,
+      &*default_commitment_key_hint(),
+      &*default_commitment_key_hint(),
+    );
 
     // Bench time to produce a recursive SNARK;
     // we execute a certain number of warm-up steps since executing
@@ -206,7 +211,11 @@ fn bench_two_augmented_circuit_recursive_snark(c: &mut Criterion) {
 
     let bench: NonUniformBench<G1, G2, TrivialTestCircuit<<G2 as Group>::Scalar>> =
       NonUniformBench::new(2, num_cons);
-    let pp = PublicParams::new(&bench);
+    let pp = PublicParams::new(
+      &bench,
+      &*default_commitment_key_hint(),
+      &*default_commitment_key_hint(),
+    );
 
     // Bench time to produce a recursive SNARK;
     // we execute a certain number of warm-up steps since executing

benches/recursive-snark.rs

@@ -7,6 +7,7 @@ use ff::PrimeField;
 use nova_snark::{
   traits::{
     circuit::{StepCircuit, TrivialCircuit},
+    snark::default_commitment_key_hint,
     Group,
   },
   PublicParams, RecursiveSNARK,
@@ -56,7 +57,12 @@ fn bench_recursive_snark(c: &mut Criterion) {
     let c_secondary = TrivialCircuit::default();
 
     // Produce public parameters
-    let pp = PublicParams::<G1, G2, C1, C2>::new(&c_primary, &c_secondary, None, None);
+    let pp = PublicParams::<G1, G2, C1, C2>::new(
+      &c_primary,
+      &c_secondary,
+      &*default_commitment_key_hint(),
+      &*default_commitment_key_hint(),
+    );
 
     // Bench time to produce a recursive SNARK;
     // we execute a certain number of warm-up steps since executing

benches/sha256.rs

@@ -17,6 +17,7 @@ use ff::{PrimeField, PrimeFieldBits};
 use nova_snark::{
   traits::{
     circuit::{StepCircuit, TrivialCircuit},
+    snark::default_commitment_key_hint,
     Group,
   },
   PublicParams, RecursiveSNARK,
@@ -155,7 +156,12 @@ fn bench_recursive_snark(c: &mut Criterion) {
 
     // Produce public parameters
     let ttc = TrivialCircuit::default();
-    let pp = PublicParams::<G1, G2, C1, C2>::new(&circuit_primary, &ttc, None, None);
+    let pp = PublicParams::<G1, G2, C1, C2>::new(
+      &circuit_primary,
+      &ttc,
+      &*default_commitment_key_hint(),
+      &*default_commitment_key_hint(),
+    );
 
     let circuit_secondary = TrivialCircuit::default();
     let z0_primary = vec![<G1 as Group>::Scalar::from(2u64)];

examples/minroot.rs

@@ -9,6 +9,7 @@ use flate2::{write::ZlibEncoder, Compression};
 use nova_snark::{
   traits::{
     circuit::{StepCircuit, TrivialCircuit},
+    snark::default_commitment_key_hint,
     Group,
   },
   CompressedSNARK, PublicParams, RecursiveSNARK,
@@ -169,7 +170,12 @@ fn main() {
       G2,
       MinRootCircuit<<G1 as Group>::Scalar>,
       TrivialCircuit<<G2 as Group>::Scalar>,
-    >::new(&circuit_primary, &circuit_secondary, None, None);
+    >::new(
+      &circuit_primary,
+      &circuit_secondary,
+      &*default_commitment_key_hint(),
+      &*default_commitment_key_hint(),
+    );
     println!("PublicParams::setup, took {:?} ", start.elapsed());
 
     println!(

examples/minroot_serde.rs

@@ -12,6 +12,7 @@ use ff::PrimeField;
 use nova_snark::{
   traits::{
     circuit::{StepCircuit, TrivialCircuit},
+    snark::default_commitment_key_hint,
     Group,
   },
   PublicParams,
@@ -167,7 +168,12 @@ fn main() {
       G2,
       MinRootCircuit<<G1 as Group>::Scalar>,
       TrivialCircuit<<G2 as Group>::Scalar>,
-    >::new(&circuit_primary, &circuit_secondary, None, None);
+    >::new(
+      &circuit_primary,
+      &circuit_secondary,
+      &*default_commitment_key_hint(),
+      &*default_commitment_key_hint(),
+    );
     println!("PublicParams::setup, took {:?} ", start.elapsed());
     encode(&pp, &mut file).unwrap()
   };
@@ -193,7 +199,12 @@ fn main() {
       G2,
       MinRootCircuit<<G1 as Group>::Scalar>,
       TrivialCircuit<<G2 as Group>::Scalar>,
-    >::new(&circuit_primary, &circuit_secondary, None, None);
+    >::new(
+      &circuit_primary,
+      &circuit_secondary,
+      &*default_commitment_key_hint(),
+      &*default_commitment_key_hint(),
+    );
     assert!(result.clone() == pp, "not equal!");
     assert!(remaining.is_empty());
   } else {

src/bellpepper/mod.rs

@@ -15,7 +15,7 @@ mod tests {
       shape_cs::ShapeCS,
       solver::SatisfyingAssignment,
     },
-    traits::Group,
+    traits::{snark::default_commitment_key_hint, Group},
   };
   use bellpepper_core::{num::AllocatedNum, ConstraintSystem, SynthesisError};
   use ff::PrimeField;
@@ -50,7 +50,7 @@ mod tests {
     // First create the shape
     let mut cs: ShapeCS<G> = ShapeCS::new();
     let _ = synthesize_alloc_bit(&mut cs);
-    let (shape, ck) = cs.r1cs_shape_and_key(None);
+    let (shape, ck) = cs.r1cs_shape_and_key(&*default_commitment_key_hint());
 
     // Now get the assignment
     let mut cs: SatisfyingAssignment<G> = SatisfyingAssignment::new();

src/bellpepper/r1cs.rs

@@ -25,15 +25,11 @@ pub trait NovaWitness<G: Group> {
 /// `NovaShape` provides methods for acquiring `R1CSShape` and `CommitmentKey` from implementers.
 pub trait NovaShape<G: Group> {
   /// Return an appropriate `R1CSShape` and `CommitmentKey` structs.
-  /// Optionally, a `CommitmentKeyHint` can be provided to help guide the
-  /// construction of the `CommitmentKey`. This parameter is documented in
-  /// `r1cs::R1CS::commitment_key`.
-  fn r1cs_shape_and_key(
-    &self,
-    optfn: Option<CommitmentKeyHint<G>>,
-  ) -> (R1CSShape<G>, CommitmentKey<G>) {
+  /// A `CommitmentKeyHint` should be provided to help guide the construction of the `CommitmentKey`.
+  /// This parameter is documented in `r1cs::R1CS::commitment_key`.
+  fn r1cs_shape_and_key(&self, ck_hint: &CommitmentKeyHint<G>) -> (R1CSShape<G>, CommitmentKey<G>) {
     let S = self.r1cs_shape();
-    let ck = commitment_key(&S, optfn);
+    let ck = commitment_key(&S, ck_hint);
 
     (S, ck)
   }

src/circuit.rs

@@ -368,6 +368,7 @@ mod tests {
 
   use crate::constants::{BN_LIMB_WIDTH, BN_N_LIMBS};
   use crate::provider;
+  use crate::traits::snark::default_commitment_key_hint;
   use crate::{
     bellpepper::r1cs::{NovaShape, NovaWitness},
     gadgets::utils::scalar_as_base,
@@ -393,7 +394,7 @@ mod tests {
       NovaAugmentedCircuit::new(primary_params, None, &tc1, ro_consts1.clone());
     let mut cs: TestShapeCS<G1> = TestShapeCS::new();
     let _ = circuit1.synthesize(&mut cs);
-    let (shape1, ck1) = cs.r1cs_shape_and_key(None);
+    let (shape1, ck1) = cs.r1cs_shape_and_key(&*default_commitment_key_hint());
     assert_eq!(cs.num_constraints(), num_constraints_primary);
 
     let tc2 = TrivialCircuit::default();
@@ -402,7 +403,7 @@ mod tests {
       NovaAugmentedCircuit::new(secondary_params, None, &tc2, ro_consts2.clone());
     let mut cs: TestShapeCS<G2> = TestShapeCS::new();
     let _ = circuit2.synthesize(&mut cs);
-    let (shape2, ck2) = cs.r1cs_shape_and_key(None);
+    let (shape2, ck2) = cs.r1cs_shape_and_key(&*default_commitment_key_hint());
     assert_eq!(cs.num_constraints(), num_constraints_secondary);
 
     // Execute the base case for the primary

src/gadgets/ecc.rs

@@ -748,14 +748,17 @@ where
 #[cfg(test)]
 mod tests {
   use super::*;
-  use crate::bellpepper::{
-    r1cs::{NovaShape, NovaWitness},
-    {solver::SatisfyingAssignment, test_shape_cs::TestShapeCS},
-  };
   use crate::provider::{
     bn256_grumpkin::{bn256, grumpkin},
     secp_secq::{secp256k1, secq256k1},
   };
+  use crate::{
+    bellpepper::{
+      r1cs::{NovaShape, NovaWitness},
+      {solver::SatisfyingAssignment, test_shape_cs::TestShapeCS},
+    },
+    traits::snark::default_commitment_key_hint,
+  };
   use ff::{Field, PrimeFieldBits};
   use pasta_curves::{arithmetic::CurveAffine, group::Curve, pallas, vesta};
   use rand::rngs::OsRng;
@@ -1001,7 +1004,7 @@ mod tests {
     let mut cs: TestShapeCS<G2> = TestShapeCS::new();
     let _ = synthesize_smul::<G1, _>(cs.namespace(|| "synthesize"));
     println!("Number of constraints: {}", cs.num_constraints());
-    let (shape, ck) = cs.r1cs_shape_and_key(None);
+    let (shape, ck) = cs.r1cs_shape_and_key(&*default_commitment_key_hint());
 
     // Then the satisfying assignment
     let mut cs: SatisfyingAssignment<G2> = SatisfyingAssignment::new();
@@ -1057,7 +1060,7 @@ mod tests {
     let mut cs: TestShapeCS<G2> = TestShapeCS::new();
     let _ = synthesize_add_equal::<G1, _>(cs.namespace(|| "synthesize add equal"));
     println!("Number of constraints: {}", cs.num_constraints());
-    let (shape, ck) = cs.r1cs_shape_and_key(None);
+    let (shape, ck) = cs.r1cs_shape_and_key(&*default_commitment_key_hint());
 
     // Then the satisfying assignment
     let mut cs: SatisfyingAssignment<G2> = SatisfyingAssignment::new();
@@ -1117,7 +1120,7 @@ mod tests {
     let mut cs: TestShapeCS<G2> = TestShapeCS::new();
     let _ = synthesize_add_negation::<G1, _>(cs.namespace(|| "synthesize add equal"));
     println!("Number of constraints: {}", cs.num_constraints());
-    let (shape, ck) = cs.r1cs_shape_and_key(None);
+    let (shape, ck) = cs.r1cs_shape_and_key(&*default_commitment_key_hint());
 
     // Then the satisfying assignment
     let mut cs: SatisfyingAssignment<G2> = SatisfyingAssignment::new();