Add serde proof serialization (#123)

* Bump commit.

* Bump commit.

* (WIP) Add serde support

* Minor fixes

* Use neptune const generics

* Use git patches

* Impl serde for CompressedSNARK

* Update dependencies, revert to typenum

* Formatting

* Update bellperson-nonnative patch

* Cleanup

* Remove bellperson-nonnative fork

* Switch back to fil_pasta_curves

* Update forked dependencies

* Cleanup

* Remove unnecessary patch

* Update to lurk-pasta-msm

---------

Co-authored-by: porcuquine <porcuquine@users.noreply.github.com>

Cargo.toml

@@ -21,7 +21,7 @@ rand_core = { version = "0.5", default-features = false }
 rand_chacha = "0.3"
 itertools = "0.9.0"
 subtle = "2.4"
-pasta_curves = { version = "0.4.0", features = ["repr-c"] }
+pasta_curves = { version = "0.5.2", features = ["repr-c", "serde"], package = "fil_pasta_curves" }
 neptune = { version = "8.1.0", default-features = false }
 generic-array = "0.14.4"
 num-bigint = { version = "0.4", features = ["serde", "rand"] }
@@ -34,7 +34,7 @@ bitvec = "1.0"
 byteorder = "1.4.3"
 
 [target.'cfg(any(target_arch = "x86_64", target_arch = "aarch64"))'.dependencies]
-pasta-msm = "0.1.3"
+pasta-msm = { version = "0.1.0", package = "lurk-pasta-msm" }
 
 [dev-dependencies]
 criterion = "0.3.1"

src/circuit.rs

@@ -28,8 +28,9 @@ use bellperson::{
   Circuit, ConstraintSystem, SynthesisError,
 };
 use ff::Field;
+use serde::{Deserialize, Serialize};
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct NovaAugmentedCircuitParams {
   limb_width: usize,
   n_limbs: usize,
@@ -46,7 +47,8 @@ impl NovaAugmentedCircuitParams {
   }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(bound = "")]
 pub struct NovaAugmentedCircuitInputs<G: Group> {
   params: G::Scalar, // Hash(Shape of u2, Gens for u2). Needed for computing the challenge.
   i: G::Base,

src/commitments.rs

@@ -10,19 +10,22 @@ use core::{
 use ff::Field;
 use merlin::Transcript;
 use rayon::prelude::*;
+use serde::{Deserialize, Serialize};
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct CommitGens<G: Group> {
   gens: Vec<G::PreprocessedGroupElement>,
   _p: PhantomData<G>,
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(bound = "")]
 pub struct Commitment<G: Group> {
   pub(crate) comm: G,
 }
 
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(bound = "")]
 pub struct CompressedCommitment<C: CompressedGroup> {
   comm: C,
 }

src/lib.rs

@@ -35,12 +35,15 @@ use nifs::NIFS;
 use r1cs::{
   R1CSGens, R1CSInstance, R1CSShape, R1CSWitness, RelaxedR1CSInstance, RelaxedR1CSWitness,
 };
+use serde::{Deserialize, Serialize};
 use traits::{
   circuit::StepCircuit, snark::RelaxedR1CSSNARKTrait, AbsorbInROTrait, Group, ROConstants,
   ROConstantsCircuit, ROConstantsTrait, ROTrait,
 };
 
 /// A type that holds public parameters of Nova
+#[derive(Serialize, Deserialize)]
+#[serde(bound = "")]
 pub struct PublicParams<G1, G2, C1, C2>
 where
   G1: Group<Base = <G2 as Group>::Scalar>,
@@ -152,7 +155,8 @@ where
 }
 
 /// A SNARK that proves the correct execution of an incremental computation
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Serialize, Deserialize)]
+#[serde(bound = "")]
 pub struct RecursiveSNARK<G1, G2, C1, C2>
 where
   G1: Group<Base = <G2 as Group>::Scalar>,
@@ -497,7 +501,8 @@ where
 }
 
 /// A SNARK that proves the knowledge of a valid `RecursiveSNARK`
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Serialize, Deserialize)]
+#[serde(bound = "")]
 pub struct CompressedSNARK<G1, G2, C1, C2, S1, S2>
 where
   G1: Group<Base = <G2 as Group>::Scalar>,

src/nifs.rs

@@ -10,10 +10,11 @@ use super::{
   traits::{AbsorbInROTrait, Group, ROTrait},
 };
 use core::marker::PhantomData;
+use serde::{Deserialize, Serialize};
 
 /// A SNARK that holds the proof of a step of an incremental computation
 #[allow(clippy::upper_case_acronyms)]
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct NIFS<G: Group> {
   pub(crate) comm_T: CompressedCommitment<G::CompressedGroupElement>,
   _p: PhantomData<G>,

src/pasta.rs

@@ -15,6 +15,7 @@ use pasta_curves::{
   pallas, vesta, Ep, Eq,
 };
 use rand_chacha::{rand_core::SeedableRng, ChaCha20Rng};
+use serde::{Deserialize, Serialize};
 use sha3::Shake256;
 use std::io::Read;
 
@@ -151,7 +152,7 @@ fn cpu_best_multiexp(coeffs: &[C::Scalar], bases: &[C]) -> C::Cu
 //////////////////////////////////////Pallas///////////////////////////////////////////////
 
 /// A wrapper for compressed group elements that come from the pallas curve
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Serialize, Deserialize)]
 pub struct PallasCompressedElementWrapper {
   repr: [u8; 32],
 }
@@ -266,7 +267,7 @@ impl CompressedGroup for PallasCompressedElementWrapper {
 //////////////////////////////////////Vesta////////////////////////////////////////////////
 
 /// A wrapper for compressed group elements that come from the vesta curve
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Serialize, Deserialize)]
 pub struct VestaCompressedElementWrapper {
   repr: [u8; 32],
 }

src/poseidon.rs

@@ -20,9 +20,10 @@ use neptune::{
   },
   Strength,
 };
+use serde::{Deserialize, Serialize};
 
 /// All Poseidon Constants that are used in Nova
-#[derive(Clone)]
+#[derive(Clone, Serialize, Deserialize)]
 pub struct PoseidonConstantsCircuit<Scalar: PrimeField>(PoseidonConstants<Scalar, U24>);
 
 impl<Scalar> ROConstantsTrait<Scalar> for PoseidonConstantsCircuit<Scalar>
@@ -37,6 +38,7 @@ where
 }
 
 /// A Poseidon-based RO to use outside circuits
+#[derive(Serialize, Deserialize)]
 pub struct PoseidonRO<Base, Scalar>
 where
   Base: PrimeField + PrimeFieldBits,
@@ -52,7 +54,7 @@ where
 
 impl<Base, Scalar> ROTrait<Base, Scalar> for PoseidonRO<Base, Scalar>
 where
-  Base: PrimeField + PrimeFieldBits,
+  Base: PrimeField + PrimeFieldBits + Serialize + for<'de> Deserialize<'de>,
   Scalar: PrimeField + PrimeFieldBits,
 {
   type Constants = PoseidonConstantsCircuit<Base>;
@@ -107,6 +109,7 @@ where
 }
 
 /// A Poseidon-based RO gadget to use inside the verifier circuit.
+#[derive(Serialize, Deserialize)]
 pub struct PoseidonROCircuit<Scalar>
 where
   Scalar: PrimeField + PrimeFieldBits,
@@ -120,7 +123,7 @@ where
 
 impl<Scalar> ROCircuitTrait<Scalar> for PoseidonROCircuit<Scalar>
 where
-  Scalar: PrimeField + PrimeFieldBits,
+  Scalar: PrimeField + PrimeFieldBits + Serialize + for<'de> Deserialize<'de>,
 {
   type Constants = PoseidonConstantsCircuit<Scalar>;
 

src/r1cs.rs

@@ -18,13 +18,14 @@ use serde::{Deserialize, Serialize};
 use sha3::{Digest, Sha3_256};
 
 /// Public parameters for a given R1CS
-#[derive(Clone)]
+#[derive(Clone, Serialize, Deserialize)]
+#[serde(bound = "")]
 pub struct R1CSGens<G: Group> {
   pub(crate) gens: CommitGens<G>,
 }
 
 /// A type that holds the shape of the R1CS matrices
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub struct R1CSShape<G: Group> {
   pub(crate) num_cons: usize,
   pub(crate) num_vars: usize,
@@ -36,27 +37,29 @@ pub struct R1CSShape {
 }
 
 /// A type that holds a witness for a given R1CS instance
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub struct R1CSWitness<G: Group> {
   W: Vec<G::Scalar>,
 }
 
 /// A type that holds an R1CS instance
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(bound = "")]
 pub struct R1CSInstance<G: Group> {
   pub(crate) comm_W: Commitment<G>,
   pub(crate) X: Vec<G::Scalar>,
 }
 
 /// A type that holds a witness for a given Relaxed R1CS instance
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub struct RelaxedR1CSWitness<G: Group> {
   pub(crate) W: Vec<G::Scalar>,
   pub(crate) E: Vec<G::Scalar>,
 }
 
 /// A type that holds a Relaxed R1CS instance
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(bound = "")]
 pub struct RelaxedR1CSInstance<G: Group> {
   pub(crate) comm_W: Commitment<G>,
   pub(crate) comm_E: Commitment<G>,

src/spartan_with_ipa_pc/ipa.rs

@@ -6,6 +6,7 @@ use core::{cmp::max, iter};
 use ff::Field;
 use merlin::Transcript;
 use rayon::prelude::*;
+use serde::{Deserialize, Serialize};
 use std::marker::PhantomData;
 
 pub fn inner_product<T>(a: &[T], b: &[T]) -> T
@@ -66,6 +67,7 @@ impl InnerProductWitness {
 }
 
 /// A non-interactive folding scheme (NIFS) for inner product relations
+#[derive(Serialize, Deserialize)]
 pub struct NIFSForInnerProduct<G: Group> {
   cross_term: G::Scalar,
 }
@@ -181,7 +183,7 @@ impl NIFSForInnerProduct {
 }
 
 /// An inner product argument
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
 pub struct InnerProductArgument<G: Group> {
   L_vec: Vec<CompressedCommitment<G::CompressedGroupElement>>,
   R_vec: Vec<CompressedCommitment<G::CompressedGroupElement>>,

src/spartan_with_ipa_pc/mod.rs

@@ -20,9 +20,12 @@ use itertools::concat;
 use merlin::Transcript;
 use polynomial::{EqPolynomial, MultilinearPolynomial, SparsePolynomial};
 use rayon::prelude::*;
+use serde::{Deserialize, Serialize};
 use sumcheck::SumcheckProof;
 
 /// A type that represents the prover's key
+#[derive(Serialize, Deserialize)]
+#[serde(bound = "")]
 pub struct ProverKey<G: Group> {
   gens_r1cs: R1CSGens<G>,
   gens_ipa: CommitGens<G>,
@@ -40,6 +43,8 @@ impl ProverKeyTrait for ProverKey {
 }
 
 /// A type that represents the verifier's key
+#[derive(Serialize, Deserialize)]
+#[serde(bound = "")]
 pub struct VerifierKey<G: Group> {
   gens_r1cs: R1CSGens<G>,
   gens_ipa: CommitGens<G>,
@@ -59,6 +64,8 @@ impl VerifierKeyTrait for VerifierKey {
 /// A succinct proof of knowledge of a witness to a relaxed R1CS instance
 /// The proof is produced using Spartan's combination of the sum-check and
 /// the commitment to a vector viewed as a polynomial commitment
+#[derive(Serialize, Deserialize)]
+#[serde(bound = "")]
 pub struct RelaxedR1CSSNARK<G: Group> {
   sc_proof_outer: SumcheckProof<G>,
   claims_outer: (G::Scalar, G::Scalar, G::Scalar),

src/spartan_with_ipa_pc/sumcheck.rs

@@ -7,8 +7,10 @@ use core::marker::PhantomData;
 use ff::Field;
 use merlin::Transcript;
 use rayon::prelude::*;
+use serde::{Deserialize, Serialize};
 
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(bound = "")]
 pub struct SumcheckProof<G: Group> {
   compressed_polys: Vec<CompressedUniPoly<G>>,
 }
@@ -226,7 +228,7 @@ pub struct UniPoly {
 
 // ax^2 + bx + c stored as vec![a,c]
 // ax^3 + bx^2 + cx + d stored as vec![a,c,d]
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
 pub struct CompressedUniPoly<G: Group> {
   coeffs_except_linear_term: Vec<G::Scalar>,
   _p: PhantomData<G>,

src/traits/mod.rs

@@ -10,6 +10,7 @@ use core::{
 use ff::{PrimeField, PrimeFieldBits};
 use merlin::Transcript;
 use num_bigint::BigInt;
+use serde::{Deserialize, Serialize};
 
 /// Represents an element of a group
 /// This is currently tailored for an elliptic curve group
@@ -25,25 +26,35 @@ pub trait Group:
   + ScalarMulOwned<<Self as Group>::Scalar>
   + Send
   + Sync
+  + Serialize
+  + for<'de> Deserialize<'de>
 {
   /// A type representing an element of the base field of the group
-  type Base: PrimeField + PrimeFieldBits;
+  type Base: PrimeField + PrimeFieldBits + Serialize + for<'de> Deserialize<'de>;
 
   /// A type representing an element of the scalar field of the group
-  type Scalar: PrimeField + PrimeFieldBits + ChallengeTrait + Send + Sync;
+  type Scalar: PrimeField
+    + PrimeFieldBits
+    + ChallengeTrait
+    + Send
+    + Sync
+    + Serialize
+    + for<'de> Deserialize<'de>;
 
   /// A type representing the compressed version of the group element
-  type CompressedGroupElement: CompressedGroup<GroupElement = Self>;
+  type CompressedGroupElement: CompressedGroup<GroupElement = Self>
+    + Serialize
+    + for<'de> Deserialize<'de>;
 
   /// A type representing preprocessed group element
-  type PreprocessedGroupElement: Clone + Send + Sync;
+  type PreprocessedGroupElement: Clone + Send + Sync + Serialize + for<'de> Deserialize<'de>;
 
   /// A type that represents a hash function that consumes elements
   /// from the base field and squeezes out elements of the scalar field
-  type RO: ROTrait<Self::Base, Self::Scalar>;
+  type RO: ROTrait<Self::Base, Self::Scalar> + Serialize + for<'de> Deserialize<'de>;
 
   /// An alternate implementation of Self::RO in the circuit model
-  type ROCircuit: ROCircuitTrait<Self::Base>;
+  type ROCircuit: ROCircuitTrait<Self::Base> + Serialize + for<'de> Deserialize<'de>;
 
   /// A method to compute a multiexponentation
   fn vartime_multiscalar_mul(
@@ -74,9 +85,11 @@ pub trait Group:
 }
 
 /// Represents a compressed version of a group element
-pub trait CompressedGroup: Clone + Copy + Debug + Eq + Sized + Send + Sync + 'static {
+pub trait CompressedGroup:
+  Clone + Copy + Debug + Eq + Sized + Send + Sync + Serialize + for<'de> Deserialize<'de> + 'static
+{
   /// A type that holds the decompressed version of the compressed group element
-  type GroupElement: Group;
+  type GroupElement: Group + Serialize + for<'de> Deserialize<'de>;
 
   /// Decompresses the compressed group element
   fn decompress(&self) -> Option<Self::GroupElement>;
@@ -106,7 +119,12 @@ pub trait ChallengeTrait {
 /// A helper trait that defines the behavior of a hash function that we use as an RO
 pub trait ROTrait<Base, Scalar> {
   /// A type representing constants/parameters associated with the hash function
-  type Constants: ROConstantsTrait<Base> + Clone + Send + Sync;
+  type Constants: ROConstantsTrait<Base>
+    + Clone
+    + Send
+    + Sync
+    + Serialize
+    + for<'de> Deserialize<'de>;
 
   /// Initializes the hash function
   fn new(constants: Self::Constants, num_absorbs: usize) -> Self;
@@ -121,7 +139,12 @@ pub trait ROTrait {
 /// A helper trait that defines the behavior of a hash function that we use as an RO in the circuit model
 pub trait ROCircuitTrait<Base: PrimeField> {
   /// A type representing constants/parameters associated with the hash function
-  type Constants: ROConstantsTrait<Base> + Clone + Send + Sync;
+  type Constants: ROConstantsTrait<Base>
+    + Clone
+    + Send
+    + Sync
+    + Serialize
+    + for<'de> Deserialize<'de>;
 
   /// Initializes the hash function
   fn new(constants: Self::Constants, num_absorbs: usize) -> Self;

src/traits/snark.rs

@@ -5,6 +5,8 @@ use crate::{
   traits::Group,
 };
 
+use serde::{Deserialize, Serialize};
+
 /// A trait that defines the behavior of a zkSNARK's prover key
 pub trait ProverKeyTrait<G: Group>: Send + Sync {
   /// Produces a new prover's key
@@ -18,12 +20,14 @@ pub trait VerifierKeyTrait: Send + Sync {
 }
 
 /// A trait that defines the behavior of a zkSNARK
-pub trait RelaxedR1CSSNARKTrait<G: Group>: Sized + Send + Sync {
+pub trait RelaxedR1CSSNARKTrait<G: Group>:
+  Sized + Send + Sync + Serialize + for<'de> Deserialize<'de>
+{
   /// A type that represents the prover's key
-  type ProverKey: ProverKeyTrait<G>;
+  type ProverKey: ProverKeyTrait<G> + Serialize + for<'de> Deserialize<'de>;
 
   /// A type that represents the verifier's key
-  type VerifierKey: VerifierKeyTrait<G>;
+  type VerifierKey: VerifierKeyTrait<G> + Serialize + for<'de> Deserialize<'de>;
 
   /// Produces a prover key
   fn prover_key(gens: &R1CSGens<G>, S: &R1CSShape<G>) -> Self::ProverKey {