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>

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<Base, Scalar> {
 /// 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<G: Group>: 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 {