Relax Arc requirement for parameters (tari-project#102)

This PR relaxes the `Arc` requirement for parameters. Specifically, it removes the requirement that the caller use an `Arc` wrapper for `TriptychParameters`. Instead, this wrapping is handled internally. Closes tari-project#65. BREAKING CHANGE: Updates the public API.
AaronFeickert · Aug 9, 2024 · fc3682c · fc3682c
1 parent 078b0b7
commit fc3682c
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Showing 13 changed files with 40 additions and 61 deletions.
diff --git a/benches/parallel.rs b/benches/parallel.rs
@@ -5,9 +5,6 @@
 
 #[macro_use]
 extern crate criterion;
-extern crate alloc;
-
-use alloc::sync::Arc;
 
 use criterion::{BatchSize, Criterion};
 use curve25519_dalek::{RistrettoPoint, Scalar};
@@ -33,7 +30,7 @@ const BATCH_SIZES: [usize; 1] = [2];
 #[allow(non_snake_case)]
 #[allow(clippy::arithmetic_side_effects)]
 fn generate_data<R: CryptoRngCore>(
-    params: &Arc<TriptychParameters>,
+    params: &TriptychParameters,
     b: usize,
     rng: &mut R,
 ) -> (Vec<TriptychWitness>, Vec<TriptychStatement>, Vec<Transcript>) {
@@ -94,7 +91,7 @@ fn generate_proof(c: &mut Criterion) {
     for n in N_VALUES {
         for m in M_VALUES {
             // Generate parameters
-            let params = Arc::new(TriptychParameters::new(n, m).unwrap());
+            let params = TriptychParameters::new(n, m).unwrap();
 
             let label = format!("Generate proof: n = {}, m = {} (N = {})", n, m, params.get_N());
             group.bench_function(&label, |b| {
@@ -125,7 +122,7 @@ fn generate_proof_vartime(c: &mut Criterion) {
     for n in N_VALUES {
         for m in M_VALUES {
             // Generate parameters
-            let params = Arc::new(TriptychParameters::new(n, m).unwrap());
+            let params = TriptychParameters::new(n, m).unwrap();
 
             let label = format!(
                 "Generate proof (variable time): n = {}, m = {} (N = {})",
@@ -161,7 +158,7 @@ fn verify_proof(c: &mut Criterion) {
     for n in N_VALUES {
         for m in M_VALUES {
             // Generate parameters
-            let params = Arc::new(TriptychParameters::new(n, m).unwrap());
+            let params = TriptychParameters::new(n, m).unwrap();
 
             let label = format!("Verify proof: n = {}, m = {} (N = {})", n, m, params.get_N());
             group.bench_function(&label, |b| {
@@ -197,7 +194,7 @@ fn verify_batch_proof(c: &mut Criterion) {
     for n in N_VALUES {
         for m in M_VALUES {
             // Generate parameters
-            let params = Arc::new(TriptychParameters::new(n, m).unwrap());
+            let params = TriptychParameters::new(n, m).unwrap();
 
             for batch in BATCH_SIZES {
                 let label = format!(

diff --git a/benches/triptych.rs b/benches/triptych.rs
@@ -5,9 +5,6 @@
 
 #[macro_use]
 extern crate criterion;
-extern crate alloc;
-
-use alloc::sync::Arc;
 
 use criterion::{BatchSize, Criterion};
 use curve25519_dalek::{RistrettoPoint, Scalar};
@@ -31,7 +28,7 @@ const BATCH_SIZES: [usize; 1] = [2];
 #[allow(non_snake_case)]
 #[allow(clippy::arithmetic_side_effects)]
 fn generate_data<R: CryptoRngCore>(
-    params: &Arc<TriptychParameters>,
+    params: &TriptychParameters,
     b: usize,
     rng: &mut R,
 ) -> (Vec<TriptychWitness>, Vec<TriptychStatement>, Vec<Transcript>) {
@@ -84,7 +81,7 @@ fn generate_proof(c: &mut Criterion) {
     for n in N_VALUES {
         for m in M_VALUES {
             // Generate parameters
-            let params = Arc::new(TriptychParameters::new(n, m).unwrap());
+            let params = TriptychParameters::new(n, m).unwrap();
 
             let label = format!("Generate proof: n = {}, m = {} (N = {})", n, m, params.get_N());
             group.bench_function(&label, |b| {
@@ -115,7 +112,7 @@ fn generate_proof_vartime(c: &mut Criterion) {
     for n in N_VALUES {
         for m in M_VALUES {
             // Generate parameters
-            let params = Arc::new(TriptychParameters::new(n, m).unwrap());
+            let params = TriptychParameters::new(n, m).unwrap();
 
             let label = format!(
                 "Generate proof (variable time): n = {}, m = {} (N = {})",
@@ -151,7 +148,7 @@ fn verify_proof(c: &mut Criterion) {
     for n in N_VALUES {
         for m in M_VALUES {
             // Generate parameters
-            let params = Arc::new(TriptychParameters::new(n, m).unwrap());
+            let params = TriptychParameters::new(n, m).unwrap();
 
             let label = format!("Verify proof: n = {}, m = {} (N = {})", n, m, params.get_N());
             group.bench_function(&label, |b| {
@@ -187,7 +184,7 @@ fn verify_batch_proof(c: &mut Criterion) {
     for n in N_VALUES {
         for m in M_VALUES {
             // Generate parameters
-            let params = Arc::new(TriptychParameters::new(n, m).unwrap());
+            let params = TriptychParameters::new(n, m).unwrap();
 
             for batch in BATCH_SIZES {
                 let label = format!(

diff --git a/examples/ringct.rs b/examples/ringct.rs
@@ -10,8 +10,6 @@
 //! This example shows how to use Triptych.
 #[cfg(test)]
 mod test {
-    use std::sync::Arc;
-
     use curve25519_dalek::{RistrettoPoint, Scalar};
     use merlin::Transcript;
     use rand_chacha::ChaCha12Rng;
@@ -25,10 +23,9 @@ mod test {
         let mut rng = ChaCha12Rng::seed_from_u64(8675309);
 
         // Parameters that will define the number of outputs used in the proof: 2^4 == 16
-        // The parameters are `Arc`-wrapped since it's likely they could be reused
         let n = 2;
         let m = 4;
-        let params = Arc::new(TriptychParameters::new(n, m).unwrap());
+        let params = TriptychParameters::new(n, m).unwrap();
         let number_outputs = params.get_N();
 
         // Value commitments use the Triptych `G` generator for masks, and need another component for values

diff --git a/src/lib.rs b/src/lib.rs
@@ -67,20 +67,16 @@
 //! ```
 //! # #[cfg(feature = "rand")]
 //! # {
-//! # extern crate alloc;
-//! use alloc::sync::Arc;
-//!
 //! use curve25519_dalek::RistrettoPoint;
 //! use rand_core::OsRng;
 //! use triptych::*;
 //!
 //! let mut rng = OsRng;
 //!
 //! // Generate parameters
-//! // This is `Arc`-wrapped to facilitate efficient reuse!
 //! const n: u32 = 2;
 //! const m: u32 = 3;
-//! let params = Arc::new(TriptychParameters::new(n, m).unwrap());
+//! let params = TriptychParameters::new(n, m).unwrap();
 //!
 //! // Generate a random witness, which includes the signing key and an index where it will appear
 //! let witness = TriptychWitness::random(&params, &mut rng);

diff --git a/src/parallel/mod.rs b/src/parallel/mod.rs
@@ -21,20 +21,16 @@
 //! ```
 //! # #[cfg(feature = "rand")]
 //! # {
-//! # extern crate alloc;
-//! use alloc::sync::Arc;
-//!
 //! use curve25519_dalek::{RistrettoPoint, Scalar};
 //! use rand_core::OsRng;
 //! use triptych::{parallel::*, Transcript};
 //!
 //! let mut rng = OsRng;
 //!
 //! // Generate parameters
-//! // This is `Arc`-wrapped to facilitate efficient reuse!
 //! const n: u32 = 2;
 //! const m: u32 = 3;
-//! let params = Arc::new(TriptychParameters::new(n, m).unwrap());
+//! let params = TriptychParameters::new(n, m).unwrap();
 //!
 //! // Generate a random witness, which includes the signing key, auxiliary key, and an index where they will appear
 //! let witness = TriptychWitness::random(&params, &mut rng);

diff --git a/src/parallel/parameters.rs b/src/parallel/parameters.rs
@@ -1,7 +1,7 @@
 // Copyright (c) 2024, The Tari Project
 // SPDX-License-Identifier: BSD-3-Clause
 
-use alloc::{vec, vec::Vec};
+use alloc::{sync::Arc, vec, vec::Vec};
 use core::iter::once;
 
 use blake3::Hasher;
@@ -29,7 +29,7 @@ pub struct TriptychParameters {
     G: RistrettoPoint,
     G1: RistrettoPoint,
     U: RistrettoPoint,
-    CommitmentG: Vec<RistrettoPoint>,
+    CommitmentG: Arc<Vec<RistrettoPoint>>,
     CommitmentH: RistrettoPoint,
     hash: Vec<u8>,
 }
@@ -149,7 +149,7 @@ impl TriptychParameters {
             G: *G,
             G1: *G1,
             U: *U,
-            CommitmentG,
+            CommitmentG: Arc::new(CommitmentG),
             CommitmentH,
             hash,
         })

diff --git a/src/parallel/proof.rs b/src/parallel/proof.rs
@@ -1022,7 +1022,7 @@ impl BorshDeserialize for TriptychProof {
 
 #[cfg(test)]
 mod test {
-    use alloc::{sync::Arc, vec::Vec};
+    use alloc::vec::Vec;
 
     use curve25519_dalek::{traits::Identity, RistrettoPoint, Scalar};
     use itertools::izip;
@@ -1061,7 +1061,7 @@ mod test {
         rng: &mut R,
     ) -> (Vec<TriptychWitness>, Vec<TriptychStatement>, Vec<Transcript>) {
         // Generate parameters
-        let params = Arc::new(TriptychParameters::new(n, m).unwrap());
+        let params = TriptychParameters::new(n, m).unwrap();
 
         // Generate witnesses; for this test, we use adjacent indexes for simplicity
         // This means the batch size must not exceed the input set size!
@@ -1090,7 +1090,7 @@ mod test {
             offsets.push(r_offset * params.get_G1());
             M1[witness.get_l() as usize] = witness.compute_auxiliary_verification_key() + offsets.last().unwrap();
         }
-        let input_set = Arc::new(TriptychInputSet::new(&M, &M1).unwrap());
+        let input_set = TriptychInputSet::new(&M, &M1).unwrap();
 
         // Generate statements
         let mut statements = Vec::with_capacity(b);
@@ -1375,7 +1375,7 @@ mod test {
         let M1 = statements[0].get_input_set().get_auxiliary_keys().to_vec();
         let index = ((witnesses[0].get_l() + 1) % witnesses[0].get_params().get_N()) as usize;
         M[index] = RistrettoPoint::random(&mut rng);
-        let evil_input_set = Arc::new(TriptychInputSet::new(&M, &M1).unwrap());
+        let evil_input_set = TriptychInputSet::new(&M, &M1).unwrap();
         let evil_statement = TriptychStatement::new(
             statements[0].get_params(),
             &evil_input_set,
@@ -1407,7 +1407,7 @@ mod test {
         let mut M1 = statements[0].get_input_set().get_auxiliary_keys().to_vec();
         let index = ((witnesses[0].get_l() + 1) % witnesses[0].get_params().get_N()) as usize;
         M1[index] = RistrettoPoint::random(&mut rng);
-        let evil_input_set = Arc::new(TriptychInputSet::new(&M, &M1).unwrap());
+        let evil_input_set = TriptychInputSet::new(&M, &M1).unwrap();
         let evil_statement = TriptychStatement::new(
             statements[0].get_params(),
             &evil_input_set,

diff --git a/src/parallel/statement.rs b/src/parallel/statement.rs
@@ -129,7 +129,7 @@ impl TriptychInputSet {
 #[allow(non_snake_case)]
 #[derive(Clone, Eq, PartialEq)]
 pub struct TriptychStatement {
-    params: Arc<TriptychParameters>,
+    params: TriptychParameters,
     input_set: TriptychInputSet,
     offset: RistrettoPoint,
     J: RistrettoPoint,
@@ -161,7 +161,7 @@ impl TriptychStatement {
     /// otherwise provided externally.
     #[allow(non_snake_case)]
     pub fn new(
-        params: &Arc<TriptychParameters>,
+        params: &TriptychParameters,
         input_set: &TriptychInputSet,
         offset: &RistrettoPoint,
         J: &RistrettoPoint,
@@ -203,7 +203,7 @@ impl TriptychStatement {
     }
 
     /// Get the parameters for this [`TriptychStatement`].
-    pub fn get_params(&self) -> &Arc<TriptychParameters> {
+    pub fn get_params(&self) -> &TriptychParameters {
         &self.params
     }
 

diff --git a/src/parallel/witness.rs b/src/parallel/witness.rs
@@ -1,8 +1,6 @@
 // Copyright (c) 2024, The Tari Project
 // SPDX-License-Identifier: BSD-3-Clause
 
-use alloc::sync::Arc;
-
 use curve25519_dalek::{RistrettoPoint, Scalar};
 use rand_core::CryptoRngCore;
 use snafu::prelude::*;
@@ -18,7 +16,7 @@ use crate::parallel::TriptychParameters;
 #[derive(Zeroize, ZeroizeOnDrop)]
 pub struct TriptychWitness {
     #[zeroize(skip)]
-    params: Arc<TriptychParameters>,
+    params: TriptychParameters,
     l: u32,
     r: Scalar,
     r1: Scalar,
@@ -40,7 +38,7 @@ impl TriptychWitness {
     ///
     /// If you'd like a [`TriptychWitness`] generated securely for you, use [`TriptychWitness::random`] instead.
     #[allow(non_snake_case)]
-    pub fn new(params: &Arc<TriptychParameters>, l: u32, r: &Scalar, r1: &Scalar) -> Result<Self, WitnessError> {
+    pub fn new(params: &TriptychParameters, l: u32, r: &Scalar, r1: &Scalar) -> Result<Self, WitnessError> {
         if r == &Scalar::ZERO || r1 == &Scalar::ZERO {
             return Err(WitnessError::InvalidParameter);
         }
@@ -63,7 +61,7 @@ impl TriptychWitness {
     ///
     /// If you'd rather provide your own secret data, use [`TriptychWitness::new`] instead.
     #[allow(clippy::cast_possible_truncation)]
-    pub fn random<R: CryptoRngCore>(params: &Arc<TriptychParameters>, rng: &mut R) -> Self {
+    pub fn random<R: CryptoRngCore>(params: &TriptychParameters, rng: &mut R) -> Self {
         // Generate a random index using wide reduction
         // This can't truncate since `N` is bounded by `u32`
         // It is also defined since `N > 0`
@@ -79,7 +77,7 @@ impl TriptychWitness {
     }
 
     /// Get the [`TriptychParameters`] from this [`TriptychWitness`].
-    pub fn get_params(&self) -> &Arc<TriptychParameters> {
+    pub fn get_params(&self) -> &TriptychParameters {
         &self.params
     }
 

diff --git a/src/parameters.rs b/src/parameters.rs
@@ -1,7 +1,7 @@
 // Copyright (c) 2024, The Tari Project
 // SPDX-License-Identifier: BSD-3-Clause
 
-use alloc::{vec, vec::Vec};
+use alloc::{sync::Arc, vec, vec::Vec};
 use core::iter::once;
 
 use blake3::Hasher;
@@ -28,7 +28,7 @@ pub struct TriptychParameters {
     m: u32,
     G: RistrettoPoint,
     U: RistrettoPoint,
-    CommitmentG: Vec<RistrettoPoint>,
+    CommitmentG: Arc<Vec<RistrettoPoint>>,
     CommitmentH: RistrettoPoint,
     hash: Vec<u8>,
 }
@@ -132,7 +132,7 @@ impl TriptychParameters {
             m,
             G: *G,
             U: *U,
-            CommitmentG,
+            CommitmentG: Arc::new(CommitmentG),
             CommitmentH,
             hash,
         })

diff --git a/src/proof.rs b/src/proof.rs
@@ -941,7 +941,7 @@ impl BorshDeserialize for TriptychProof {
 
 #[cfg(test)]
 mod test {
-    use alloc::{sync::Arc, vec::Vec};
+    use alloc::vec::Vec;
 
     use curve25519_dalek::{traits::Identity, RistrettoPoint, Scalar};
     use itertools::izip;
@@ -978,7 +978,7 @@ mod test {
         rng: &mut R,
     ) -> (Vec<TriptychWitness>, Vec<TriptychStatement>, Vec<Transcript>) {
         // Generate parameters
-        let params = Arc::new(TriptychParameters::new(n, m).unwrap());
+        let params = TriptychParameters::new(n, m).unwrap();
 
         // Generate witnesses; for this test, we use adjacent indexes for simplicity
         // This means the batch size must not exceed the input set size!

diff --git a/src/statement.rs b/src/statement.rs
@@ -98,7 +98,7 @@ impl TriptychInputSet {
 #[allow(non_snake_case)]
 #[derive(Clone, Eq, PartialEq)]
 pub struct TriptychStatement {
-    params: Arc<TriptychParameters>,
+    params: TriptychParameters,
     input_set: TriptychInputSet,
     J: RistrettoPoint,
     hash: Vec<u8>,
@@ -129,7 +129,7 @@ impl TriptychStatement {
     /// otherwise provided externally.
     #[allow(non_snake_case)]
     pub fn new(
-        params: &Arc<TriptychParameters>,
+        params: &TriptychParameters,
         input_set: &TriptychInputSet,
         J: &RistrettoPoint,
     ) -> Result<Self, StatementError> {
@@ -159,7 +159,7 @@ impl TriptychStatement {
     }
 
     /// Get the parameters for this [`TriptychStatement`].
-    pub fn get_params(&self) -> &Arc<TriptychParameters> {
+    pub fn get_params(&self) -> &TriptychParameters {
         &self.params
     }