Various optimizations to protocols to improve performance

Cargo.toml

@@ -33,3 +33,5 @@ itertools = "0.14.0"
 rustls = "0.23"
 num-bigint = "0.4"
 uuid = { version = "1.18.1", features = ["v4", "v5", "serde"] }
+dashmap = "6.1"
+crossbeam = "0.8"

mpc/Cargo.toml

@@ -29,10 +29,17 @@ stoffelnet.workspace = true
 rustls.workspace = true
 num-bigint.workspace = true
 uuid.workspace = true
+dashmap.workspace = true
+crossbeam.workspace = true
 
 [dev-dependencies]
 once_cell = "1.21.3"
 tracing-subscriber = { version = "0.3", features = ["env-filter", "fmt"] }
+criterion = { version = "0.5", features = ["html_reports"] }
+
+[[bench]]
+name = "lagrange_benchmark"
+harness = false
 
 [lib]
 crate-type = ["lib", "staticlib", "cdylib"]

mpc/benches/lagrange_benchmark.rs

@@ -0,0 +1,114 @@
+//! Criterion benchmarks for Lagrange interpolation threshold analysis.
+//!
+//! Run with: cargo bench --package stoffelmpc-mpc
+//!
+//! This will generate HTML reports in target/criterion/
+
+use ark_bls12_381::Fr;
+use ark_ff::UniformRand;
+use ark_std::test_rng;
+use criterion::{
+    black_box, criterion_group, criterion_main, BenchmarkId, Criterion, PlotConfiguration,
+    AxisScale,
+};
+use stoffelmpc_mpc::common::{
+    lagrange_interpolate_parallel_exposed, lagrange_interpolate_sequential_exposed,
+};
+
+fn generate_test_data(n: usize) -> (Vec<Fr>, Vec<Fr>) {
+    let mut rng = test_rng();
+    let x_vals: Vec<Fr> = (1..=n).map(|i| Fr::from(i as u64)).collect();
+    let y_vals: Vec<Fr> = (0..n).map(|_| Fr::rand(&mut rng)).collect();
+    (x_vals, y_vals)
+}
+
+fn bench_sequential(c: &mut Criterion) {
+    let mut group = c.benchmark_group("lagrange_sequential");
+
+    for n in [3, 4, 5, 6, 7, 8, 10, 12, 15, 20, 25, 30] {
+        let (x_vals, y_vals) = generate_test_data(n);
+
+        group.bench_with_input(BenchmarkId::from_parameter(n), &n, |b, _| {
+            b.iter(|| {
+                lagrange_interpolate_sequential_exposed(black_box(&x_vals), black_box(&y_vals))
+            })
+        });
+    }
+
+    group.finish();
+}
+
+fn bench_parallel(c: &mut Criterion) {
+    let mut group = c.benchmark_group("lagrange_parallel");
+
+    for n in [3, 4, 5, 6, 7, 8, 10, 12, 15, 20, 25, 30] {
+        let (x_vals, y_vals) = generate_test_data(n);
+
+        group.bench_with_input(BenchmarkId::from_parameter(n), &n, |b, _| {
+            b.iter(|| {
+                lagrange_interpolate_parallel_exposed(black_box(&x_vals), black_box(&y_vals))
+            })
+        });
+    }
+
+    group.finish();
+}
+
+fn bench_comparison(c: &mut Criterion) {
+    let plot_config = PlotConfiguration::default()
+        .summary_scale(AxisScale::Logarithmic);
+
+    let mut group = c.benchmark_group("lagrange_comparison");
+    group.plot_config(plot_config);
+
+    for n in [3, 4, 5, 6, 7, 8, 10, 12, 15, 20, 25, 30] {
+        let (x_vals, y_vals) = generate_test_data(n);
+
+        group.bench_with_input(BenchmarkId::new("sequential", n), &n, |b, _| {
+            b.iter(|| {
+                lagrange_interpolate_sequential_exposed(black_box(&x_vals), black_box(&y_vals))
+            })
+        });
+
+        group.bench_with_input(BenchmarkId::new("parallel", n), &n, |b, _| {
+            b.iter(|| {
+                lagrange_interpolate_parallel_exposed(black_box(&x_vals), black_box(&y_vals))
+            })
+        });
+    }
+
+    group.finish();
+}
+
+fn bench_threshold_finder(c: &mut Criterion) {
+    let mut group = c.benchmark_group("threshold_finder");
+
+    // Fine-grained analysis around the expected threshold
+    for n in 3..=12 {
+        let (x_vals, y_vals) = generate_test_data(n);
+
+        group.bench_with_input(BenchmarkId::new("seq", n), &n, |b, _| {
+            b.iter(|| {
+                lagrange_interpolate_sequential_exposed(black_box(&x_vals), black_box(&y_vals))
+            })
+        });
+
+        group.bench_with_input(BenchmarkId::new("par", n), &n, |b, _| {
+            b.iter(|| {
+                lagrange_interpolate_parallel_exposed(black_box(&x_vals), black_box(&y_vals))
+            })
+        });
+    }
+
+    group.finish();
+}
+
+criterion_group!(
+    benches,
+    bench_sequential,
+    bench_parallel,
+    bench_comparison,
+    bench_threshold_finder,
+);
+
+criterion_main!(benches);