Woohoo - multifolding works!

README.md

@@ -4,7 +4,7 @@
 
 - ✅ Nova folding
 - ✅ HyperNova folding without multifolding (μ = ν = 0)
-- ❌ HyperNova multifolding (μ = ν = 1)
+- ✅ HyperNova multifolding (μ = ν = 1)
 
 ## Reproduce
 
@@ -18,35 +18,32 @@ make run
 _12th Gen Intel® Core™ i7-12800H × 20, 32Gb RAM_
 
 ```
-Prepare circuit: 62.569µs
-Prepare input: 12.271114ms
+Prepare circuit: 386.733µs
+Prepare input: 9.041434ms
 ========== Nova folding scheme ====================
-Prepare folding: 1.038241793s
-Transform input: 293.007µs
-Prove_step 0: 186.297898ms
-Prove_step 1: 216.137291ms
-Prove_step 2: 244.387123ms
-Prove_step 3: 253.724876ms
-Prove_step 4: 249.476304ms
-Prove_step 5: 254.825831ms
-Folding verification: 15.513019ms
+Prepare folding: 1.042210402s
+Transform input: 352.973µs
+Prove_step 0: 188.311556ms
+Prove_step 1: 201.33003ms
+Prove_step 2: 256.05521ms
+Prove_step 3: 282.359763ms
+Prove_step 4: 252.831315ms
+Prove_step 5: 255.913864ms
+Folding verification: 16.793244ms
 ========== HyperNova<1,1> folding scheme ==========
-Prepare folding: 2.125681209s
-Transform input: 221.36µs
-Prove_step 0: 765.455805ms
-Prove_step 1: 848.616158ms
-Prove_step 2: 833.972256ms
-Prove_step 3: 864.703408ms
-Prove_step 4: 844.404617ms
-Prove_step 5: 865.9787ms
-Folding verification: 31.417487ms
+Prepare folding: 2.065175679s
+Transform input: 212.792µs
+Prove_step 0: 796.910579ms
+Prove_step 1: 853.848474ms
+Prove_step 2: 930.1784ms
+Prove_step 3: 872.190521ms
+Prove_step 4: 910.903061ms
+Prove_step 5: 939.589533ms
+Folding verification: 29.238423ms
 ========== HyperNova<2,2> folding scheme ==========
-Prepare folding: 2.843266713s
-Transform input: 3.922030432s
-Prove_step 0: 995.358483ms
-Prove_step 1: 1.209482586s
-thread 'main' panicked at src/folding.rs:159:6:
-Failed to verify folded proof: IVCVerificationFail
-note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
-make: *** [Makefile:17: run] Error 101
+Prepare folding: 2.995732852s
+Transform input: 3.9520013s
+Prove_step 0: 966.629701ms
+Prove_step 1: 1.22535041s
+Folding verification: 33.430805ms
 ```

src/folding.rs

@@ -31,6 +31,8 @@ pub struct StepInput<OtherInstances> {
 }
 
 pub trait FoldingSchemeExt: FoldingScheme<G1, G2, CircomFCircuit<Fr>> {
+    fn num_steps(num_inputs: usize) -> usize;
+
     fn prepreprocess(
         poseidon_config: PoseidonConfig<Fr>,
         circuit: CircomFCircuit<Fr>,
@@ -45,6 +47,11 @@ pub trait FoldingSchemeExt: FoldingScheme<G1, G2, CircomFCircuit<Fr>> {
 }
 
 impl FoldingSchemeExt for NovaFolding {
+    fn num_steps(num_inputs: usize) -> usize {
+        num_inputs // no multifolding
+    }
+
+
     fn prepreprocess(
         poseidon_config: PoseidonConfig<Fr>,
         circuit: CircomFCircuit<Fr>,
@@ -69,6 +76,12 @@ impl FoldingSchemeExt for NovaFolding {
 }
 
 impl<const N: usize, const M: usize> FoldingSchemeExt for HyperNovaFolding<N, M> {
+    fn num_steps(num_inputs: usize) -> usize {
+        let per_step = M + N - 1;
+        assert_eq!(num_inputs % per_step, 0);
+        num_inputs / per_step
+    }
+
     fn prepreprocess(
         poseidon_config: PoseidonConfig<Fr>,
         circuit: CircomFCircuit<Fr>,
@@ -144,14 +157,14 @@ pub fn verify_folding<FS: FoldingSchemeExt>(
     folding: &FS,
     folding_vp: FS::VerifierParam,
     start_ivc_state: Vec<Fr>,
-    num_steps: u32,
+    num_inputs: usize,
 ) {
     let (running_instance, incoming_instance, cyclefold_instance) = folding.instances();
     FS::verify(
         folding_vp,
         start_ivc_state,
         folding.state(),
-        Fr::from(num_steps),
+        Fr::from(FS::num_steps(num_inputs) as u32),
         running_instance,
         incoming_instance,
         cyclefold_instance,

src/main.rs

@@ -51,7 +51,7 @@ fn scenario<FS: FoldingSchemeExt>(config: ScenarioConfig, rng: &mut impl rand::R
             &folding,
             folding_vp,
             config.start_ivc_state,
-            config.num_steps as u32,
+            config.num_inputs,
         )
     });
 }

src/scenario_config.rs

@@ -6,7 +6,7 @@ use crate::{circuit::create_circuit, input::prepare_input, measure};
 
 #[derive(Clone)]
 pub struct ScenarioConfig {
-    pub num_steps: usize,
+    pub num_inputs: usize,
     pub start_ivc_state: Vec<Fr>,
     pub circuit: CircomFCircuit<Fr>,
     input: Vec<Vec<Fr>>,
@@ -15,7 +15,7 @@ pub struct ScenarioConfig {
 impl ScenarioConfig {
     pub fn new() -> Self {
         Self {
-            num_steps: 6,
+            num_inputs: 6,
             start_ivc_state: vec![Fr::zero(); 2],
             circuit: measure("Prepare circuit", create_circuit),
             input: measure("Prepare input", prepare_input),
@@ -23,6 +23,6 @@ impl ScenarioConfig {
     }
 
     pub fn input(&self) -> &[Vec<Fr>] {
-        &self.input[..self.num_steps]
+        &self.input[..self.num_inputs]
     }
 }