Full flow example (#90)

* expose params & structs for external usage

* add full_flow example, move examples into 'examples' dir

Author: arnaucube

.github/workflows/ci.yml

@@ -79,6 +79,10 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
+      - name: Download solc
+        run: |
+          curl -sSfL https://github.com/ethereum/solidity/releases/download/v0.8.4/solc-static-linux -o /usr/local/bin/solc
+          chmod +x /usr/local/bin/solc
       - name: Run examples tests
         run: cargo test --examples
       - name: Run examples

.gitignore

@@ -7,3 +7,6 @@ folding-schemes/src/frontend/circom/test_folder/cubic_circuit_js/
 
 # generated contracts at test time
 solidity-verifiers/generated
+examples/*.sol
+examples/*.calldata
+examples/*.inputs

…ding-schemes/examples/external_inputs.rs examples/external_inputs.rsfolding-schemes/examples/external_inputs.rs renamed to examples/external_inputs.rs folding-schemes/examples/external_inputs.rs renamed to examples/external_inputs.rs

@@ -0,0 +1,222 @@
+#![allow(non_snake_case)]
+#![allow(non_camel_case_types)]
+#![allow(clippy::upper_case_acronyms)]
+///
+/// This example performs the full flow:
+/// - define the circuit to be folded
+/// - fold the circuit with Nova+CycleFold's IVC
+/// - generate a DeciderEthCircuit final proof
+/// - generate the Solidity contract that verifies the proof
+/// - verify the proof in the EVM
+///
+use ark_bn254::{constraints::GVar, Bn254, Fr, G1Projective as G1};
+use ark_crypto_primitives::snark::SNARK;
+use ark_ff::PrimeField;
+use ark_groth16::VerifyingKey as G16VerifierKey;
+use ark_groth16::{Groth16, ProvingKey};
+use ark_grumpkin::{constraints::GVar as GVar2, Projective as G2};
+use ark_poly_commit::kzg10::VerifierKey as KZGVerifierKey;
+use ark_r1cs_std::alloc::AllocVar;
+use ark_r1cs_std::fields::fp::FpVar;
+use ark_relations::r1cs::{ConstraintSystemRef, SynthesisError};
+use ark_std::Zero;
+use std::marker::PhantomData;
+use std::time::Instant;
+
+use folding_schemes::{
+    commitment::{
+        kzg::{ProverKey as KZGProverKey, KZG},
+        pedersen::Pedersen,
+        CommitmentScheme,
+    },
+    folding::nova::{
+        decider_eth::{prepare_calldata, Decider as DeciderEth},
+        decider_eth_circuit::DeciderEthCircuit,
+        get_cs_params_len, Nova, ProverParams,
+    },
+    frontend::FCircuit,
+    transcript::poseidon::poseidon_test_config,
+    Decider, Error, FoldingScheme,
+};
+use solidity_verifiers::{
+    evm::{compile_solidity, Evm},
+    utils::get_function_selector_for_nova_cyclefold_verifier,
+    verifiers::nova_cyclefold::get_decider_template_for_cyclefold_decider,
+    NovaCycleFoldVerifierKey,
+};
+
+/// Test circuit to be folded
+#[derive(Clone, Copy, Debug)]
+pub struct CubicFCircuit<F: PrimeField> {
+    _f: PhantomData<F>,
+}
+impl<F: PrimeField> FCircuit<F> for CubicFCircuit<F> {
+    type Params = ();
+    fn new(_params: Self::Params) -> Self {
+        Self { _f: PhantomData }
+    }
+    fn state_len(&self) -> usize {
+        1
+    }
+    fn step_native(&self, _i: usize, z_i: Vec<F>) -> Result<Vec<F>, Error> {
+        Ok(vec![z_i[0] * z_i[0] * z_i[0] + z_i[0] + F::from(5_u32)])
+    }
+    fn generate_step_constraints(
+        &self,
+        cs: ConstraintSystemRef<F>,
+        _i: usize,
+        z_i: Vec<FpVar<F>>,
+    ) -> Result<Vec<FpVar<F>>, SynthesisError> {
+        let five = FpVar::<F>::new_constant(cs.clone(), F::from(5u32))?;
+        let z_i = z_i[0].clone();
+
+        Ok(vec![&z_i * &z_i * &z_i + &z_i + &five])
+    }
+}
+
+#[allow(clippy::type_complexity)]
+fn init_test_prover_params<FC: FCircuit<Fr, Params = ()>>() -> (
+    ProverParams<G1, G2, KZG<'static, Bn254>, Pedersen<G2>>,
+    KZGVerifierKey<Bn254>,
+) {
+    let mut rng = ark_std::test_rng();
+    let poseidon_config = poseidon_test_config::<Fr>();
+    let f_circuit = FC::new(());
+    let (cs_len, cf_cs_len) =
+        get_cs_params_len::<G1, GVar, G2, GVar2, FC>(&poseidon_config, f_circuit).unwrap();
+    let (kzg_pk, kzg_vk): (KZGProverKey<G1>, KZGVerifierKey<Bn254>) =
+        KZG::<Bn254>::setup(&mut rng, cs_len).unwrap();
+    let (cf_pedersen_params, _) = Pedersen::<G2>::setup(&mut rng, cf_cs_len).unwrap();
+    let fs_prover_params = ProverParams::<G1, G2, KZG<Bn254>, Pedersen<G2>> {
+        poseidon_config: poseidon_config.clone(),
+        cs_params: kzg_pk.clone(),
+        cf_cs_params: cf_pedersen_params,
+    };
+    (fs_prover_params, kzg_vk)
+}
+/// Initializes Nova parameters and DeciderEth parameters. Only for test purposes.
+#[allow(clippy::type_complexity)]
+fn init_params<FC: FCircuit<Fr, Params = ()>>() -> (
+    ProverParams<G1, G2, KZG<'static, Bn254>, Pedersen<G2>>,
+    KZGVerifierKey<Bn254>,
+    ProvingKey<Bn254>,
+    G16VerifierKey<Bn254>,
+) {
+    let mut rng = rand::rngs::OsRng;
+    let start = Instant::now();
+    let (fs_prover_params, kzg_vk) = init_test_prover_params::<FC>();
+    println!("generated Nova folding params: {:?}", start.elapsed());
+    let f_circuit = FC::new(());
+
+    pub type NOVA<FC> = Nova<G1, GVar, G2, GVar2, FC, KZG<'static, Bn254>, Pedersen<G2>>;
+    let z_0 = vec![Fr::zero(); f_circuit.state_len()];
+    let nova = NOVA::init(&fs_prover_params, f_circuit, z_0.clone()).unwrap();
+
+    let decider_circuit =
+        DeciderEthCircuit::<G1, GVar, G2, GVar2, KZG<Bn254>, Pedersen<G2>>::from_nova::<FC>(
+            nova.clone(),
+        )
+        .unwrap();
+    let start = Instant::now();
+    let (g16_pk, g16_vk) =
+        Groth16::<Bn254>::circuit_specific_setup(decider_circuit.clone(), &mut rng).unwrap();
+    println!(
+        "generated G16 (Decider circuit) params: {:?}",
+        start.elapsed()
+    );
+    (fs_prover_params, kzg_vk, g16_pk, g16_vk)
+}
+
+fn main() {
+    let n_steps = 10;
+    // set the initial state
+    let z_0 = vec![Fr::from(3_u32)];
+
+    let (fs_prover_params, kzg_vk, g16_pk, g16_vk) = init_params::<CubicFCircuit<Fr>>();
+
+    pub type NOVA = Nova<G1, GVar, G2, GVar2, CubicFCircuit<Fr>, KZG<'static, Bn254>, Pedersen<G2>>;
+    pub type DECIDERETH_FCircuit = DeciderEth<
+        G1,
+        GVar,
+        G2,
+        GVar2,
+        CubicFCircuit<Fr>,
+        KZG<'static, Bn254>,
+        Pedersen<G2>,
+        Groth16<Bn254>,
+        NOVA,
+    >;
+    let f_circuit = CubicFCircuit::<Fr>::new(());
+
+    // initialize the folding scheme engine, in our case we use Nova
+    let mut nova = NOVA::init(&fs_prover_params, f_circuit, z_0).unwrap();
+    // run n steps of the folding iteration
+    for i in 0..n_steps {
+        let start = Instant::now();
+        nova.prove_step().unwrap();
+        println!("Nova::prove_step {}: {:?}", i, start.elapsed());
+    }
+
+    let rng = rand::rngs::OsRng;
+    let start = Instant::now();
+    let proof = DECIDERETH_FCircuit::prove(
+        (g16_pk, fs_prover_params.cs_params.clone()),
+        rng,
+        nova.clone(),
+    )
+    .unwrap();
+    println!("generated Decider proof: {:?}", start.elapsed());
+
+    let verified = DECIDERETH_FCircuit::verify(
+        (g16_vk.clone(), kzg_vk.clone()),
+        nova.i,
+        nova.z_0.clone(),
+        nova.z_i.clone(),
+        &nova.U_i,
+        &nova.u_i,
+        &proof,
+    )
+    .unwrap();
+    assert!(verified);
+    println!("Decider proof verification: {}", verified);
+
+    // Now, let's generate the Solidity code that verifies this Decider final proof
+    let function_selector =
+        get_function_selector_for_nova_cyclefold_verifier(nova.z_0.len() * 2 + 1);
+
+    let calldata: Vec<u8> = prepare_calldata(
+        function_selector,
+        nova.i,
+        nova.z_0,
+        nova.z_i,
+        &nova.U_i,
+        &nova.u_i,
+        proof,
+    )
+    .unwrap();
+
+    // prepare the setup params for the solidity verifier
+    let nova_cyclefold_vk = NovaCycleFoldVerifierKey::from((g16_vk, kzg_vk, f_circuit.state_len()));
+
+    // generate the solidity code
+    let decider_solidity_code = get_decider_template_for_cyclefold_decider(nova_cyclefold_vk);
+
+    // verify the proof against the solidity code in the EVM
+    let nova_cyclefold_verifier_bytecode = compile_solidity(&decider_solidity_code, "NovaDecider");
+    let mut evm = Evm::default();
+    let verifier_address = evm.create(nova_cyclefold_verifier_bytecode);
+    let (_, output) = evm.call(verifier_address, calldata.clone());
+    assert_eq!(*output.last().unwrap(), 1);
+
+    // save smart contract and the calldata
+    println!("storing nova-verifier.sol and the calldata into files");
+    use std::fs;
+    fs::write(
+        "./examples/nova-verifier.sol",
+        decider_solidity_code.clone(),
+    )
+    .unwrap();
+    fs::write("./examples/solidity-calldata.calldata", calldata.clone()).unwrap();
+    let s = solidity_verifiers::utils::get_formatted_calldata(calldata.clone());
+    fs::write("./examples/solidity-calldata.inputs", s.join(",\n")).expect("");
+}

examples/full_flow.rs

@@ -11,7 +11,7 @@ use folding_schemes::folding::nova::{get_r1cs, ProverParams, VerifierParams};
 use folding_schemes::frontend::FCircuit;
 use folding_schemes::transcript::poseidon::poseidon_test_config;
 
-// This method computes the Prover & Verifier parameters for the example.
+// This method computes the Nova's Prover & Verifier parameters for the example.
 // Warning: this method is only for testing purposes. For a real world use case those parameters
 // should be generated carefully (both the PoseidonConfig and the PedersenParams).
 #[allow(clippy::type_complexity)]

folding-schemes/examples/multi_inputs.rs examples/multi_inputs.rsfolding-schemes/examples/multi_inputs.rs renamed to examples/multi_inputs.rs

@@ -47,3 +47,16 @@ parallel = [
     "ark-crypto-primitives/parallel",  
     "ark-r1cs-std/parallel",  
     ]
+
+
+[[example]]
+name = "sha256"
+path = "../examples/sha256.rs"
+
+[[example]]
+name = "multi_inputs"
+path = "../examples/multi_inputs.rs"
+
+[[example]]
+name = "external_inputs"
+path = "../examples/external_inputs.rs"

folding-schemes/examples/sha256.rs examples/sha256.rsfolding-schemes/examples/sha256.rs renamed to examples/sha256.rs

@@ -83,7 +83,7 @@ impl<F: PrimeField> FCircuit<F> for CircomFCircuit<F> {
         let circom_circuit = CircomCircuit {
             r1cs,
             witness: witness.clone(),
-            inputs_already_computed: true,
+            inputs_already_allocated: true,
         };
 
         // Generates the constraints for the circom_circuit.

folding-schemes/examples/utils.rs examples/utils.rsfolding-schemes/examples/utils.rs renamed to examples/utils.rs

@@ -140,7 +140,7 @@ mod tests {
         let circom_circuit = CircomCircuit {
             r1cs,
             witness,
-            inputs_already_computed: false,
+            inputs_already_allocated: false,
         };
 
         circom_circuit.generate_constraints(cs.clone()).unwrap();