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implement HyperNova's DeciderEth circuit (#132)

The HyperNova's DeciderEthCircuit follows a similar logic as Nova's one
described in
https://privacy-scaling-explorations.github.io/sonobe-docs/design/nova-decider-onchain.html
but adapted to HyperNova checks and values.
update-nifs-interface
arnaucube 3 months ago
committed by GitHub
parent
commit
f6a70fe1d0
No known key found for this signature in database GPG Key ID: B5690EEEBB952194
8 changed files with 719 additions and 38 deletions
  1. +1
    -0
      folding-schemes/Cargo.toml
  2. +35
    -0
      folding-schemes/src/folding/circuits/cyclefold.rs
  3. +1
    -1
      folding-schemes/src/folding/circuits/nonnative/affine.rs
  4. +639
    -0
      folding-schemes/src/folding/hypernova/decider_eth_circuit.rs
  5. +1
    -0
      folding-schemes/src/folding/hypernova/mod.rs
  6. +6
    -36
      folding-schemes/src/folding/nova/decider_eth_circuit.rs
  7. +4
    -1
      folding-schemes/src/folding/nova/mod.rs
  8. +32
    -0
      folding-schemes/src/utils/gadgets.rs

+ 1
- 0
folding-schemes/Cargo.toml

@ -30,6 +30,7 @@ serde_json = "1.0.85"
serde = "1.0.203"
acvm = { git = "https://github.com/noir-lang/noir", rev="2b4853e", default-features = false }
arkworks_backend = { git = "https://github.com/dmpierre/arkworks_backend", branch="feat/sonobe-integration" }
log = "0.4"
# tmp import for espresso's sumcheck
espresso_subroutines = {git="https://github.com/EspressoSystems/hyperplonk", package="subroutines"}

+ 35
- 0
folding-schemes/src/folding/circuits/cyclefold.rs

@ -215,6 +215,41 @@ where
}
}
/// In-circuit representation of the Witness associated to the CommittedInstance, but with
/// non-native representation, since it is used to represent the CycleFold witness. This struct is
/// used in the Decider circuit.
#[derive(Debug, Clone)]
pub struct CycleFoldWitnessVar<C: CurveGroup> {
pub E: Vec<NonNativeUintVar<CF2<C>>>,
pub rE: NonNativeUintVar<CF2<C>>,
pub W: Vec<NonNativeUintVar<CF2<C>>>,
pub rW: NonNativeUintVar<CF2<C>>,
}
impl<C> AllocVar<CycleFoldWitness<C>, CF2<C>> for CycleFoldWitnessVar<C>
where
C: CurveGroup,
<C as ark_ec::CurveGroup>::BaseField: PrimeField,
{
fn new_variable<T: Borrow<CycleFoldWitness<C>>>(
cs: impl Into<Namespace<CF2<C>>>,
f: impl FnOnce() -> Result<T, SynthesisError>,
mode: AllocationMode,
) -> Result<Self, SynthesisError> {
f().and_then(|val| {
let cs = cs.into();
let E = Vec::new_variable(cs.clone(), || Ok(val.borrow().E.clone()), mode)?;
let rE = NonNativeUintVar::new_variable(cs.clone(), || Ok(val.borrow().rE), mode)?;
let W = Vec::new_variable(cs.clone(), || Ok(val.borrow().W.clone()), mode)?;
let rW = NonNativeUintVar::new_variable(cs.clone(), || Ok(val.borrow().rW), mode)?;
Ok(Self { E, rE, W, rW })
})
}
}
/// This is the gadget used in the AugmentedFCircuit to verify the CycleFold instances folding,
/// which checks the correct RLC of u,x,cmE,cmW (hence the name containing 'Full', since it checks
/// all the RLC values, not only the native ones). It assumes that ci2.cmE=0, ci2.u=1.

+ 1
- 1
folding-schemes/src/folding/circuits/nonnative/affine.rs

@ -57,7 +57,7 @@ impl ToConstraintFieldGadget for NonNativeAffineV
/// The out-circuit counterpart of `NonNativeAffineVar::to_constraint_field`
#[allow(clippy::type_complexity)]
fn nonnative_affine_to_field_elements<C: CurveGroup>(
pub(crate) fn nonnative_affine_to_field_elements<C: CurveGroup>(
p: C,
) -> (Vec<C::ScalarField>, Vec<C::ScalarField>) {
let affine = p.into_affine();

+ 639
- 0
folding-schemes/src/folding/hypernova/decider_eth_circuit.rs

@ -0,0 +1,639 @@
/// This file implements the onchain (Ethereum's EVM) decider circuit. For non-ethereum use cases,
/// other more efficient approaches can be used.
use ark_crypto_primitives::sponge::{
constraints::CryptographicSpongeVar,
poseidon::{constraints::PoseidonSpongeVar, PoseidonConfig, PoseidonSponge},
Absorb, CryptographicSponge,
};
use ark_ec::{CurveGroup, Group};
use ark_ff::PrimeField;
use ark_poly::Polynomial;
use ark_r1cs_std::{
alloc::{AllocVar, AllocationMode},
boolean::Boolean,
eq::EqGadget,
fields::fp::FpVar,
groups::GroupOpsBounds,
prelude::CurveVar,
ToConstraintFieldGadget,
};
use ark_relations::r1cs::{ConstraintSynthesizer, ConstraintSystemRef, Namespace, SynthesisError};
use ark_std::Zero;
use core::{borrow::Borrow, marker::PhantomData};
use super::{
circuits::{CCCSVar, LCCCSVar, NIMFSGadget, ProofVar as NIMFSProofVar},
nimfs::{NIMFSProof, NIMFS},
HyperNova, Witness, CCCS, LCCCS,
};
use crate::arith::ccs::CCS;
use crate::arith::r1cs::R1CS;
use crate::commitment::{pedersen::Params as PedersenParams, CommitmentScheme};
use crate::folding::circuits::{
cyclefold::{CycleFoldCommittedInstance, CycleFoldWitness},
CF1, CF2,
};
use crate::frontend::FCircuit;
use crate::transcript::{Transcript, TranscriptVar};
use crate::utils::{
gadgets::{eval_mle, MatrixGadget, SparseMatrixVar},
vec::poly_from_vec,
};
use crate::Error;
/// In-circuit representation of the Witness associated to the CommittedInstance.
#[derive(Debug, Clone)]
pub struct WitnessVar<F: PrimeField> {
pub w: Vec<FpVar<F>>,
pub r_w: FpVar<F>,
}
impl<F: PrimeField> AllocVar<Witness<F>, F> for WitnessVar<F> {
fn new_variable<T: Borrow<Witness<F>>>(
cs: impl Into<Namespace<F>>,
f: impl FnOnce() -> Result<T, SynthesisError>,
mode: AllocationMode,
) -> Result<Self, SynthesisError> {
f().and_then(|val| {
let cs = cs.into();
let w: Vec<FpVar<F>> =
Vec::new_variable(cs.clone(), || Ok(val.borrow().w.clone()), mode)?;
let r_w = FpVar::<F>::new_variable(cs.clone(), || Ok(val.borrow().r_w), mode)?;
Ok(Self { w, r_w })
})
}
}
/// CCSMatricesVar contains the matrices 'M' of the CCS without the rest of CCS parameters.
#[derive(Debug, Clone)]
pub struct CCSMatricesVar<F: PrimeField> {
// we only need native representation, so the constraint field==F
pub M: Vec<SparseMatrixVar<F, F, FpVar<F>>>,
}
impl<F> AllocVar<CCS<F>, F> for CCSMatricesVar<F>
where
F: PrimeField,
{
fn new_variable<T: Borrow<CCS<F>>>(
cs: impl Into<Namespace<F>>,
f: impl FnOnce() -> Result<T, SynthesisError>,
_mode: AllocationMode,
) -> Result<Self, SynthesisError> {
f().and_then(|val| {
let cs = cs.into();
let M: Vec<SparseMatrixVar<F, F, FpVar<F>>> = val
.borrow()
.M
.iter()
.map(|M| SparseMatrixVar::<F, F, FpVar<F>>::new_constant(cs.clone(), M.clone()))
.collect::<Result<_, SynthesisError>>()?;
Ok(Self { M })
})
}
}
/// Gadget to check the LCCCS relation both over the native constraint field and over the
/// non-native constraint field.
#[derive(Debug, Clone)]
pub struct LCCCSCheckerGadget {}
impl LCCCSCheckerGadget {
/// performs in-circuit the RelaxedR1CS check for native variables (Az∘Bz==uCz+E)
pub fn check<F: PrimeField>(
s: usize,
ccs_mat: CCSMatricesVar<F>,
z: Vec<FpVar<F>>,
// LCCCS values
r_x: Vec<FpVar<F>>,
v: Vec<FpVar<F>>,
) -> Result<(), SynthesisError> {
let computed_v: Vec<FpVar<F>> = ccs_mat
.M
.iter()
.map(|M_j| {
let Mz = M_j.mul_vector(&z)?;
Ok(eval_mle(s, Mz, r_x.clone()))
})
.collect::<Result<Vec<FpVar<F>>, SynthesisError>>()?;
(computed_v).enforce_equal(&v)?;
Ok(())
}
}
/// Circuit that implements the in-circuit checks needed for the HyperNova's onchain (Ethereum's
/// EVM) verification.
#[derive(Clone, Debug)]
pub struct DeciderEthCircuit<C1, GC1, C2, GC2, CS1, CS2, const H: bool = false>
where
C1: CurveGroup,
GC1: CurveVar<C1, CF2<C1>>,
C2: CurveGroup,
GC2: CurveVar<C2, CF2<C2>>,
CS1: CommitmentScheme<C1, H>,
CS2: CommitmentScheme<C2, H>,
{
_c1: PhantomData<C1>,
_gc1: PhantomData<GC1>,
_c2: PhantomData<C2>,
_gc2: PhantomData<GC2>,
_cs1: PhantomData<CS1>,
_cs2: PhantomData<CS2>,
/// E vector's length of the CycleFold instance witness
pub cf_E_len: usize,
/// CCS of the Augmented Function circuit
pub ccs: CCS<C1::ScalarField>,
/// R1CS of the CycleFold circuit
pub cf_r1cs: R1CS<C2::ScalarField>,
/// CycleFold PedersenParams over C2
pub cf_pedersen_params: PedersenParams<C2>,
pub poseidon_config: PoseidonConfig<CF1<C1>>,
/// public params hash
pub pp_hash: Option<C1::ScalarField>,
pub i: Option<CF1<C1>>,
/// initial state
pub z_0: Option<Vec<C1::ScalarField>>,
/// current i-th state
pub z_i: Option<Vec<C1::ScalarField>>,
/// Nova instances
pub U_i: Option<LCCCS<C1>>,
pub W_i: Option<Witness<C1::ScalarField>>,
pub u_i: Option<CCCS<C1>>,
pub w_i: Option<Witness<C1::ScalarField>>,
pub U_i1: Option<LCCCS<C1>>,
pub W_i1: Option<Witness<C1::ScalarField>>,
pub nimfs_proof: Option<NIMFSProof<C1>>,
// rho_0 is the first and only rho in the 'rho_powers' array, since it comes from NIMFS-folding
// only 2 instances.
pub rho_0: Option<C1::ScalarField>,
/// CycleFold running instance
pub cf_U_i: Option<CycleFoldCommittedInstance<C2>>,
pub cf_W_i: Option<CycleFoldWitness<C2>>,
/// KZG challenge & eval
pub kzg_challenge: Option<C1::ScalarField>,
pub eval_W: Option<C1::ScalarField>,
}
impl<C1, GC1, C2, GC2, CS1, CS2, const H: bool> DeciderEthCircuit<C1, GC1, C2, GC2, CS1, CS2, H>
where
C1: CurveGroup,
C2: CurveGroup,
GC1: CurveVar<C1, CF2<C1>> + ToConstraintFieldGadget<CF2<C1>>,
GC2: CurveVar<C2, CF2<C2>> + ToConstraintFieldGadget<CF2<C2>>,
CS1: CommitmentScheme<C1, H>,
// enforce that the CS2 is Pedersen commitment scheme, since we're at Ethereum's EVM decider
CS2: CommitmentScheme<C2, H, ProverParams = PedersenParams<C2>>,
<C1 as Group>::ScalarField: Absorb,
<C1 as CurveGroup>::BaseField: PrimeField,
{
/// returns an instance of the DeciderEthCircuit from the given HyperNova struct
pub fn from_hypernova<FC: FCircuit<C1::ScalarField>, const MU: usize, const NU: usize>(
hn: HyperNova<C1, GC1, C2, GC2, FC, CS1, CS2, MU, NU, H>,
) -> Result<Self, Error> {
// compute the U_{i+1}, W_{i+1}, by folding the last running & incoming instances
let mut transcript = PoseidonSponge::<C1::ScalarField>::new(&hn.poseidon_config);
transcript.absorb(&hn.pp_hash);
let (nimfs_proof, U_i1, W_i1, rho_powers) =
NIMFS::<C1, PoseidonSponge<C1::ScalarField>>::prove(
&mut transcript,
&hn.ccs,
&[hn.U_i.clone()],
&[hn.u_i.clone()],
&[hn.W_i.clone()],
&[hn.w_i.clone()],
)?;
// compute the KZG challenges used as inputs in the circuit
let kzg_challenge =
KZGChallengeGadget::<C1>::get_challenge_native(&mut transcript, U_i1.clone())?;
// get KZG evals
let mut W = W_i1.w.clone();
W.extend(
std::iter::repeat(C1::ScalarField::zero())
.take(W_i1.w.len().next_power_of_two() - W_i1.w.len()),
);
let p_W = poly_from_vec(W.to_vec())?;
let eval_W = p_W.evaluate(&kzg_challenge);
// ensure that we only have 1 element in rho_powers, since we only NIMFS-fold 2 instances
if rho_powers.len() != 1 {
return Err(Error::NotExpectedLength(rho_powers.len(), 1));
}
Ok(Self {
_c1: PhantomData,
_gc1: PhantomData,
_c2: PhantomData,
_gc2: PhantomData,
_cs1: PhantomData,
_cs2: PhantomData,
cf_E_len: hn.cf_W_i.E.len(),
ccs: hn.ccs,
cf_r1cs: hn.cf_r1cs,
cf_pedersen_params: hn.cf_cs_params,
poseidon_config: hn.poseidon_config,
pp_hash: Some(hn.pp_hash),
i: Some(hn.i),
z_0: Some(hn.z_0),
z_i: Some(hn.z_i),
U_i: Some(hn.U_i),
W_i: Some(hn.W_i),
u_i: Some(hn.u_i),
w_i: Some(hn.w_i),
U_i1: Some(U_i1),
W_i1: Some(W_i1),
nimfs_proof: Some(nimfs_proof),
rho_0: Some(rho_powers[0]),
cf_U_i: Some(hn.cf_U_i),
cf_W_i: Some(hn.cf_W_i),
kzg_challenge: Some(kzg_challenge),
eval_W: Some(eval_W),
})
}
}
impl<C1, GC1, C2, GC2, CS1, CS2> ConstraintSynthesizer<CF1<C1>>
for DeciderEthCircuit<C1, GC1, C2, GC2, CS1, CS2>
where
C1: CurveGroup,
C2: CurveGroup,
GC1: CurveVar<C1, CF2<C1>>,
GC2: CurveVar<C2, CF2<C2>> + ToConstraintFieldGadget<CF2<C2>>,
CS1: CommitmentScheme<C1>,
CS2: CommitmentScheme<C2>,
C1::ScalarField: PrimeField,
<C1 as CurveGroup>::BaseField: PrimeField,
<C2 as CurveGroup>::BaseField: PrimeField,
<C1 as Group>::ScalarField: Absorb,
<C2 as Group>::ScalarField: Absorb,
C1: CurveGroup<BaseField = C2::ScalarField, ScalarField = C2::BaseField>,
for<'b> &'b GC2: GroupOpsBounds<'b, C2, GC2>,
{
fn generate_constraints(self, cs: ConstraintSystemRef<CF1<C1>>) -> Result<(), SynthesisError> {
let ccs_matrices =
CCSMatricesVar::<C1::ScalarField>::new_witness(cs.clone(), || Ok(self.ccs.clone()))?;
let pp_hash = FpVar::<CF1<C1>>::new_input(cs.clone(), || {
Ok(self.pp_hash.unwrap_or_else(CF1::<C1>::zero))
})?;
let i =
FpVar::<CF1<C1>>::new_input(cs.clone(), || Ok(self.i.unwrap_or_else(CF1::<C1>::zero)))?;
let z_0 = Vec::<FpVar<CF1<C1>>>::new_input(cs.clone(), || {
Ok(self.z_0.unwrap_or(vec![CF1::<C1>::zero()]))
})?;
let z_i = Vec::<FpVar<CF1<C1>>>::new_input(cs.clone(), || {
Ok(self.z_i.unwrap_or(vec![CF1::<C1>::zero()]))
})?;
let U_dummy_native = LCCCS::<C1>::dummy(self.ccs.l, self.ccs.t, self.ccs.s);
let u_dummy_native = CCCS::<C1>::dummy(self.ccs.l);
let w_dummy_native = Witness::<C1::ScalarField>::new(
vec![C1::ScalarField::zero(); self.ccs.n - 3 /* (3=2+1, since u_i.x.len=2) */],
);
let U_i = LCCCSVar::<C1>::new_witness(cs.clone(), || {
Ok(self.U_i.unwrap_or(U_dummy_native.clone()))
})?;
let u_i = CCCSVar::<C1>::new_witness(cs.clone(), || {
Ok(self.u_i.unwrap_or(u_dummy_native.clone()))
})?;
// here (U_i1, W_i1) = NIFS.P( (U_i,W_i), (u_i,w_i))
let U_i1 = LCCCSVar::<C1>::new_input(cs.clone(), || {
Ok(self.U_i1.unwrap_or(U_dummy_native.clone()))
})?;
let W_i1 = WitnessVar::<C1::ScalarField>::new_witness(cs.clone(), || {
Ok(self.W_i1.unwrap_or(w_dummy_native.clone()))
})?;
let nimfs_proof_dummy = NIMFSProof::<C1>::dummy(&self.ccs, 1, 1); // mu=1 & nu=1 because the last fold is 2-to-1
let nimfs_proof = NIMFSProofVar::<C1>::new_witness(cs.clone(), || {
Ok(self.nimfs_proof.unwrap_or(nimfs_proof_dummy))
})?;
// allocate the inputs for the check 6
let kzg_challenge = FpVar::<CF1<C1>>::new_input(cs.clone(), || {
Ok(self.kzg_challenge.unwrap_or_else(CF1::<C1>::zero))
})?;
let _eval_W = FpVar::<CF1<C1>>::new_input(cs.clone(), || {
Ok(self.eval_W.unwrap_or_else(CF1::<C1>::zero))
})?;
// `sponge` is for digest computation.
let sponge = PoseidonSpongeVar::<C1::ScalarField>::new(cs.clone(), &self.poseidon_config);
// `transcript` is for challenge generation.
let mut transcript = sponge.clone();
transcript.absorb(&pp_hash)?;
// NOTE: we use the same enumeration as in Nova's DeciderEthCircuit described at
// https://privacy-scaling-explorations.github.io/sonobe-docs/design/nova-decider-onchain.html
// in order to make it easier to reason about.
// 1. check LCCCS relation of U_{i+1}
let z_U1: Vec<FpVar<CF1<C1>>> =
[vec![U_i1.u.clone()], U_i1.x.to_vec(), W_i1.w.to_vec()].concat();
LCCCSCheckerGadget::check(
self.ccs.s,
ccs_matrices,
z_U1,
U_i1.r_x.clone(),
U_i1.v.clone(),
)?;
// 3.a u_i.x[0] == H(i, z_0, z_i, U_i)
let (u_i_x, _) = U_i.clone().hash(
&sponge,
pp_hash.clone(),
i.clone(),
z_0.clone(),
z_i.clone(),
)?;
(u_i.x[0]).enforce_equal(&u_i_x)?;
#[cfg(feature = "light-test")]
log::warn!("[WARNING]: Running with the 'light-test' feature, skipping the big part of the DeciderEthCircuit.\n Only for testing purposes.");
// The following two checks (and their respective allocations) are disabled for normal
// tests since they take several millions of constraints and would take several minutes
// (and RAM) to run the test. It is active by default, and not active only when
// 'light-test' feature is used.
#[cfg(not(feature = "light-test"))]
{
// imports here instead of at the top of the file, so we avoid having multiple
// `#[cfg(not(test))]`
use crate::commitment::pedersen::PedersenGadget;
use crate::folding::circuits::nonnative::uint::NonNativeUintVar;
use crate::folding::nova::decider_eth_circuit::{R1CSVar, RelaxedR1CSGadget};
use crate::folding::{
circuits::cyclefold::{
CycleFoldCommittedInstanceVar, CycleFoldConfig, CycleFoldWitnessVar,
},
nova::NovaCycleFoldConfig,
};
use ark_r1cs_std::ToBitsGadget;
let cf_u_dummy_native =
CycleFoldCommittedInstance::<C2>::dummy(NovaCycleFoldConfig::<C1>::IO_LEN);
let cf_w_dummy_native = CycleFoldWitness::<C2>::dummy(
self.cf_r1cs.A.n_cols - 1 - self.cf_r1cs.l,
self.cf_E_len,
);
let cf_U_i = CycleFoldCommittedInstanceVar::<C2, GC2>::new_witness(cs.clone(), || {
Ok(self.cf_U_i.unwrap_or_else(|| cf_u_dummy_native.clone()))
})?;
let cf_W_i = CycleFoldWitnessVar::<C2>::new_witness(cs.clone(), || {
Ok(self.cf_W_i.unwrap_or(cf_w_dummy_native.clone()))
})?;
// 3.b u_i.x[1] == H(cf_U_i)
let (cf_u_i_x, _) = cf_U_i.clone().hash(&sponge, pp_hash.clone())?;
(u_i.x[1]).enforce_equal(&cf_u_i_x)?;
// 4. check Pedersen commitments of cf_U_i.{cmE, cmW}
let H = GC2::new_constant(cs.clone(), self.cf_pedersen_params.h)?;
let G = Vec::<GC2>::new_constant(cs.clone(), self.cf_pedersen_params.generators)?;
let cf_W_i_E_bits: Result<Vec<Vec<Boolean<CF1<C1>>>>, SynthesisError> =
cf_W_i.E.iter().map(|E_i| E_i.to_bits_le()).collect();
let cf_W_i_W_bits: Result<Vec<Vec<Boolean<CF1<C1>>>>, SynthesisError> =
cf_W_i.W.iter().map(|W_i| W_i.to_bits_le()).collect();
let computed_cmE = PedersenGadget::<C2, GC2>::commit(
H.clone(),
G.clone(),
cf_W_i_E_bits?,
cf_W_i.rE.to_bits_le()?,
)?;
cf_U_i.cmE.enforce_equal(&computed_cmE)?;
let computed_cmW =
PedersenGadget::<C2, GC2>::commit(H, G, cf_W_i_W_bits?, cf_W_i.rW.to_bits_le()?)?;
cf_U_i.cmW.enforce_equal(&computed_cmW)?;
let cf_r1cs =
R1CSVar::<C1::BaseField, CF1<C1>, NonNativeUintVar<CF1<C1>>>::new_witness(
cs.clone(),
|| Ok(self.cf_r1cs.clone()),
)?;
// 5. check RelaxedR1CS of cf_U_i
let cf_z_U = [vec![cf_U_i.u.clone()], cf_U_i.x.to_vec(), cf_W_i.W.to_vec()].concat();
RelaxedR1CSGadget::check_nonnative(cf_r1cs, cf_W_i.E, cf_U_i.u.clone(), cf_z_U)?;
}
// The following steps are in non-increasing order because the `computed_U_i1` is computed
// at step 8, and later used at step 6. Notice that in Nova, we compute U_i1 outside of the
// circuit, in the smart contract, but here we're computing it in-circuit, and we reuse the
// `rho_vec` computed along the way of computing `computed_U_i1` for the later `rho_powers`
// check (6.b).
// Check 7 is temporary disabled due
// https://github.com/privacy-scaling-explorations/sonobe/issues/80
log::warn!("[WARNING]: issue #80 (https://github.com/privacy-scaling-explorations/sonobe/issues/80) is not resolved yet.");
//
// 7. check eval_W==p_W(c_W)
// let incircuit_eval_W = evaluate_gadget::<CF1<C1>>(W_i1.W, incircuit_c_W)?;
// incircuit_eval_W.enforce_equal(&eval_W)?;
// 8.a verify the NIMFS.V of the final fold, and check that the obtained rho_powers from the
// transcript match the one from the public input (so we avoid the onchain logic of the
// verifier computing it).
// Notice that the NIMFSGadget performs all the logic except of checking the fold of the
// instances C parameter, which would require non-native arithmetic, henceforth we perform
// that check outside the circuit.
let (computed_U_i1, rho_vec) = NIMFSGadget::<C1>::verify(
cs.clone(),
&self.ccs.clone(),
&mut transcript,
&[U_i],
&[u_i],
nimfs_proof,
Boolean::TRUE, // enabled
)?;
// 6.a check KZG challenges
// Notice that this step is done after the NIMFS.V, to follow the transcript absorbs order
// done outside the circuit, where to compute the challenge it needs first to compute the
// U_{i+1} through the NIMFS.V
let incircuit_challenge =
KZGChallengeGadget::<C1>::get_challenge_gadget(&mut transcript, U_i1.clone())?;
incircuit_challenge.enforce_equal(&kzg_challenge)?;
// 6.b check that the obtained U_{i+1} from the NIMFS.V matches the U_{i+1} from the input,
// except for the C parameter, which to compute its folding would require non-native logic
// in-circuit, and we defer it to outside the circuit.
computed_U_i1.u.enforce_equal(&U_i1.u)?;
computed_U_i1.r_x.enforce_equal(&U_i1.r_x)?;
computed_U_i1.v.enforce_equal(&U_i1.v)?;
// 8.b check that the in-circuit computed r is equal to the inputted r.
// Notice that rho_vec only contains one element, since at the final fold we are only
// folding 2-to-1 instances.
// Ensure that rho_vec is of length 1, note that this is not enforced at the constraint
// level but more as a check for the prover.
if rho_vec.len() != 1 {
return Err(SynthesisError::Unsatisfiable);
}
let rho_0 = Boolean::le_bits_to_fp_var(&rho_vec[0])?;
let external_rho_0 = FpVar::<CF1<C1>>::new_input(cs.clone(), || {
Ok(self.rho_0.unwrap_or(CF1::<C1>::zero()))
})?;
rho_0.enforce_equal(&external_rho_0)?;
Ok(())
}
}
/// Gadget that computes the KZG challenges, also offers the rust native implementation compatible
/// with the gadget.
pub struct KZGChallengeGadget<C: CurveGroup> {
_c: PhantomData<C>,
}
#[allow(clippy::type_complexity)]
impl<C> KZGChallengeGadget<C>
where
C: CurveGroup,
C::ScalarField: PrimeField,
<C as CurveGroup>::BaseField: PrimeField,
C::ScalarField: Absorb,
{
pub fn get_challenge_native<T: Transcript<C::ScalarField>>(
transcript: &mut T,
U_i: LCCCS<C>,
) -> Result<C::ScalarField, Error> {
// compute the KZG challenges, which are computed in-circuit and checked that it matches
// the inputted one
transcript.absorb_nonnative(&U_i.C);
Ok(transcript.get_challenge())
}
// compatible with the native get_challenge_native
pub fn get_challenge_gadget<S: CryptographicSponge, T: TranscriptVar<CF1<C>, S>>(
transcript: &mut T,
U_i: LCCCSVar<C>,
) -> Result<FpVar<C::ScalarField>, SynthesisError> {
transcript.absorb(&U_i.C.to_constraint_field()?)?;
transcript.get_challenge()
}
}
#[cfg(test)]
pub mod tests {
use ark_bn254::{constraints::GVar, Fr, G1Projective as Projective};
use ark_grumpkin::{constraints::GVar as GVar2, Projective as Projective2};
use ark_relations::r1cs::ConstraintSystem;
use ark_std::One;
use ark_std::{test_rng, UniformRand};
use super::*;
use crate::commitment::pedersen::Pedersen;
use crate::folding::nova::PreprocessorParam;
use crate::frontend::tests::CubicFCircuit;
use crate::transcript::poseidon::poseidon_canonical_config;
use crate::FoldingScheme;
#[test]
fn test_lcccs_checker_gadget() {
let mut rng = test_rng();
let n_rows = 2_u32.pow(5) as usize;
let n_cols = 2_u32.pow(5) as usize;
let r1cs = R1CS::<Fr>::rand(&mut rng, n_rows, n_cols);
let ccs = CCS::from_r1cs(r1cs);
let z: Vec<Fr> = (0..n_cols).map(|_| Fr::rand(&mut rng)).collect();
let (pedersen_params, _) =
Pedersen::<Projective>::setup(&mut rng, ccs.n - ccs.l - 1).unwrap();
let (lcccs, _) = ccs
.to_lcccs::<_, Projective, Pedersen<Projective>, false>(&mut rng, &pedersen_params, &z)
.unwrap();
let cs = ConstraintSystem::<Fr>::new_ref();
// CCS's (sparse) matrices are constants in the circuit
let ccs_mat = CCSMatricesVar::<Fr>::new_constant(cs.clone(), ccs.clone()).unwrap();
let zVar = Vec::<FpVar<Fr>>::new_input(cs.clone(), || Ok(z)).unwrap();
let r_xVar = Vec::<FpVar<Fr>>::new_input(cs.clone(), || Ok(lcccs.r_x)).unwrap();
let vVar = Vec::<FpVar<Fr>>::new_input(cs.clone(), || Ok(lcccs.v)).unwrap();
LCCCSCheckerGadget::check(ccs.s, ccs_mat, zVar, r_xVar, vVar).unwrap();
assert!(cs.is_satisfied().unwrap());
}
#[test]
fn test_decider_circuit() {
let mut rng = ark_std::test_rng();
let poseidon_config = poseidon_canonical_config::<Fr>();
let F_circuit = CubicFCircuit::<Fr>::new(()).unwrap();
let z_0 = vec![Fr::from(3_u32)];
const MU: usize = 1;
const NU: usize = 1;
type HN = HyperNova<
Projective,
GVar,
Projective2,
GVar2,
CubicFCircuit<Fr>,
Pedersen<Projective>,
Pedersen<Projective2>,
MU,
NU,
false,
>;
let prep_param = PreprocessorParam::<
Projective,
Projective2,
CubicFCircuit<Fr>,
Pedersen<Projective>,
Pedersen<Projective2>,
false,
>::new(poseidon_config, F_circuit);
let hn_params = HN::preprocess(&mut rng, &prep_param).unwrap();
// generate a Nova instance and do a step of it
let mut hypernova = HN::init(&hn_params, F_circuit, z_0.clone()).unwrap();
hypernova
.prove_step(&mut rng, vec![], Some((vec![], vec![])))
.unwrap();
let ivc_v = hypernova.clone();
let (running_instance, incoming_instance, cyclefold_instance) = ivc_v.instances();
HN::verify(
hn_params.1, // HN's verifier_params
z_0,
ivc_v.z_i,
Fr::one(),
running_instance,
incoming_instance,
cyclefold_instance,
)
.unwrap();
// load the DeciderEthCircuit from the generated Nova instance
let decider_circuit = DeciderEthCircuit::<
Projective,
GVar,
Projective2,
GVar2,
Pedersen<Projective>,
Pedersen<Projective2>,
>::from_hypernova(hypernova)
.unwrap();
let cs = ConstraintSystem::<Fr>::new_ref();
// generate the constraints and check that are satisfied by the inputs
decider_circuit.generate_constraints(cs.clone()).unwrap();
assert!(cs.is_satisfied().unwrap());
dbg!(cs.num_constraints());
}
}

+ 1
- 0
folding-schemes/src/folding/hypernova/mod.rs

@ -10,6 +10,7 @@ use ark_std::{fmt::Debug, marker::PhantomData, rand::RngCore, One, Zero};
pub mod cccs;
pub mod circuits;
pub mod decider_eth_circuit;
pub mod lcccs;
pub mod nimfs;
pub mod utils;

+ 6
- 36
folding-schemes/src/folding/nova/decider_eth_circuit.rs

@ -160,40 +160,6 @@ where
}
}
/// In-circuit representation of the Witness associated to the CycleFoldCommittedInstance, but with
/// non-native representation, since it is used to represent the CycleFold witness.
#[derive(Debug, Clone)]
pub struct CycleFoldWitnessVar<C: CurveGroup> {
pub E: Vec<NonNativeUintVar<CF2<C>>>,
pub rE: NonNativeUintVar<CF2<C>>,
pub W: Vec<NonNativeUintVar<CF2<C>>>,
pub rW: NonNativeUintVar<CF2<C>>,
}
impl<C> AllocVar<CycleFoldWitness<C>, CF2<C>> for CycleFoldWitnessVar<C>
where
C: CurveGroup,
<C as ark_ec::CurveGroup>::BaseField: PrimeField,
{
fn new_variable<T: Borrow<CycleFoldWitness<C>>>(
cs: impl Into<Namespace<CF2<C>>>,
f: impl FnOnce() -> Result<T, SynthesisError>,
mode: AllocationMode,
) -> Result<Self, SynthesisError> {
f().and_then(|val| {
let cs = cs.into();
let E = Vec::new_variable(cs.clone(), || Ok(val.borrow().E.clone()), mode)?;
let rE = NonNativeUintVar::new_variable(cs.clone(), || Ok(val.borrow().rE), mode)?;
let W = Vec::new_variable(cs.clone(), || Ok(val.borrow().W.clone()), mode)?;
let rW = NonNativeUintVar::new_variable(cs.clone(), || Ok(val.borrow().rW), mode)?;
Ok(Self { E, rE, W, rW })
})
}
}
/// Circuit that implements the in-circuit checks needed for the onchain (Ethereum's EVM)
/// verification.
#[derive(Clone, Debug)]
@ -262,6 +228,7 @@ where
<C1 as Group>::ScalarField: Absorb,
<C1 as CurveGroup>::BaseField: PrimeField,
{
/// returns an instance of the DeciderEthCircuit from the given Nova struct
pub fn from_nova<FC: FCircuit<C1::ScalarField>>(
nova: Nova<C1, GC1, C2, GC2, FC, CS1, CS2, H>,
) -> Result<Self, Error> {
@ -441,7 +408,7 @@ where
(u_i.x[0]).enforce_equal(&u_i_x)?;
#[cfg(feature = "light-test")]
println!("[WARNING]: Running with the 'light-test' feature, skipping the big part of the DeciderEthCircuit.\n Only for testing purposes.");
log::warn!("[WARNING]: Running with the 'light-test' feature, skipping the big part of the DeciderEthCircuit.\n Only for testing purposes.");
// The following two checks (and their respective allocations) are disabled for normal
// tests since they take several millions of constraints and would take several minutes
@ -453,7 +420,9 @@ where
// `#[cfg(not(test))]`
use crate::commitment::pedersen::PedersenGadget;
use crate::folding::{
circuits::cyclefold::{CycleFoldCommittedInstanceVar, CycleFoldConfig},
circuits::cyclefold::{
CycleFoldCommittedInstanceVar, CycleFoldConfig, CycleFoldWitnessVar,
},
nova::NovaCycleFoldConfig,
};
use ark_r1cs_std::ToBitsGadget;
@ -527,6 +496,7 @@ where
// Check 7 is temporary disabled due
// https://github.com/privacy-scaling-explorations/sonobe/issues/80
log::warn!("[WARNING]: issue #80 (https://github.com/privacy-scaling-explorations/sonobe/issues/80) is not resolved yet.");
//
// 7. check eval_W==p_W(c_W) and eval_E==p_E(c_E)
// let incircuit_eval_W = evaluate_gadget::<CF1<C1>>(W_i1.W, incircuit_c_W)?;

+ 4
- 1
folding-schemes/src/folding/nova/mod.rs

@ -42,12 +42,15 @@ use circuits::{AugmentedFCircuit, ChallengeGadget};
use nifs::NIFS;
use traits::NovaR1CS;
struct NovaCycleFoldConfig<C: CurveGroup> {
pub struct NovaCycleFoldConfig<C: CurveGroup> {
_c: PhantomData<C>,
}
impl<C: CurveGroup> CycleFoldConfig for NovaCycleFoldConfig<C> {
const RANDOMNESS_BIT_LENGTH: usize = NOVA_N_BITS_RO;
// Number of points to be folded in the CycleFold circuit, in Nova's case, this is a fixed
// amount:
// 2 points to be folded.
const N_INPUT_POINTS: usize = 2;
type C = C;
type F = C::BaseField;

+ 32
- 0
folding-schemes/src/utils/gadgets.rs

@ -107,3 +107,35 @@ impl MatrixGadget> for SparseMatrixVar> {
.collect())
}
}
/// Interprets the given vector v as the evaluations of a dense multilinear extension of n_vars,
/// and evaluates it at the given point. This method mimics the behavior of
/// `utils/mle.rs#dense_vec_to_dense_mle` + `DenseMultilinearExtension::evaluate` but in R1CS
/// constraints, since dense multilinear extensions are not supported in ark_r1cs_std.
pub fn eval_mle<F: PrimeField>(
// n_vars indicates the number of variables in the MLE
n_vars: usize,
// v is the vector of the evaluations of the dense multilinear extension (MLE)
v: Vec<FpVar<F>>,
// point is the point at which we want to evaluate the MLE
point: Vec<FpVar<F>>,
) -> FpVar<F> {
// pad to 2^n_vars
let mut poly: Vec<FpVar<F>> = [
v.to_owned(),
std::iter::repeat(FpVar::zero())
.take((1 << n_vars) - v.len())
.collect(),
]
.concat();
for i in 1..n_vars + 1 {
let r = point[i - 1].clone();
for b in 0..(1 << (n_vars - 1)) {
let left = poly[b << 1].clone();
let right = poly[(b << 1) + 1].clone();
poly[b] = left.clone() + r.clone() * (right - left);
}
}
poly[0].clone()
}

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