arnaucube
arnaucube/sonobePublic Self-hosted repository
sonobe/folding-schemes/src/folding/hypernova/circuits.rs
folding-schemes/src/folding/hypernova/circuits.rsRaw
   1/// Implementation of [HyperNova](https://eprint.iacr.org/2023/573.pdf) circuits
   2use ark_crypto_primitives::sponge::{
   3    constraints::CryptographicSpongeVar,
   4    poseidon::{constraints::PoseidonSpongeVar, PoseidonSponge},
   5    CryptographicSponge,
   6};
   7use ark_crypto_primitives::sponge::{poseidon::PoseidonConfig, Absorb};
   8use ark_ec::{CurveGroup, Group};
   9use ark_ff::PrimeField;
  10use ark_r1cs_std::{
  11    alloc::{AllocVar, AllocationMode},
  12    boolean::Boolean,
  13    eq::EqGadget,
  14    fields::{fp::FpVar, FieldVar},
  15    groups::GroupOpsBounds,
  16    prelude::CurveVar,
  17    R1CSVar, ToConstraintFieldGadget,
  18};
  19use ark_relations::r1cs::{
  20    ConstraintSynthesizer, ConstraintSystem, ConstraintSystemRef, Namespace, SynthesisError,
  21};
  22use ark_std::{fmt::Debug, ops::Neg, One, Zero};
  23use core::{borrow::Borrow, marker::PhantomData};
  24
  25use super::{
  26    cccs::CCCS,
  27    lcccs::LCCCS,
  28    nimfs::{NIMFSProof, NIMFS},
  29    Witness,
  30};
  31use crate::constants::N_BITS_RO;
  32use crate::folding::{
  33    circuits::cyclefold::{
  34        CycleFoldChallengeGadget, CycleFoldCommittedInstanceVar, NIFSFullGadget, CF_IO_LEN,
  35    },
  36    circuits::{
  37        nonnative::{affine::NonNativeAffineVar, uint::NonNativeUintVar},
  38        sum_check::{IOPProofVar, SumCheckVerifierGadget, VPAuxInfoVar},
  39        utils::EqEvalGadget,
  40        CF1, CF2,
  41    },
  42    nova::{get_r1cs_from_cs, CommittedInstance},
  43};
  44use crate::frontend::FCircuit;
  45use crate::utils::virtual_polynomial::VPAuxInfo;
  46use crate::Error;
  47use crate::{
  48    arith::{ccs::CCS, r1cs::extract_r1cs},
  49    transcript::TranscriptVar,
  50};
  51
  52/// Committed CCS instance
  53#[derive(Debug, Clone)]
  54pub struct CCCSVar<C: CurveGroup>
  55where
  56    <C as CurveGroup>::BaseField: PrimeField,
  57{
  58    // Commitment to witness
  59    pub C: NonNativeAffineVar<C>,
  60    // Public io
  61    pub x: Vec<FpVar<CF1<C>>>,
  62}
  63impl<C> AllocVar<CCCS<C>, CF1<C>> for CCCSVar<C>
  64where
  65    C: CurveGroup,
  66    <C as ark_ec::CurveGroup>::BaseField: PrimeField,
  67{
  68    fn new_variable<T: Borrow<CCCS<C>>>(
  69        cs: impl Into<Namespace<CF1<C>>>,
  70        f: impl FnOnce() -> Result<T, SynthesisError>,
  71        mode: AllocationMode,
  72    ) -> Result<Self, SynthesisError> {
  73        f().and_then(|val| {
  74            let cs = cs.into();
  75
  76            let C = NonNativeAffineVar::<C>::new_variable(cs.clone(), || Ok(val.borrow().C), mode)?;
  77            let x: Vec<FpVar<C::ScalarField>> =
  78                Vec::new_variable(cs.clone(), || Ok(val.borrow().x.clone()), mode)?;
  79
  80            Ok(Self { C, x })
  81        })
  82    }
  83}
  84
  85/// Linearized Committed CCS instance
  86#[derive(Debug, Clone)]
  87pub struct LCCCSVar<C: CurveGroup>
  88where
  89    <C as CurveGroup>::BaseField: PrimeField,
  90{
  91    // Commitment to witness
  92    pub C: NonNativeAffineVar<C>,
  93    // Relaxation factor of z for folded LCCCS
  94    pub u: FpVar<CF1<C>>,
  95    // Public io
  96    pub x: Vec<FpVar<CF1<C>>>,
  97    // Random evaluation point for the v_i
  98    pub r_x: Vec<FpVar<CF1<C>>>,
  99    // Vector of v_i
 100    pub v: Vec<FpVar<CF1<C>>>,
 101}
 102impl<C> AllocVar<LCCCS<C>, CF1<C>> for LCCCSVar<C>
 103where
 104    C: CurveGroup,
 105    <C as ark_ec::CurveGroup>::BaseField: PrimeField,
 106{
 107    fn new_variable<T: Borrow<LCCCS<C>>>(
 108        cs: impl Into<Namespace<CF1<C>>>,
 109        f: impl FnOnce() -> Result<T, SynthesisError>,
 110        mode: AllocationMode,
 111    ) -> Result<Self, SynthesisError> {
 112        f().and_then(|val| {
 113            let cs = cs.into();
 114
 115            let C = NonNativeAffineVar::<C>::new_variable(cs.clone(), || Ok(val.borrow().C), mode)?;
 116            let u = FpVar::<C::ScalarField>::new_variable(cs.clone(), || Ok(val.borrow().u), mode)?;
 117            let x: Vec<FpVar<C::ScalarField>> =
 118                Vec::new_variable(cs.clone(), || Ok(val.borrow().x.clone()), mode)?;
 119            let r_x: Vec<FpVar<C::ScalarField>> =
 120                Vec::new_variable(cs.clone(), || Ok(val.borrow().r_x.clone()), mode)?;
 121            let v: Vec<FpVar<C::ScalarField>> =
 122                Vec::new_variable(cs.clone(), || Ok(val.borrow().v.clone()), mode)?;
 123
 124            Ok(Self { C, u, x, r_x, v })
 125        })
 126    }
 127}
 128
 129impl<C> LCCCSVar<C>
 130where
 131    C: CurveGroup,
 132    <C as Group>::ScalarField: Absorb,
 133    <C as ark_ec::CurveGroup>::BaseField: ark_ff::PrimeField,
 134{
 135    /// [`LCCCSVar`].hash implements the LCCCS instance hash compatible with the native
 136    /// implementation from LCCCS.hash.
 137    /// Returns `H(i, z_0, z_i, U_i)`, where `i` can be `i` but also `i+1`, and `U` is the LCCCS.
 138    /// Additionally it returns the vector of the field elements from the self parameters, so they
 139    /// can be reused in other gadgets avoiding recalculating (reconstraining) them.
 140    #[allow(clippy::type_complexity)]
 141    pub fn hash(
 142        self,
 143        sponge: &PoseidonSpongeVar<CF1<C>>,
 144        pp_hash: FpVar<CF1<C>>,
 145        i: FpVar<CF1<C>>,
 146        z_0: Vec<FpVar<CF1<C>>>,
 147        z_i: Vec<FpVar<CF1<C>>>,
 148    ) -> Result<(FpVar<CF1<C>>, Vec<FpVar<CF1<C>>>), SynthesisError> {
 149        let mut sponge = sponge.clone();
 150        let U_vec = [
 151            self.C.to_constraint_field()?,
 152            vec![self.u],
 153            self.x,
 154            self.r_x,
 155            self.v,
 156        ]
 157        .concat();
 158        sponge.absorb(&pp_hash)?;
 159        sponge.absorb(&i)?;
 160        sponge.absorb(&z_0)?;
 161        sponge.absorb(&z_i)?;
 162        sponge.absorb(&U_vec)?;
 163        Ok((sponge.squeeze_field_elements(1)?.pop().unwrap(), U_vec))
 164    }
 165}
 166
 167/// ProofVar defines a multifolding proof
 168#[derive(Debug)]
 169pub struct ProofVar<C: CurveGroup> {
 170    pub sc_proof: IOPProofVar<C::ScalarField>,
 171    #[allow(clippy::type_complexity)]
 172    pub sigmas_thetas: (Vec<Vec<FpVar<CF1<C>>>>, Vec<Vec<FpVar<CF1<C>>>>),
 173}
 174impl<C> AllocVar<NIMFSProof<C>, CF1<C>> for ProofVar<C>
 175where
 176    C: CurveGroup,
 177    <C as ark_ec::CurveGroup>::BaseField: PrimeField,
 178    <C as Group>::ScalarField: Absorb,
 179{
 180    fn new_variable<T: Borrow<NIMFSProof<C>>>(
 181        cs: impl Into<Namespace<CF1<C>>>,
 182        f: impl FnOnce() -> Result<T, SynthesisError>,
 183        mode: AllocationMode,
 184    ) -> Result<Self, SynthesisError> {
 185        f().and_then(|val| {
 186            let cs = cs.into();
 187
 188            let sc_proof = IOPProofVar::<C::ScalarField>::new_variable(
 189                cs.clone(),
 190                || Ok(val.borrow().sc_proof.clone()),
 191                mode,
 192            )?;
 193            let sigmas: Vec<Vec<FpVar<CF1<C>>>> = val
 194                .borrow()
 195                .sigmas_thetas
 196                .0
 197                .iter()
 198                .map(|sigmas_i| Vec::new_variable(cs.clone(), || Ok(sigmas_i.clone()), mode))
 199                .collect::<Result<Vec<Vec<FpVar<CF1<C>>>>, SynthesisError>>()?;
 200            let thetas: Vec<Vec<FpVar<CF1<C>>>> = val
 201                .borrow()
 202                .sigmas_thetas
 203                .1
 204                .iter()
 205                .map(|thetas_i| Vec::new_variable(cs.clone(), || Ok(thetas_i.clone()), mode))
 206                .collect::<Result<Vec<Vec<FpVar<CF1<C>>>>, SynthesisError>>()?;
 207
 208            Ok(Self {
 209                sc_proof,
 210                sigmas_thetas: (sigmas.clone(), thetas.clone()),
 211            })
 212        })
 213    }
 214}
 215
 216pub struct NIMFSGadget<C: CurveGroup> {
 217    _c: PhantomData<C>,
 218}
 219impl<C: CurveGroup> NIMFSGadget<C>
 220where
 221    <C as CurveGroup>::BaseField: PrimeField,
 222{
 223    /// Runs (in-circuit) the NIMFS.V, which outputs the new folded LCCCS instance together with
 224    /// the rho_bits, which will be used in other parts of the AugmentedFCircuit
 225    #[allow(clippy::type_complexity)]
 226    pub fn verify<S: CryptographicSponge, T: TranscriptVar<C::ScalarField, S>>(
 227        cs: ConstraintSystemRef<CF1<C>>,
 228        // only used the CCS params, not the matrices
 229        ccs: &CCS<C::ScalarField>,
 230        transcript: &mut T,
 231        running_instances: &[LCCCSVar<C>],
 232        new_instances: &[CCCSVar<C>],
 233        proof: ProofVar<C>,
 234        enabled: Boolean<C::ScalarField>,
 235    ) -> Result<(LCCCSVar<C>, Vec<Boolean<CF1<C>>>), SynthesisError> {
 236        // absorb instances to transcript
 237        for U_i in running_instances {
 238            let v = [
 239                U_i.C.to_constraint_field()?,
 240                vec![U_i.u.clone()],
 241                U_i.x.clone(),
 242                U_i.r_x.clone(),
 243                U_i.v.clone(),
 244            ]
 245            .concat();
 246            transcript.absorb(&v)?;
 247        }
 248        for u_i in new_instances {
 249            let v = [u_i.C.to_constraint_field()?, u_i.x.clone()].concat();
 250            transcript.absorb(&v)?;
 251        }
 252
 253        // get the challenges
 254        let gamma_scalar_raw = C::ScalarField::from_le_bytes_mod_order(b"gamma");
 255        let gamma_scalar: FpVar<CF1<C>> =
 256            FpVar::<CF1<C>>::new_constant(cs.clone(), gamma_scalar_raw)?;
 257        transcript.absorb(&gamma_scalar)?;
 258        let gamma: FpVar<CF1<C>> = transcript.get_challenge()?;
 259
 260        let beta_scalar_raw = C::ScalarField::from_le_bytes_mod_order(b"beta");
 261        let beta_scalar: FpVar<CF1<C>> =
 262            FpVar::<CF1<C>>::new_constant(cs.clone(), beta_scalar_raw)?;
 263        transcript.absorb(&beta_scalar)?;
 264        let beta: Vec<FpVar<CF1<C>>> = transcript.get_challenges(ccs.s)?;
 265
 266        let vp_aux_info_raw = VPAuxInfo::<C::ScalarField> {
 267            max_degree: ccs.d + 1,
 268            num_variables: ccs.s,
 269            phantom: PhantomData::<C::ScalarField>,
 270        };
 271        let vp_aux_info = VPAuxInfoVar::<CF1<C>>::new_witness(cs.clone(), || Ok(vp_aux_info_raw))?;
 272
 273        // sumcheck
 274        // first, compute the expected sumcheck sum: \sum gamma^j v_j
 275        let mut sum_v_j_gamma = FpVar::<CF1<C>>::zero();
 276        let mut gamma_j = FpVar::<C::ScalarField>::one();
 277        for running_instance in running_instances.iter() {
 278            for j in 0..running_instance.v.len() {
 279                gamma_j *= gamma.clone();
 280                sum_v_j_gamma += running_instance.v[j].clone() * gamma_j.clone();
 281            }
 282        }
 283
 284        // verify the interactive part of the sumcheck
 285        let (e_vars, r_vars) = SumCheckVerifierGadget::<C::ScalarField>::verify(
 286            &proof.sc_proof,
 287            &vp_aux_info,
 288            transcript,
 289            enabled.clone(),
 290        )?;
 291
 292        // extract the randomness from the sumcheck
 293        let r_x_prime = r_vars.clone();
 294
 295        // verify the claim c
 296        let computed_c = compute_c_gadget(
 297            cs.clone(),
 298            ccs,
 299            proof.sigmas_thetas.0.clone(), // sigmas
 300            proof.sigmas_thetas.1.clone(), // thetas
 301            gamma,
 302            beta,
 303            running_instances
 304                .iter()
 305                .map(|lcccs| lcccs.r_x.clone())
 306                .collect(),
 307            r_x_prime.clone(),
 308        )?;
 309        computed_c.conditional_enforce_equal(&e_vars[e_vars.len() - 1], &enabled)?;
 310
 311        // get the folding challenge
 312        let rho_scalar_raw = C::ScalarField::from_le_bytes_mod_order(b"rho");
 313        let rho_scalar: FpVar<CF1<C>> = FpVar::<CF1<C>>::new_constant(cs.clone(), rho_scalar_raw)?;
 314        transcript.absorb(&rho_scalar)?;
 315        let rho_bits: Vec<Boolean<CF1<C>>> = transcript.get_challenge_nbits(N_BITS_RO)?;
 316        let rho = Boolean::le_bits_to_fp_var(&rho_bits)?;
 317
 318        // return the folded instance, together with the rho_bits so they can be used in other
 319        // parts of the AugmentedFCircuit
 320        Ok((
 321            Self::fold(
 322                running_instances,
 323                new_instances,
 324                proof.sigmas_thetas,
 325                r_x_prime,
 326                rho,
 327            )?,
 328            rho_bits,
 329        ))
 330    }
 331
 332    /// Runs (in-circuit) the verifier side of the fold, computing the new folded LCCCS instance
 333    #[allow(clippy::type_complexity)]
 334    fn fold(
 335        lcccs: &[LCCCSVar<C>],
 336        cccs: &[CCCSVar<C>],
 337        sigmas_thetas: (Vec<Vec<FpVar<CF1<C>>>>, Vec<Vec<FpVar<CF1<C>>>>),
 338        r_x_prime: Vec<FpVar<CF1<C>>>,
 339        rho: FpVar<CF1<C>>,
 340    ) -> Result<LCCCSVar<C>, SynthesisError> {
 341        let (sigmas, thetas) = (sigmas_thetas.0.clone(), sigmas_thetas.1.clone());
 342        let mut u_folded: FpVar<CF1<C>> = FpVar::zero();
 343        let mut x_folded: Vec<FpVar<CF1<C>>> = vec![FpVar::zero(); lcccs[0].x.len()];
 344        let mut v_folded: Vec<FpVar<CF1<C>>> = vec![FpVar::zero(); sigmas[0].len()];
 345
 346        let mut rho_i = FpVar::one();
 347        for i in 0..(lcccs.len() + cccs.len()) {
 348            let u: FpVar<CF1<C>>;
 349            let x: Vec<FpVar<CF1<C>>>;
 350            let v: Vec<FpVar<CF1<C>>>;
 351            if i < lcccs.len() {
 352                u = lcccs[i].u.clone();
 353                x = lcccs[i].x.clone();
 354                v = sigmas[i].clone();
 355            } else {
 356                u = FpVar::one();
 357                x = cccs[i - lcccs.len()].x.clone();
 358                v = thetas[i - lcccs.len()].clone();
 359            }
 360
 361            u_folded += rho_i.clone() * u;
 362            x_folded = x_folded
 363                .iter()
 364                .zip(
 365                    x.iter()
 366                        .map(|x_i| x_i * rho_i.clone())
 367                        .collect::<Vec<FpVar<CF1<C>>>>(),
 368                )
 369                .map(|(a_i, b_i)| a_i + b_i)
 370                .collect();
 371
 372            v_folded = v_folded
 373                .iter()
 374                .zip(
 375                    v.iter()
 376                        .map(|x_i| x_i * rho_i.clone())
 377                        .collect::<Vec<FpVar<CF1<C>>>>(),
 378                )
 379                .map(|(a_i, b_i)| a_i + b_i)
 380                .collect();
 381
 382            rho_i *= rho.clone();
 383        }
 384
 385        Ok(LCCCSVar::<C> {
 386            C: lcccs[0].C.clone(), // WIP this will come from the cyclefold circuit
 387            u: u_folded,
 388            x: x_folded,
 389            r_x: r_x_prime,
 390            v: v_folded,
 391        })
 392    }
 393}
 394
 395/// Computes c from the step 5 in section 5 of HyperNova, adapted to multiple LCCCS & CCCS
 396/// instances:
 397/// $$
 398/// c = \sum_{i \in [\mu]} \left(\sum_{j \in [t]} \gamma^{i \cdot t + j} \cdot e_i \cdot \sigma_{i,j} \right)
 399/// + \sum_{k \in [\nu]} \gamma^{\mu \cdot t+k} \cdot e_k \cdot \left( \sum_{i=1}^q c_i \cdot \prod_{j \in S_i}
 400/// \theta_{k,j} \right)
 401/// $$
 402#[allow(clippy::too_many_arguments)]
 403fn compute_c_gadget<F: PrimeField>(
 404    cs: ConstraintSystemRef<F>,
 405    ccs: &CCS<F>,
 406    vec_sigmas: Vec<Vec<FpVar<F>>>,
 407    vec_thetas: Vec<Vec<FpVar<F>>>,
 408    gamma: FpVar<F>,
 409    beta: Vec<FpVar<F>>,
 410    vec_r_x: Vec<Vec<FpVar<F>>>,
 411    vec_r_x_prime: Vec<FpVar<F>>,
 412) -> Result<FpVar<F>, SynthesisError> {
 413    let mut e_lcccs = Vec::new();
 414    for r_x in vec_r_x.iter() {
 415        e_lcccs.push(EqEvalGadget::eq_eval(r_x, &vec_r_x_prime)?);
 416    }
 417
 418    let mut c = FpVar::<F>::zero();
 419    let mut current_gamma = FpVar::<F>::one();
 420    for i in 0..vec_sigmas.len() {
 421        for j in 0..ccs.t {
 422            c += current_gamma.clone() * e_lcccs[i].clone() * vec_sigmas[i][j].clone();
 423            current_gamma *= gamma.clone();
 424        }
 425    }
 426
 427    let ccs_c = Vec::<FpVar<F>>::new_constant(cs.clone(), ccs.c.clone())?;
 428    let e_k = EqEvalGadget::eq_eval(&beta, &vec_r_x_prime)?;
 429    #[allow(clippy::needless_range_loop)]
 430    for k in 0..vec_thetas.len() {
 431        let mut sum = FpVar::<F>::zero();
 432        for i in 0..ccs.q {
 433            let mut prod = FpVar::<F>::one();
 434            for j in ccs.S[i].clone() {
 435                prod *= vec_thetas[k][j].clone();
 436            }
 437            sum += ccs_c[i].clone() * prod;
 438        }
 439        c += current_gamma.clone() * e_k.clone() * sum;
 440        current_gamma *= gamma.clone();
 441    }
 442    Ok(c)
 443}
 444
 445#[derive(Debug, Clone)]
 446pub struct AugmentedFCircuit<
 447    C1: CurveGroup,
 448    C2: CurveGroup,
 449    GC2: CurveVar<C2, CF2<C2>>,
 450    FC: FCircuit<CF1<C1>>,
 451> where
 452    for<'a> &'a GC2: GroupOpsBounds<'a, C2, GC2>,
 453{
 454    pub _c2: PhantomData<C2>,
 455    pub _gc2: PhantomData<GC2>,
 456    pub poseidon_config: PoseidonConfig<CF1<C1>>,
 457    pub ccs: CCS<C1::ScalarField>, // CCS of the AugmentedFCircuit
 458    pub pp_hash: Option<CF1<C1>>,
 459    pub i: Option<CF1<C1>>,
 460    pub i_usize: Option<usize>,
 461    pub z_0: Option<Vec<C1::ScalarField>>,
 462    pub z_i: Option<Vec<C1::ScalarField>>,
 463    pub external_inputs: Option<Vec<C1::ScalarField>>,
 464    pub u_i_C: Option<C1>, // u_i.C
 465    pub U_i: Option<LCCCS<C1>>,
 466    pub U_i1_C: Option<C1>, // U_{i+1}.C
 467    pub F: FC,              // F circuit
 468    pub x: Option<CF1<C1>>, // public input (u_{i+1}.x[0])
 469    pub nimfs_proof: Option<NIMFSProof<C1>>,
 470
 471    // cyclefold verifier on C1
 472    pub cf_u_i_cmW: Option<C2>,                // input, cf_u_i.cmW
 473    pub cf_U_i: Option<CommittedInstance<C2>>, // input, RelaxedR1CS CycleFold instance
 474    pub cf_x: Option<CF1<C1>>,                 // public input (cf_u_{i+1}.x[1])
 475    pub cf_cmT: Option<C2>,
 476}
 477
 478impl<C1, C2, GC2, FC> AugmentedFCircuit<C1, C2, GC2, FC>
 479where
 480    C1: CurveGroup,
 481    C2: CurveGroup,
 482    GC2: CurveVar<C2, CF2<C2>> + ToConstraintFieldGadget<CF2<C2>>,
 483    FC: FCircuit<CF1<C1>>,
 484    <C1 as CurveGroup>::BaseField: PrimeField,
 485    <C2 as CurveGroup>::BaseField: PrimeField,
 486    <C1 as Group>::ScalarField: Absorb,
 487    <C2 as Group>::ScalarField: Absorb,
 488    C1: CurveGroup<BaseField = C2::ScalarField, ScalarField = C2::BaseField>,
 489    for<'a> &'a GC2: GroupOpsBounds<'a, C2, GC2>,
 490{
 491    pub fn default(
 492        poseidon_config: &PoseidonConfig<CF1<C1>>,
 493        F_circuit: FC,
 494        ccs: CCS<C1::ScalarField>,
 495    ) -> Self {
 496        Self {
 497            _c2: PhantomData,
 498            _gc2: PhantomData,
 499            poseidon_config: poseidon_config.clone(),
 500            ccs,
 501            pp_hash: None,
 502            i: None,
 503            i_usize: None,
 504            z_0: None,
 505            z_i: None,
 506            external_inputs: None,
 507            u_i_C: None,
 508            U_i: None,
 509            U_i1_C: None,
 510            F: F_circuit,
 511            x: None,
 512            nimfs_proof: None,
 513            cf_u_i_cmW: None,
 514            cf_U_i: None,
 515            cf_x: None,
 516            cf_cmT: None,
 517        }
 518    }
 519
 520    pub fn empty(
 521        poseidon_config: &PoseidonConfig<CF1<C1>>,
 522        F_circuit: FC,
 523        ccs: Option<CCS<C1::ScalarField>>,
 524    ) -> Result<Self, Error> {
 525        let initial_ccs = CCS {
 526            // m, n, s, s_prime and M will be overwritten by the `upper_bound_ccs' method
 527            m: 0,
 528            n: 0,
 529            l: 2, // io_len
 530            s: 1,
 531            s_prime: 1,
 532            t: 3, // note: this is only supports R1CS for the moment
 533            q: 2,
 534            d: 2,
 535            S: vec![vec![0, 1], vec![2]],
 536            c: vec![C1::ScalarField::one(), C1::ScalarField::one().neg()],
 537            M: vec![],
 538        };
 539        let mut augmented_f_circuit = Self::default(poseidon_config, F_circuit, initial_ccs);
 540        if ccs.is_some() {
 541            augmented_f_circuit.ccs = ccs.unwrap();
 542        } else {
 543            augmented_f_circuit.ccs = augmented_f_circuit.upper_bound_ccs()?;
 544        }
 545        Ok(augmented_f_circuit)
 546    }
 547
 548    /// This method computes the CCS parameters. This is used because there is a circular
 549    /// dependency between the AugmentedFCircuit CCS and the CCS parameters m & n & s & s'.
 550    /// For a stable FCircuit circuit, the CCS parameters can be computed in advance and can be
 551    /// feed in as parameter for the AugmentedFCircuit::empty method to avoid computing them there.
 552    pub fn upper_bound_ccs(&self) -> Result<CCS<C1::ScalarField>, Error> {
 553        let r1cs = get_r1cs_from_cs::<CF1<C1>>(self.clone()).unwrap();
 554        let ccs = CCS::from_r1cs(r1cs.clone());
 555
 556        let z_0 = vec![C1::ScalarField::zero(); self.F.state_len()];
 557        let W_i = Witness::<C1::ScalarField>::dummy(&ccs);
 558        let U_i = LCCCS::<C1>::dummy(ccs.l, ccs.t, ccs.s);
 559        let w_i = W_i.clone();
 560        let u_i = CCCS::<C1>::dummy(ccs.l);
 561
 562        let mut transcript_p: PoseidonSponge<C1::ScalarField> =
 563            PoseidonSponge::<C1::ScalarField>::new(&self.poseidon_config.clone());
 564        // since this is only for the number of constraints, no need to absorb the pp_hash here
 565        let (nimfs_proof, U_i1, _, _) = NIMFS::<C1, PoseidonSponge<C1::ScalarField>>::prove(
 566            &mut transcript_p,
 567            &ccs,
 568            &[U_i.clone()],
 569            &[u_i.clone()],
 570            &[W_i.clone()],
 571            &[w_i.clone()],
 572        )?;
 573
 574        let augmented_f_circuit = Self {
 575            _c2: PhantomData,
 576            _gc2: PhantomData,
 577            poseidon_config: self.poseidon_config.clone(),
 578            ccs: ccs.clone(),
 579            pp_hash: Some(C1::ScalarField::zero()),
 580            i: Some(C1::ScalarField::zero()),
 581            i_usize: Some(0),
 582            z_0: Some(z_0.clone()),
 583            z_i: Some(z_0.clone()),
 584            external_inputs: Some(vec![]),
 585            u_i_C: Some(u_i.C),
 586            U_i: Some(U_i.clone()),
 587            U_i1_C: Some(U_i1.C),
 588            F: self.F.clone(),
 589            x: Some(C1::ScalarField::zero()),
 590            nimfs_proof: Some(nimfs_proof),
 591            // cyclefold values
 592            cf_u_i_cmW: None,
 593            cf_U_i: None,
 594            cf_x: None,
 595            cf_cmT: None,
 596        };
 597
 598        Ok(augmented_f_circuit.compute_cs_ccs()?.1)
 599    }
 600
 601    /// Returns the cs (ConstraintSystem) and the CCS out of the AugmentedFCircuit
 602    #[allow(clippy::type_complexity)]
 603    pub fn compute_cs_ccs(
 604        &self,
 605    ) -> Result<(ConstraintSystem<C1::ScalarField>, CCS<C1::ScalarField>), Error> {
 606        let cs = ConstraintSystem::<C1::ScalarField>::new_ref();
 607        self.clone().generate_constraints(cs.clone())?;
 608        cs.finalize();
 609        let cs = cs.into_inner().ok_or(Error::NoInnerConstraintSystem)?;
 610        let r1cs = extract_r1cs::<C1::ScalarField>(&cs);
 611        let ccs = CCS::from_r1cs(r1cs.clone());
 612
 613        Ok((cs, ccs))
 614    }
 615}
 616
 617impl<C1, C2, GC2, FC> ConstraintSynthesizer<CF1<C1>> for AugmentedFCircuit<C1, C2, GC2, FC>
 618where
 619    C1: CurveGroup,
 620    C2: CurveGroup,
 621    GC2: CurveVar<C2, CF2<C2>> + ToConstraintFieldGadget<CF2<C2>>,
 622    FC: FCircuit<CF1<C1>>,
 623    <C1 as CurveGroup>::BaseField: PrimeField,
 624    <C2 as CurveGroup>::BaseField: PrimeField,
 625    <C1 as Group>::ScalarField: Absorb,
 626    <C2 as Group>::ScalarField: Absorb,
 627    C1: CurveGroup<BaseField = C2::ScalarField, ScalarField = C2::BaseField>,
 628    for<'a> &'a GC2: GroupOpsBounds<'a, C2, GC2>,
 629{
 630    fn generate_constraints(self, cs: ConstraintSystemRef<CF1<C1>>) -> Result<(), SynthesisError> {
 631        let pp_hash = FpVar::<CF1<C1>>::new_witness(cs.clone(), || {
 632            Ok(self.pp_hash.unwrap_or_else(CF1::<C1>::zero))
 633        })?;
 634        let i = FpVar::<CF1<C1>>::new_witness(cs.clone(), || {
 635            Ok(self.i.unwrap_or_else(CF1::<C1>::zero))
 636        })?;
 637        let z_0 = Vec::<FpVar<CF1<C1>>>::new_witness(cs.clone(), || {
 638            Ok(self
 639                .z_0
 640                .unwrap_or(vec![CF1::<C1>::zero(); self.F.state_len()]))
 641        })?;
 642        let z_i = Vec::<FpVar<CF1<C1>>>::new_witness(cs.clone(), || {
 643            Ok(self
 644                .z_i
 645                .unwrap_or(vec![CF1::<C1>::zero(); self.F.state_len()]))
 646        })?;
 647        let external_inputs = Vec::<FpVar<CF1<C1>>>::new_witness(cs.clone(), || {
 648            Ok(self
 649                .external_inputs
 650                .unwrap_or(vec![CF1::<C1>::zero(); self.F.external_inputs_len()]))
 651        })?;
 652
 653        let U_dummy = LCCCS::<C1>::dummy(self.ccs.l, self.ccs.t, self.ccs.s);
 654
 655        let U_i =
 656            LCCCSVar::<C1>::new_witness(cs.clone(), || Ok(self.U_i.unwrap_or(U_dummy.clone())))?;
 657        let U_i1_C = NonNativeAffineVar::new_witness(cs.clone(), || {
 658            Ok(self.U_i1_C.unwrap_or_else(C1::zero))
 659        })?;
 660        let mu = 1; // Note: at this commit, only 2-to-1 instance fold is supported
 661        let nu = 1;
 662        let nimfs_proof_dummy = NIMFSProof::<C1>::dummy(&self.ccs, mu, nu);
 663        let nimfs_proof = ProofVar::<C1>::new_witness(cs.clone(), || {
 664            Ok(self.nimfs_proof.unwrap_or(nimfs_proof_dummy))
 665        })?;
 666
 667        let cf_u_dummy = CommittedInstance::dummy(CF_IO_LEN);
 668        let cf_U_i = CycleFoldCommittedInstanceVar::<C2, GC2>::new_witness(cs.clone(), || {
 669            Ok(self.cf_U_i.unwrap_or(cf_u_dummy.clone()))
 670        })?;
 671        let cf_cmT = GC2::new_witness(cs.clone(), || Ok(self.cf_cmT.unwrap_or_else(C2::zero)))?;
 672
 673        let sponge = PoseidonSpongeVar::<C1::ScalarField>::new(cs.clone(), &self.poseidon_config);
 674
 675        // get z_{i+1} from the F circuit
 676        let i_usize = self.i_usize.unwrap_or(0);
 677        let z_i1 =
 678            self.F
 679                .generate_step_constraints(cs.clone(), i_usize, z_i.clone(), external_inputs)?;
 680
 681        let is_basecase = i.is_zero()?;
 682        let is_not_basecase = is_basecase.not();
 683
 684        // Primary Part
 685        // P.1. Compute u_i.x
 686        // u_i.x[0] = H(i, z_0, z_i, U_i)
 687        let (u_i_x, _) = U_i.clone().hash(
 688            &sponge,
 689            pp_hash.clone(),
 690            i.clone(),
 691            z_0.clone(),
 692            z_i.clone(),
 693        )?;
 694        // u_i.x[1] = H(cf_U_i)
 695        let (cf_u_i_x, cf_U_i_vec) = cf_U_i.clone().hash(&sponge, pp_hash.clone())?;
 696
 697        // P.2. Construct u_i
 698        let u_i = CCCSVar::<C1> {
 699            // u_i.C is provided by the prover as witness
 700            C: NonNativeAffineVar::<C1>::new_witness(cs.clone(), || {
 701                Ok(self.u_i_C.unwrap_or(C1::zero()))
 702            })?,
 703            // u_i.x is computed in step 1
 704            x: vec![u_i_x, cf_u_i_x],
 705        };
 706
 707        // P.3. NIMFS.verify, obtains U_{i+1} by folding [U_i] & [u_i].
 708        // Notice that NIMFSGadget::fold_committed_instance does not fold C. We set `U_i1.C` to
 709        // unconstrained witnesses `U_i1_C` respectively. Its correctness will be checked on the
 710        // other curve.
 711        let mut transcript = PoseidonSpongeVar::new(cs.clone(), &self.poseidon_config);
 712        transcript.absorb(&pp_hash)?;
 713        let (mut U_i1, rho_bits) = NIMFSGadget::<C1>::verify(
 714            cs.clone(),
 715            &self.ccs.clone(),
 716            &mut transcript,
 717            &[U_i.clone()],
 718            &[u_i.clone()],
 719            nimfs_proof,
 720            is_not_basecase.clone(),
 721        )?;
 722        U_i1.C = U_i1_C;
 723
 724        // P.4.a compute and check the first output of F'
 725        let (u_i1_x, _) = U_i1.clone().hash(
 726            &sponge,
 727            pp_hash.clone(),
 728            i + FpVar::<CF1<C1>>::one(),
 729            z_0.clone(),
 730            z_i1.clone(),
 731        )?;
 732        let (u_i1_x_base, _) = LCCCSVar::new_constant(cs.clone(), U_dummy)?.hash(
 733            &sponge,
 734            pp_hash.clone(),
 735            FpVar::<CF1<C1>>::one(),
 736            z_0.clone(),
 737            z_i1.clone(),
 738        )?;
 739        let x = FpVar::new_input(cs.clone(), || Ok(self.x.unwrap_or(u_i1_x_base.value()?)))?;
 740        x.enforce_equal(&is_basecase.select(&u_i1_x_base, &u_i1_x)?)?;
 741
 742        // convert rho_bits to a `NonNativeFieldVar`
 743        let rho_nonnat = {
 744            let mut bits = rho_bits;
 745            bits.resize(C1::BaseField::MODULUS_BIT_SIZE as usize, Boolean::FALSE);
 746            NonNativeUintVar::from(&bits)
 747        };
 748
 749        // CycleFold part
 750        // C.1. Compute cf1_u_i.x and cf2_u_i.x
 751        let cf_x = vec![
 752            rho_nonnat, U_i.C.x, U_i.C.y, u_i.C.x, u_i.C.y, U_i1.C.x, U_i1.C.y,
 753        ];
 754
 755        // ensure that cf_u has as public inputs the C from main instances U_i, u_i, U_i+1
 756        // coordinates of the commitments.
 757        // C.2. Construct `cf_u_i`
 758        let cf_u_i = CycleFoldCommittedInstanceVar {
 759            // cf1_u_i.cmE = 0. Notice that we enforce cmE to be equal to 0 since it is allocated
 760            // as 0.
 761            cmE: GC2::zero(),
 762            // cf1_u_i.u = 1
 763            u: NonNativeUintVar::new_constant(cs.clone(), C1::BaseField::one())?,
 764            // cf_u_i.cmW is provided by the prover as witness
 765            cmW: GC2::new_witness(cs.clone(), || Ok(self.cf_u_i_cmW.unwrap_or(C2::zero())))?,
 766            // cf_u_i.x is computed in step 1
 767            x: cf_x,
 768        };
 769
 770        // C.3. nifs.verify (fold_committed_instance), obtains cf_U_{i+1} by folding cf_u_i & cf_U_i.
 771        // compute cf_r = H(cf_u_i, cf_U_i, cf_cmT)
 772        // cf_r_bits is denoted by rho* in the paper.
 773        let cf_r_bits = CycleFoldChallengeGadget::<C2, GC2>::get_challenge_gadget(
 774            &mut transcript,
 775            pp_hash.clone(),
 776            cf_U_i_vec,
 777            cf_u_i.clone(),
 778            cf_cmT.clone(),
 779        )?;
 780        // Convert cf_r_bits to a `NonNativeFieldVar`
 781        let cf_r_nonnat = {
 782            let mut bits = cf_r_bits.clone();
 783            bits.resize(C1::BaseField::MODULUS_BIT_SIZE as usize, Boolean::FALSE);
 784            NonNativeUintVar::from(&bits)
 785        };
 786        // Fold cf1_u_i & cf_U_i into cf1_U_{i+1}
 787        let cf_U_i1 = NIFSFullGadget::<C2, GC2>::fold_committed_instance(
 788            cf_r_bits,
 789            cf_r_nonnat,
 790            cf_cmT,
 791            cf_U_i,
 792            cf_u_i,
 793        )?;
 794
 795        // Back to Primary Part
 796        // P.4.b compute and check the second output of F'
 797        // Base case: u_{i+1}.x[1] == H(cf_U_{\bot})
 798        // Non-base case: u_{i+1}.x[1] == H(cf_U_{i+1})
 799        let (cf_u_i1_x, _) = cf_U_i1.clone().hash(&sponge, pp_hash.clone())?;
 800        let (cf_u_i1_x_base, _) =
 801            CycleFoldCommittedInstanceVar::new_constant(cs.clone(), cf_u_dummy)?
 802                .hash(&sponge, pp_hash)?;
 803        let cf_x = FpVar::new_input(cs.clone(), || {
 804            Ok(self.cf_x.unwrap_or(cf_u_i1_x_base.value()?))
 805        })?;
 806        cf_x.enforce_equal(&is_basecase.select(&cf_u_i1_x_base, &cf_u_i1_x)?)?;
 807
 808        Ok(())
 809    }
 810}
 811
 812#[cfg(test)]
 813mod tests {
 814    use ark_bn254::{constraints::GVar, Fq, Fr, G1Projective as Projective};
 815    use ark_ff::BigInteger;
 816    use ark_grumpkin::{constraints::GVar as GVar2, Projective as Projective2};
 817    use ark_std::{test_rng, UniformRand};
 818    use std::time::Instant;
 819
 820    use super::*;
 821    use crate::{
 822        arith::{
 823            ccs::tests::{get_test_ccs, get_test_z},
 824            r1cs::extract_w_x,
 825        },
 826        commitment::{pedersen::Pedersen, CommitmentScheme},
 827        folding::{
 828            circuits::cyclefold::{fold_cyclefold_circuit, CycleFoldCircuit},
 829            hypernova::utils::{compute_c, compute_sigmas_thetas},
 830            nova::{traits::NovaR1CS, Witness as NovaWitness},
 831        },
 832        frontend::tests::CubicFCircuit,
 833        transcript::poseidon::poseidon_canonical_config,
 834        utils::get_cm_coordinates,
 835    };
 836
 837    #[test]
 838    pub fn test_compute_c_gadget() {
 839        // number of LCCCS & CCCS instances to fold in a single step
 840        let mu = 32;
 841        let nu = 42;
 842
 843        let mut z_lcccs = Vec::new();
 844        for i in 0..mu {
 845            let z = get_test_z(i + 3);
 846            z_lcccs.push(z);
 847        }
 848        let mut z_cccs = Vec::new();
 849        for i in 0..nu {
 850            let z = get_test_z(i + 3);
 851            z_cccs.push(z);
 852        }
 853
 854        let ccs: CCS<Fr> = get_test_ccs();
 855
 856        let mut rng = test_rng();
 857        let gamma: Fr = Fr::rand(&mut rng);
 858        let beta: Vec<Fr> = (0..ccs.s).map(|_| Fr::rand(&mut rng)).collect();
 859        let r_x_prime: Vec<Fr> = (0..ccs.s).map(|_| Fr::rand(&mut rng)).collect();
 860
 861        let (pedersen_params, _) =
 862            Pedersen::<Projective>::setup(&mut rng, ccs.n - ccs.l - 1).unwrap();
 863
 864        // Create the LCCCS instances out of z_lcccs
 865        let mut lcccs_instances = Vec::new();
 866        for z_i in z_lcccs.iter() {
 867            let (inst, _) = ccs
 868                .to_lcccs::<_, _, Pedersen<Projective>>(&mut rng, &pedersen_params, z_i)
 869                .unwrap();
 870            lcccs_instances.push(inst);
 871        }
 872        // Create the CCCS instance out of z_cccs
 873        let mut cccs_instances = Vec::new();
 874        for z_i in z_cccs.iter() {
 875            let (inst, _) = ccs
 876                .to_cccs::<_, _, Pedersen<Projective>>(&mut rng, &pedersen_params, z_i)
 877                .unwrap();
 878            cccs_instances.push(inst);
 879        }
 880
 881        let sigmas_thetas = compute_sigmas_thetas(&ccs, &z_lcccs, &z_cccs, &r_x_prime).unwrap();
 882
 883        let expected_c = compute_c(
 884            &ccs,
 885            &sigmas_thetas,
 886            gamma,
 887            &beta,
 888            &lcccs_instances
 889                .iter()
 890                .map(|lcccs| lcccs.r_x.clone())
 891                .collect(),
 892            &r_x_prime,
 893        )
 894        .unwrap();
 895
 896        let cs = ConstraintSystem::<Fr>::new_ref();
 897        let mut vec_sigmas = Vec::new();
 898        let mut vec_thetas = Vec::new();
 899        for sigmas in sigmas_thetas.0 {
 900            vec_sigmas
 901                .push(Vec::<FpVar<Fr>>::new_witness(cs.clone(), || Ok(sigmas.clone())).unwrap());
 902        }
 903        for thetas in sigmas_thetas.1 {
 904            vec_thetas
 905                .push(Vec::<FpVar<Fr>>::new_witness(cs.clone(), || Ok(thetas.clone())).unwrap());
 906        }
 907        let vec_r_x: Vec<Vec<FpVar<Fr>>> = lcccs_instances
 908            .iter()
 909            .map(|lcccs| {
 910                Vec::<FpVar<Fr>>::new_witness(cs.clone(), || Ok(lcccs.r_x.clone())).unwrap()
 911            })
 912            .collect();
 913        let vec_r_x_prime =
 914            Vec::<FpVar<Fr>>::new_witness(cs.clone(), || Ok(r_x_prime.clone())).unwrap();
 915        let gamma_var = FpVar::<Fr>::new_witness(cs.clone(), || Ok(gamma)).unwrap();
 916        let beta_var = Vec::<FpVar<Fr>>::new_witness(cs.clone(), || Ok(beta.clone())).unwrap();
 917
 918        let computed_c = compute_c_gadget(
 919            cs.clone(),
 920            &ccs,
 921            vec_sigmas,
 922            vec_thetas,
 923            gamma_var,
 924            beta_var,
 925            vec_r_x,
 926            vec_r_x_prime,
 927        )
 928        .unwrap();
 929
 930        assert_eq!(expected_c, computed_c.value().unwrap());
 931    }
 932
 933    /// Test that generates mu>1 and nu>1 instances, and folds them in a single multifolding step,
 934    /// to verify the folding in the NIMFSGadget circuit
 935    #[test]
 936    pub fn test_nimfs_gadget_verify() {
 937        let mut rng = test_rng();
 938
 939        // Create a basic CCS circuit
 940        let ccs = get_test_ccs::<Fr>();
 941        let (pedersen_params, _) =
 942            Pedersen::<Projective>::setup(&mut rng, ccs.n - ccs.l - 1).unwrap();
 943
 944        let mu = 32;
 945        let nu = 42;
 946
 947        // Generate a mu LCCCS & nu CCCS satisfying witness
 948        let mut z_lcccs = Vec::new();
 949        for i in 0..mu {
 950            let z = get_test_z(i + 3);
 951            z_lcccs.push(z);
 952        }
 953        let mut z_cccs = Vec::new();
 954        for i in 0..nu {
 955            let z = get_test_z(nu + i + 3);
 956            z_cccs.push(z);
 957        }
 958
 959        // Create the LCCCS instances out of z_lcccs
 960        let mut lcccs_instances = Vec::new();
 961        let mut w_lcccs = Vec::new();
 962        for z_i in z_lcccs.iter() {
 963            let (running_instance, w) = ccs
 964                .to_lcccs::<_, _, Pedersen<Projective>>(&mut rng, &pedersen_params, z_i)
 965                .unwrap();
 966            lcccs_instances.push(running_instance);
 967            w_lcccs.push(w);
 968        }
 969        // Create the CCCS instance out of z_cccs
 970        let mut cccs_instances = Vec::new();
 971        let mut w_cccs = Vec::new();
 972        for z_i in z_cccs.iter() {
 973            let (new_instance, w) = ccs
 974                .to_cccs::<_, _, Pedersen<Projective>>(&mut rng, &pedersen_params, z_i)
 975                .unwrap();
 976            cccs_instances.push(new_instance);
 977            w_cccs.push(w);
 978        }
 979
 980        // Prover's transcript
 981        let poseidon_config = poseidon_canonical_config::<Fr>();
 982        let mut transcript_p: PoseidonSponge<Fr> = PoseidonSponge::<Fr>::new(&poseidon_config);
 983
 984        // Run the prover side of the multifolding
 985        let (proof, folded_lcccs, folded_witness, _) =
 986            NIMFS::<Projective, PoseidonSponge<Fr>>::prove(
 987                &mut transcript_p,
 988                &ccs,
 989                &lcccs_instances,
 990                &cccs_instances,
 991                &w_lcccs,
 992                &w_cccs,
 993            )
 994            .unwrap();
 995
 996        // Verifier's transcript
 997        let mut transcript_v: PoseidonSponge<Fr> = PoseidonSponge::<Fr>::new(&poseidon_config);
 998
 999        // Run the verifier side of the multifolding
1000        let folded_lcccs_v = NIMFS::<Projective, PoseidonSponge<Fr>>::verify(
1001            &mut transcript_v,
1002            &ccs,
1003            &lcccs_instances,
1004            &cccs_instances,
1005            proof.clone(),
1006        )
1007        .unwrap();
1008        assert_eq!(folded_lcccs, folded_lcccs_v);
1009
1010        // Check that the folded LCCCS instance is a valid instance with respect to the folded witness
1011        folded_lcccs.check_relation(&ccs, &folded_witness).unwrap();
1012
1013        // allocate circuit inputs
1014        let cs = ConstraintSystem::<Fr>::new_ref();
1015        let lcccs_instancesVar =
1016            Vec::<LCCCSVar<Projective>>::new_witness(cs.clone(), || Ok(lcccs_instances.clone()))
1017                .unwrap();
1018        let cccs_instancesVar =
1019            Vec::<CCCSVar<Projective>>::new_witness(cs.clone(), || Ok(cccs_instances.clone()))
1020                .unwrap();
1021        let proofVar =
1022            ProofVar::<Projective>::new_witness(cs.clone(), || Ok(proof.clone())).unwrap();
1023        let mut transcriptVar = PoseidonSpongeVar::<Fr>::new(cs.clone(), &poseidon_config);
1024
1025        let enabled = Boolean::<Fr>::new_witness(cs.clone(), || Ok(true)).unwrap();
1026        let (folded_lcccsVar, _) = NIMFSGadget::<Projective>::verify(
1027            cs.clone(),
1028            &ccs,
1029            &mut transcriptVar,
1030            &lcccs_instancesVar,
1031            &cccs_instancesVar,
1032            proofVar,
1033            enabled,
1034        )
1035        .unwrap();
1036        assert!(cs.is_satisfied().unwrap());
1037        assert_eq!(folded_lcccsVar.u.value().unwrap(), folded_lcccs.u);
1038    }
1039
1040    /// test that checks the native LCCCS.hash vs the R1CS constraints version
1041    #[test]
1042    pub fn test_lcccs_hash() {
1043        let mut rng = test_rng();
1044        let poseidon_config = poseidon_canonical_config::<Fr>();
1045        let sponge = PoseidonSponge::<Fr>::new(&poseidon_config);
1046
1047        let ccs = get_test_ccs();
1048        let z1 = get_test_z::<Fr>(3);
1049
1050        let (pedersen_params, _) =
1051            Pedersen::<Projective>::setup(&mut rng, ccs.n - ccs.l - 1).unwrap();
1052        let pp_hash = Fr::from(42u32); // only for test
1053
1054        let i = Fr::from(3_u32);
1055        let z_0 = vec![Fr::from(3_u32)];
1056        let z_i = vec![Fr::from(3_u32)];
1057        let (lcccs, _) = ccs
1058            .to_lcccs::<_, _, Pedersen<Projective>>(&mut rng, &pedersen_params, &z1)
1059            .unwrap();
1060        let h = lcccs
1061            .clone()
1062            .hash(&sponge, pp_hash, i, z_0.clone(), z_i.clone());
1063
1064        let cs = ConstraintSystem::<Fr>::new_ref();
1065
1066        let spongeVar = PoseidonSpongeVar::<Fr>::new(cs.clone(), &poseidon_config);
1067        let pp_hashVar = FpVar::<Fr>::new_witness(cs.clone(), || Ok(pp_hash)).unwrap();
1068        let iVar = FpVar::<Fr>::new_witness(cs.clone(), || Ok(i)).unwrap();
1069        let z_0Var = Vec::<FpVar<Fr>>::new_witness(cs.clone(), || Ok(z_0.clone())).unwrap();
1070        let z_iVar = Vec::<FpVar<Fr>>::new_witness(cs.clone(), || Ok(z_i.clone())).unwrap();
1071        let lcccsVar = LCCCSVar::<Projective>::new_witness(cs.clone(), || Ok(lcccs)).unwrap();
1072        let (hVar, _) = lcccsVar
1073            .clone()
1074            .hash(
1075                &spongeVar,
1076                pp_hashVar,
1077                iVar.clone(),
1078                z_0Var.clone(),
1079                z_iVar.clone(),
1080            )
1081            .unwrap();
1082        assert!(cs.is_satisfied().unwrap());
1083
1084        // check that the natively computed and in-circuit computed hashes match
1085        assert_eq!(hVar.value().unwrap(), h);
1086    }
1087
1088    #[test]
1089    pub fn test_augmented_f_circuit() {
1090        let mut rng = test_rng();
1091        let poseidon_config = poseidon_canonical_config::<Fr>();
1092        let sponge = PoseidonSponge::<Fr>::new(&poseidon_config);
1093
1094        let start = Instant::now();
1095        let F_circuit = CubicFCircuit::<Fr>::new(()).unwrap();
1096        let mut augmented_f_circuit = AugmentedFCircuit::<
1097            Projective,
1098            Projective2,
1099            GVar2,
1100            CubicFCircuit<Fr>,
1101        >::empty(&poseidon_config, F_circuit, None)
1102        .unwrap();
1103        let ccs = augmented_f_circuit.ccs.clone();
1104        println!("AugmentedFCircuit & CCS generation: {:?}", start.elapsed());
1105        println!("CCS m x n: {} x {}", ccs.m, ccs.n);
1106
1107        // CycleFold circuit
1108        let cs2 = ConstraintSystem::<Fq>::new_ref();
1109        let cf_circuit = CycleFoldCircuit::<Projective, GVar>::empty();
1110        cf_circuit.generate_constraints(cs2.clone()).unwrap();
1111        cs2.finalize();
1112        let cs2 = cs2
1113            .into_inner()
1114            .ok_or(Error::NoInnerConstraintSystem)
1115            .unwrap();
1116        let cf_r1cs = extract_r1cs::<Fq>(&cs2);
1117
1118        let (pedersen_params, _) =
1119            Pedersen::<Projective>::setup(&mut rng, ccs.n - ccs.l - 1).unwrap();
1120        let (cf_pedersen_params, _) =
1121            Pedersen::<Projective2>::setup(&mut rng, cf_r1cs.A.n_cols - cf_r1cs.l - 1).unwrap();
1122
1123        // public params hash
1124        let pp_hash = Fr::from(42u32); // only for test
1125
1126        // first step
1127        let z_0 = vec![Fr::from(3_u32)];
1128        let mut z_i = z_0.clone();
1129
1130        // prepare the dummy instances
1131        let W_dummy = Witness::<Fr>::dummy(&ccs);
1132        let U_dummy = LCCCS::<Projective>::dummy(ccs.l, ccs.t, ccs.s);
1133        let w_dummy = W_dummy.clone();
1134        let u_dummy = CCCS::<Projective>::dummy(ccs.l);
1135        let (cf_W_dummy, cf_U_dummy): (NovaWitness<Projective2>, CommittedInstance<Projective2>) =
1136            cf_r1cs.dummy_instance();
1137
1138        // set the initial dummy instances
1139        let mut W_i = W_dummy.clone();
1140        let mut U_i = U_dummy.clone();
1141        let mut w_i = w_dummy.clone();
1142        let mut u_i = u_dummy.clone();
1143        let mut cf_W_i = cf_W_dummy.clone();
1144        let mut cf_U_i = cf_U_dummy.clone();
1145        u_i.x = vec![
1146            U_i.hash(&sponge, pp_hash, Fr::zero(), z_0.clone(), z_i.clone()),
1147            cf_U_i.hash_cyclefold(&sponge, pp_hash),
1148        ];
1149
1150        let n_steps: usize = 4;
1151        let mut iFr = Fr::zero();
1152        for i in 0..n_steps {
1153            let start = Instant::now();
1154
1155            let z_i1 = F_circuit.step_native(i, z_i.clone(), vec![]).unwrap();
1156
1157            let (U_i1, W_i1);
1158
1159            if i == 0 {
1160                W_i1 = Witness::<Fr>::dummy(&ccs);
1161                U_i1 = LCCCS::dummy(ccs.l, ccs.t, ccs.s);
1162
1163                let u_i1_x = U_i1.hash(&sponge, pp_hash, Fr::one(), z_0.clone(), z_i1.clone());
1164
1165                // hash the initial (dummy) CycleFold instance, which is used as the 2nd public
1166                // input in the AugmentedFCircuit
1167                let cf_u_i1_x = cf_U_i.hash_cyclefold(&sponge, pp_hash);
1168
1169                augmented_f_circuit =
1170                    AugmentedFCircuit::<Projective, Projective2, GVar2, CubicFCircuit<Fr>> {
1171                        _c2: PhantomData,
1172                        _gc2: PhantomData,
1173                        poseidon_config: poseidon_config.clone(),
1174                        ccs: ccs.clone(),
1175                        pp_hash: Some(pp_hash),
1176                        i: Some(Fr::zero()),
1177                        i_usize: Some(0),
1178                        z_0: Some(z_0.clone()),
1179                        z_i: Some(z_i.clone()),
1180                        external_inputs: Some(vec![]),
1181                        u_i_C: Some(u_i.C),
1182                        U_i: Some(U_i.clone()),
1183                        U_i1_C: Some(U_i1.C),
1184                        F: F_circuit,
1185                        x: Some(u_i1_x),
1186                        nimfs_proof: None,
1187
1188                        // cyclefold values
1189                        cf_u_i_cmW: None,
1190                        cf_U_i: None,
1191                        cf_x: Some(cf_u_i1_x),
1192                        cf_cmT: None,
1193                    };
1194            } else {
1195                let mut transcript_p: PoseidonSponge<Fr> =
1196                    PoseidonSponge::<Fr>::new(&poseidon_config.clone());
1197                transcript_p.absorb(&pp_hash);
1198                let (rho_bits, nimfs_proof);
1199                (nimfs_proof, U_i1, W_i1, rho_bits) =
1200                    NIMFS::<Projective, PoseidonSponge<Fr>>::prove(
1201                        &mut transcript_p,
1202                        &ccs,
1203                        &[U_i.clone()],
1204                        &[u_i.clone()],
1205                        &[W_i.clone()],
1206                        &[w_i.clone()],
1207                    )
1208                    .unwrap();
1209
1210                // sanity check: check the folded instance relation
1211                U_i1.check_relation(&ccs, &W_i1).unwrap();
1212
1213                let u_i1_x =
1214                    U_i1.hash(&sponge, pp_hash, iFr + Fr::one(), z_0.clone(), z_i1.clone());
1215
1216                let rho_Fq = Fq::from_bigint(BigInteger::from_bits_le(&rho_bits)).unwrap();
1217                // CycleFold part:
1218                // get the vector used as public inputs 'x' in the CycleFold circuit
1219                // cyclefold circuit for cmW
1220                let cf_u_i_x = [
1221                    vec![rho_Fq],
1222                    get_cm_coordinates(&U_i.C),
1223                    get_cm_coordinates(&u_i.C),
1224                    get_cm_coordinates(&U_i1.C),
1225                ]
1226                .concat();
1227
1228                let cf_circuit = CycleFoldCircuit::<Projective, GVar> {
1229                    _gc: PhantomData,
1230                    r_bits: Some(rho_bits.clone()),
1231                    p1: Some(U_i.clone().C),
1232                    p2: Some(u_i.clone().C),
1233                    x: Some(cf_u_i_x.clone()),
1234                };
1235
1236                let (_cf_w_i, cf_u_i, cf_W_i1, cf_U_i1, cf_cmT, _) = fold_cyclefold_circuit::<
1237                    Projective,
1238                    GVar,
1239                    Projective2,
1240                    GVar2,
1241                    CubicFCircuit<Fr>,
1242                    Pedersen<Projective>,
1243                    Pedersen<Projective2>,
1244                >(
1245                    &mut transcript_p,
1246                    cf_r1cs.clone(),
1247                    cf_pedersen_params.clone(),
1248                    pp_hash,
1249                    cf_W_i.clone(), // CycleFold running instance witness
1250                    cf_U_i.clone(), // CycleFold running instance
1251                    cf_u_i_x,       // CycleFold incoming instance
1252                    cf_circuit,
1253                )
1254                .unwrap();
1255
1256                // hash the CycleFold folded instance, which is used as the 2nd public input in the
1257                // AugmentedFCircuit
1258                let cf_u_i1_x = cf_U_i1.hash_cyclefold(&sponge, pp_hash);
1259
1260                augmented_f_circuit =
1261                    AugmentedFCircuit::<Projective, Projective2, GVar2, CubicFCircuit<Fr>> {
1262                        _c2: PhantomData,
1263                        _gc2: PhantomData,
1264                        poseidon_config: poseidon_config.clone(),
1265                        ccs: ccs.clone(),
1266                        pp_hash: Some(pp_hash),
1267                        i: Some(iFr),
1268                        i_usize: Some(i),
1269                        z_0: Some(z_0.clone()),
1270                        z_i: Some(z_i.clone()),
1271                        external_inputs: Some(vec![]),
1272                        u_i_C: Some(u_i.C),
1273                        U_i: Some(U_i.clone()),
1274                        U_i1_C: Some(U_i1.C),
1275                        F: F_circuit,
1276                        x: Some(u_i1_x),
1277                        nimfs_proof: Some(nimfs_proof),
1278
1279                        // cyclefold values
1280                        cf_u_i_cmW: Some(cf_u_i.cmW),
1281                        cf_U_i: Some(cf_U_i),
1282                        cf_x: Some(cf_u_i1_x),
1283                        cf_cmT: Some(cf_cmT),
1284                    };
1285
1286                // assign the next round instances
1287                cf_W_i = cf_W_i1;
1288                cf_U_i = cf_U_i1;
1289            }
1290
1291            let (cs, _) = augmented_f_circuit.compute_cs_ccs().unwrap();
1292            assert!(cs.is_satisfied().unwrap());
1293
1294            let (r1cs_w_i1, r1cs_x_i1) = extract_w_x::<Fr>(&cs); // includes 1 and public inputs
1295            assert_eq!(r1cs_x_i1[0], augmented_f_circuit.x.unwrap());
1296            let r1cs_z = [vec![Fr::one()], r1cs_x_i1.clone(), r1cs_w_i1.clone()].concat();
1297            // compute committed instances, w_{i+1}, u_{i+1}, which will be used as w_i, u_i, so we
1298            // assign them directly to w_i, u_i.
1299            (u_i, w_i) = ccs
1300                .to_cccs::<_, _, Pedersen<Projective>>(&mut rng, &pedersen_params, &r1cs_z)
1301                .unwrap();
1302            u_i.check_relation(&ccs, &w_i).unwrap();
1303
1304            // sanity checks
1305            assert_eq!(w_i.w, r1cs_w_i1);
1306            assert_eq!(u_i.x, r1cs_x_i1);
1307            assert_eq!(u_i.x[0], augmented_f_circuit.x.unwrap());
1308            assert_eq!(u_i.x[1], augmented_f_circuit.cf_x.unwrap());
1309            let expected_u_i1_x =
1310                U_i1.hash(&sponge, pp_hash, iFr + Fr::one(), z_0.clone(), z_i1.clone());
1311            let expected_cf_U_i1_x = cf_U_i.hash_cyclefold(&sponge, pp_hash);
1312            // u_i is already u_i1 at this point, check that has the expected value at x[0]
1313            assert_eq!(u_i.x[0], expected_u_i1_x);
1314            assert_eq!(u_i.x[1], expected_cf_U_i1_x);
1315
1316            // set values for next iteration
1317            iFr += Fr::one();
1318            // assign z_{i+1} into z_i
1319            z_i = z_i1.clone();
1320            U_i = U_i1.clone();
1321            W_i = W_i1.clone();
1322
1323            // check the new LCCCS instance relation
1324            U_i.check_relation(&ccs, &W_i).unwrap();
1325            // check the new CCCS instance relation
1326            u_i.check_relation(&ccs, &w_i).unwrap();
1327
1328            // check the CycleFold instance relation
1329            cf_r1cs
1330                .check_relaxed_instance_relation(&cf_W_i, &cf_U_i)
1331                .unwrap();
1332
1333            println!("augmented_f_circuit step {}: {:?}", i, start.elapsed());
1334        }
1335    }
1336}