arnaucube
arnaucube/NovaPublic Self-hosted repository
Nova/src/spartan/mod.rs
src/spartan/mod.rsRaw
  1//! This module implements RelaxedR1CSSNARKTrait using Spartan that is generic
  2//! over the polynomial commitment and evaluation argument (i.e., a PCS)
  3mod math;
  4pub(crate) mod polynomial;
  5pub mod pp;
  6mod sumcheck;
  7
  8use crate::{
  9  compute_digest,
 10  errors::NovaError,
 11  r1cs::{R1CSShape, RelaxedR1CSInstance, RelaxedR1CSWitness},
 12  traits::{
 13    evaluation::EvaluationEngineTrait, snark::RelaxedR1CSSNARKTrait, Group, TranscriptEngineTrait,
 14  },
 15  Commitment, CommitmentKey,
 16};
 17use ff::Field;
 18use itertools::concat;
 19use polynomial::{EqPolynomial, MultilinearPolynomial, SparsePolynomial};
 20use rayon::prelude::*;
 21use serde::{Deserialize, Serialize};
 22use sumcheck::SumcheckProof;
 23
 24fn powers<G: Group>(s: &G::Scalar, n: usize) -> Vec<G::Scalar> {
 25  assert!(n >= 1);
 26  let mut powers = Vec::new();
 27  powers.push(G::Scalar::ONE);
 28  for i in 1..n {
 29    powers.push(powers[i - 1] * s);
 30  }
 31  powers
 32}
 33
 34/// A type that holds a witness to a polynomial evaluation instance
 35pub struct PolyEvalWitness<G: Group> {
 36  p: Vec<G::Scalar>, // polynomial
 37}
 38
 39impl<G: Group> PolyEvalWitness<G> {
 40  fn pad(W: &[PolyEvalWitness<G>]) -> Vec<PolyEvalWitness<G>> {
 41    // determine the maximum size
 42    if let Some(n) = W.iter().map(|w| w.p.len()).max() {
 43      W.iter()
 44        .map(|w| {
 45          let mut p = w.p.clone();
 46          p.resize(n, G::Scalar::ZERO);
 47          PolyEvalWitness { p }
 48        })
 49        .collect()
 50    } else {
 51      Vec::new()
 52    }
 53  }
 54
 55  fn weighted_sum(W: &[PolyEvalWitness<G>], s: &[G::Scalar]) -> PolyEvalWitness<G> {
 56    assert_eq!(W.len(), s.len());
 57    let mut p = vec![G::Scalar::ZERO; W[0].p.len()];
 58    for i in 0..W.len() {
 59      for j in 0..W[i].p.len() {
 60        p[j] += W[i].p[j] * s[i]
 61      }
 62    }
 63    PolyEvalWitness { p }
 64  }
 65
 66  fn batch(p_vec: &[&Vec<G::Scalar>], s: &G::Scalar) -> PolyEvalWitness<G> {
 67    let powers_of_s = powers::<G>(s, p_vec.len());
 68    let mut p = vec![G::Scalar::ZERO; p_vec[0].len()];
 69    for i in 0..p_vec.len() {
 70      for (j, item) in p.iter_mut().enumerate().take(p_vec[i].len()) {
 71        *item += p_vec[i][j] * powers_of_s[i]
 72      }
 73    }
 74    PolyEvalWitness { p }
 75  }
 76}
 77
 78/// A type that holds a polynomial evaluation instance
 79pub struct PolyEvalInstance<G: Group> {
 80  c: Commitment<G>,  // commitment to the polynomial
 81  x: Vec<G::Scalar>, // evaluation point
 82  e: G::Scalar,      // claimed evaluation
 83}
 84
 85impl<G: Group> PolyEvalInstance<G> {
 86  fn pad(U: &[PolyEvalInstance<G>]) -> Vec<PolyEvalInstance<G>> {
 87    // determine the maximum size
 88    if let Some(ell) = U.iter().map(|u| u.x.len()).max() {
 89      U.iter()
 90        .map(|u| {
 91          let mut x = vec![G::Scalar::ZERO; ell - u.x.len()];
 92          x.extend(u.x.clone());
 93          PolyEvalInstance { c: u.c, x, e: u.e }
 94        })
 95        .collect()
 96    } else {
 97      Vec::new()
 98    }
 99  }
100
101  fn batch(
102    c_vec: &[Commitment<G>],
103    x: &[G::Scalar],
104    e_vec: &[G::Scalar],
105    s: &G::Scalar,
106  ) -> PolyEvalInstance<G> {
107    let powers_of_s = powers::<G>(s, c_vec.len());
108    let e = e_vec
109      .iter()
110      .zip(powers_of_s.iter())
111      .map(|(e, p)| *e * p)
112      .sum();
113    let c = c_vec
114      .iter()
115      .zip(powers_of_s.iter())
116      .map(|(c, p)| *c * *p)
117      .fold(Commitment::<G>::default(), |acc, item| acc + item);
118
119    PolyEvalInstance {
120      c,
121      x: x.to_vec(),
122      e,
123    }
124  }
125}
126
127/// A type that represents the prover's key
128#[derive(Serialize, Deserialize)]
129#[serde(bound = "")]
130pub struct ProverKey<G: Group, EE: EvaluationEngineTrait<G, CE = G::CE>> {
131  pk_ee: EE::ProverKey,
132  S: R1CSShape<G>,
133  vk_digest: G::Scalar, // digest of the verifier's key
134}
135
136/// A type that represents the verifier's key
137#[derive(Serialize, Deserialize)]
138#[serde(bound = "")]
139pub struct VerifierKey<G: Group, EE: EvaluationEngineTrait<G, CE = G::CE>> {
140  vk_ee: EE::VerifierKey,
141  S: R1CSShape<G>,
142  digest: G::Scalar,
143}
144
145/// A succinct proof of knowledge of a witness to a relaxed R1CS instance
146/// The proof is produced using Spartan's combination of the sum-check and
147/// the commitment to a vector viewed as a polynomial commitment
148#[derive(Serialize, Deserialize)]
149#[serde(bound = "")]
150pub struct RelaxedR1CSSNARK<G: Group, EE: EvaluationEngineTrait<G, CE = G::CE>> {
151  sc_proof_outer: SumcheckProof<G>,
152  claims_outer: (G::Scalar, G::Scalar, G::Scalar),
153  eval_E: G::Scalar,
154  sc_proof_inner: SumcheckProof<G>,
155  eval_W: G::Scalar,
156  sc_proof_batch: SumcheckProof<G>,
157  evals_batch: Vec<G::Scalar>,
158  eval_arg: EE::EvaluationArgument,
159}
160
161impl<G: Group, EE: EvaluationEngineTrait<G, CE = G::CE>> RelaxedR1CSSNARKTrait<G>
162  for RelaxedR1CSSNARK<G, EE>
163{
164  type ProverKey = ProverKey<G, EE>;
165  type VerifierKey = VerifierKey<G, EE>;
166
167  fn setup(
168    ck: &CommitmentKey<G>,
169    S: &R1CSShape<G>,
170  ) -> Result<(Self::ProverKey, Self::VerifierKey), NovaError> {
171    let (pk_ee, vk_ee) = EE::setup(ck);
172
173    let S = S.pad();
174
175    let vk = {
176      let mut vk = VerifierKey {
177        vk_ee,
178        S: S.clone(),
179        digest: G::Scalar::ZERO,
180      };
181      vk.digest = compute_digest::<G, VerifierKey<G, EE>>(&vk);
182      vk
183    };
184
185    let pk = ProverKey {
186      pk_ee,
187      S,
188      vk_digest: vk.digest,
189    };
190
191    Ok((pk, vk))
192  }
193
194  /// produces a succinct proof of satisfiability of a RelaxedR1CS instance
195  fn prove(
196    ck: &CommitmentKey<G>,
197    pk: &Self::ProverKey,
198    U: &RelaxedR1CSInstance<G>,
199    W: &RelaxedR1CSWitness<G>,
200  ) -> Result<Self, NovaError> {
201    let W = W.pad(&pk.S); // pad the witness
202    let mut transcript = G::TE::new(b"RelaxedR1CSSNARK");
203
204    // sanity check that R1CSShape has certain size characteristics
205    assert_eq!(pk.S.num_cons.next_power_of_two(), pk.S.num_cons);
206    assert_eq!(pk.S.num_vars.next_power_of_two(), pk.S.num_vars);
207    assert_eq!(pk.S.num_io.next_power_of_two(), pk.S.num_io);
208    assert!(pk.S.num_io < pk.S.num_vars);
209
210    // append the digest of vk (which includes R1CS matrices) and the RelaxedR1CSInstance to the transcript
211    transcript.absorb(b"vk", &pk.vk_digest);
212    transcript.absorb(b"U", U);
213
214    // compute the full satisfying assignment by concatenating W.W, U.u, and U.X
215    let mut z = concat(vec![W.W.clone(), vec![U.u], U.X.clone()]);
216
217    let (num_rounds_x, num_rounds_y) = (
218      (pk.S.num_cons as f64).log2() as usize,
219      ((pk.S.num_vars as f64).log2() as usize + 1),
220    );
221
222    // outer sum-check
223    let tau = (0..num_rounds_x)
224      .map(|_i| transcript.squeeze(b"t"))
225      .collect::<Result<Vec<G::Scalar>, NovaError>>()?;
226
227    let mut poly_tau = MultilinearPolynomial::new(EqPolynomial::new(tau).evals());
228    let (mut poly_Az, mut poly_Bz, poly_Cz, mut poly_uCz_E) = {
229      let (poly_Az, poly_Bz, poly_Cz) = pk.S.multiply_vec(&z)?;
230      let poly_uCz_E = (0..pk.S.num_cons)
231        .map(|i| U.u * poly_Cz[i] + W.E[i])
232        .collect::<Vec<G::Scalar>>();
233      (
234        MultilinearPolynomial::new(poly_Az),
235        MultilinearPolynomial::new(poly_Bz),
236        MultilinearPolynomial::new(poly_Cz),
237        MultilinearPolynomial::new(poly_uCz_E),
238      )
239    };
240
241    let comb_func_outer =
242      |poly_A_comp: &G::Scalar,
243       poly_B_comp: &G::Scalar,
244       poly_C_comp: &G::Scalar,
245       poly_D_comp: &G::Scalar|
246       -> G::Scalar { *poly_A_comp * (*poly_B_comp * *poly_C_comp - *poly_D_comp) };
247    let (sc_proof_outer, r_x, claims_outer) = SumcheckProof::prove_cubic_with_additive_term(
248      &G::Scalar::ZERO, // claim is zero
249      num_rounds_x,
250      &mut poly_tau,
251      &mut poly_Az,
252      &mut poly_Bz,
253      &mut poly_uCz_E,
254      comb_func_outer,
255      &mut transcript,
256    )?;
257
258    // claims from the end of sum-check
259    let (claim_Az, claim_Bz): (G::Scalar, G::Scalar) = (claims_outer[1], claims_outer[2]);
260    let claim_Cz = poly_Cz.evaluate(&r_x);
261    let eval_E = MultilinearPolynomial::new(W.E.clone()).evaluate(&r_x);
262    transcript.absorb(
263      b"claims_outer",
264      &[claim_Az, claim_Bz, claim_Cz, eval_E].as_slice(),
265    );
266
267    // inner sum-check
268    let r = transcript.squeeze(b"r")?;
269    let claim_inner_joint = claim_Az + r * claim_Bz + r * r * claim_Cz;
270
271    let poly_ABC = {
272      // compute the initial evaluation table for R(\tau, x)
273      let evals_rx = EqPolynomial::new(r_x.clone()).evals();
274
275      // Bounds "row" variables of (A, B, C) matrices viewed as 2d multilinear polynomials
276      let compute_eval_table_sparse =
277        |S: &R1CSShape<G>, rx: &[G::Scalar]| -> (Vec<G::Scalar>, Vec<G::Scalar>, Vec<G::Scalar>) {
278          assert_eq!(rx.len(), S.num_cons);
279
280          let inner = |M: &Vec<(usize, usize, G::Scalar)>, M_evals: &mut Vec<G::Scalar>| {
281            for (row, col, val) in M {
282              M_evals[*col] += rx[*row] * val;
283            }
284          };
285
286          let (A_evals, (B_evals, C_evals)) = rayon::join(
287            || {
288              let mut A_evals: Vec<G::Scalar> = vec![G::Scalar::ZERO; 2 * S.num_vars];
289              inner(&S.A, &mut A_evals);
290              A_evals
291            },
292            || {
293              rayon::join(
294                || {
295                  let mut B_evals: Vec<G::Scalar> = vec![G::Scalar::ZERO; 2 * S.num_vars];
296                  inner(&S.B, &mut B_evals);
297                  B_evals
298                },
299                || {
300                  let mut C_evals: Vec<G::Scalar> = vec![G::Scalar::ZERO; 2 * S.num_vars];
301                  inner(&S.C, &mut C_evals);
302                  C_evals
303                },
304              )
305            },
306          );
307
308          (A_evals, B_evals, C_evals)
309        };
310
311      let (evals_A, evals_B, evals_C) = compute_eval_table_sparse(&pk.S, &evals_rx);
312
313      assert_eq!(evals_A.len(), evals_B.len());
314      assert_eq!(evals_A.len(), evals_C.len());
315      (0..evals_A.len())
316        .into_par_iter()
317        .map(|i| evals_A[i] + r * evals_B[i] + r * r * evals_C[i])
318        .collect::<Vec<G::Scalar>>()
319    };
320
321    let poly_z = {
322      z.resize(pk.S.num_vars * 2, G::Scalar::ZERO);
323      z
324    };
325
326    let comb_func = |poly_A_comp: &G::Scalar, poly_B_comp: &G::Scalar| -> G::Scalar {
327      *poly_A_comp * *poly_B_comp
328    };
329    let (sc_proof_inner, r_y, _claims_inner) = SumcheckProof::prove_quad(
330      &claim_inner_joint,
331      num_rounds_y,
332      &mut MultilinearPolynomial::new(poly_ABC),
333      &mut MultilinearPolynomial::new(poly_z),
334      comb_func,
335      &mut transcript,
336    )?;
337
338    // add additional claims about W and E polynomials to the list from CC
339    let mut w_u_vec = Vec::new();
340    let eval_W = MultilinearPolynomial::evaluate_with(&W.W, &r_y[1..]);
341    w_u_vec.push((
342      PolyEvalWitness { p: W.W.clone() },
343      PolyEvalInstance {
344        c: U.comm_W,
345        x: r_y[1..].to_vec(),
346        e: eval_W,
347      },
348    ));
349
350    w_u_vec.push((
351      PolyEvalWitness { p: W.E },
352      PolyEvalInstance {
353        c: U.comm_E,
354        x: r_x,
355        e: eval_E,
356      },
357    ));
358
359    // We will now reduce a vector of claims of evaluations at different points into claims about them at the same point.
360    // For example, eval_W =? W(r_y[1..]) and eval_W =? E(r_x) into
361    // two claims: eval_W_prime =? W(rz) and eval_E_prime =? E(rz)
362    // We can them combine the two into one: eval_W_prime + gamma * eval_E_prime =? (W + gamma*E)(rz),
363    // where gamma is a public challenge
364    // Since commitments to W and E are homomorphic, the verifier can compute a commitment
365    // to the batched polynomial.
366    assert!(w_u_vec.len() >= 2);
367
368    let (w_vec, u_vec): (Vec<PolyEvalWitness<G>>, Vec<PolyEvalInstance<G>>) =
369      w_u_vec.into_iter().unzip();
370    let w_vec_padded = PolyEvalWitness::pad(&w_vec); // pad the polynomials to be of the same size
371    let u_vec_padded = PolyEvalInstance::pad(&u_vec); // pad the evaluation points
372
373    // generate a challenge
374    let rho = transcript.squeeze(b"r")?;
375    let num_claims = w_vec_padded.len();
376    let powers_of_rho = powers::<G>(&rho, num_claims);
377    let claim_batch_joint = u_vec_padded
378      .iter()
379      .zip(powers_of_rho.iter())
380      .map(|(u, p)| u.e * p)
381      .sum();
382
383    let mut polys_left: Vec<MultilinearPolynomial<G::Scalar>> = w_vec_padded
384      .iter()
385      .map(|w| MultilinearPolynomial::new(w.p.clone()))
386      .collect();
387    let mut polys_right: Vec<MultilinearPolynomial<G::Scalar>> = u_vec_padded
388      .iter()
389      .map(|u| MultilinearPolynomial::new(EqPolynomial::new(u.x.clone()).evals()))
390      .collect();
391
392    let num_rounds_z = u_vec_padded[0].x.len();
393    let comb_func = |poly_A_comp: &G::Scalar, poly_B_comp: &G::Scalar| -> G::Scalar {
394      *poly_A_comp * *poly_B_comp
395    };
396    let (sc_proof_batch, r_z, claims_batch) = SumcheckProof::prove_quad_batch(
397      &claim_batch_joint,
398      num_rounds_z,
399      &mut polys_left,
400      &mut polys_right,
401      &powers_of_rho,
402      comb_func,
403      &mut transcript,
404    )?;
405
406    let (claims_batch_left, _): (Vec<G::Scalar>, Vec<G::Scalar>) = claims_batch;
407
408    transcript.absorb(b"l", &claims_batch_left.as_slice());
409
410    // we now combine evaluation claims at the same point rz into one
411    let gamma = transcript.squeeze(b"g")?;
412    let powers_of_gamma: Vec<G::Scalar> = powers::<G>(&gamma, num_claims);
413    let comm_joint = u_vec_padded
414      .iter()
415      .zip(powers_of_gamma.iter())
416      .map(|(u, g_i)| u.c * *g_i)
417      .fold(Commitment::<G>::default(), |acc, item| acc + item);
418    let poly_joint = PolyEvalWitness::weighted_sum(&w_vec_padded, &powers_of_gamma);
419    let eval_joint = claims_batch_left
420      .iter()
421      .zip(powers_of_gamma.iter())
422      .map(|(e, g_i)| *e * *g_i)
423      .sum();
424
425    let eval_arg = EE::prove(
426      ck,
427      &pk.pk_ee,
428      &mut transcript,
429      &comm_joint,
430      &poly_joint.p,
431      &r_z,
432      &eval_joint,
433    )?;
434
435    Ok(RelaxedR1CSSNARK {
436      sc_proof_outer,
437      claims_outer: (claim_Az, claim_Bz, claim_Cz),
438      eval_E,
439      sc_proof_inner,
440      eval_W,
441      sc_proof_batch,
442      evals_batch: claims_batch_left,
443      eval_arg,
444    })
445  }
446
447  /// verifies a proof of satisfiability of a RelaxedR1CS instance
448  fn verify(&self, vk: &Self::VerifierKey, U: &RelaxedR1CSInstance<G>) -> Result<(), NovaError> {
449    let mut transcript = G::TE::new(b"RelaxedR1CSSNARK");
450
451    // append the digest of R1CS matrices and the RelaxedR1CSInstance to the transcript
452    transcript.absorb(b"vk", &vk.digest);
453    transcript.absorb(b"U", U);
454
455    let (num_rounds_x, num_rounds_y) = (
456      (vk.S.num_cons as f64).log2() as usize,
457      ((vk.S.num_vars as f64).log2() as usize + 1),
458    );
459
460    // outer sum-check
461    let tau = (0..num_rounds_x)
462      .map(|_i| transcript.squeeze(b"t"))
463      .collect::<Result<Vec<G::Scalar>, NovaError>>()?;
464
465    let (claim_outer_final, r_x) =
466      self
467        .sc_proof_outer
468        .verify(G::Scalar::ZERO, num_rounds_x, 3, &mut transcript)?;
469
470    // verify claim_outer_final
471    let (claim_Az, claim_Bz, claim_Cz) = self.claims_outer;
472    let taus_bound_rx = EqPolynomial::new(tau).evaluate(&r_x);
473    let claim_outer_final_expected =
474      taus_bound_rx * (claim_Az * claim_Bz - U.u * claim_Cz - self.eval_E);
475    if claim_outer_final != claim_outer_final_expected {
476      return Err(NovaError::InvalidSumcheckProof);
477    }
478
479    transcript.absorb(
480      b"claims_outer",
481      &[
482        self.claims_outer.0,
483        self.claims_outer.1,
484        self.claims_outer.2,
485        self.eval_E,
486      ]
487      .as_slice(),
488    );
489
490    // inner sum-check
491    let r = transcript.squeeze(b"r")?;
492    let claim_inner_joint =
493      self.claims_outer.0 + r * self.claims_outer.1 + r * r * self.claims_outer.2;
494
495    let (claim_inner_final, r_y) =
496      self
497        .sc_proof_inner
498        .verify(claim_inner_joint, num_rounds_y, 2, &mut transcript)?;
499
500    // verify claim_inner_final
501    let eval_Z = {
502      let eval_X = {
503        // constant term
504        let mut poly_X = vec![(0, U.u)];
505        //remaining inputs
506        poly_X.extend(
507          (0..U.X.len())
508            .map(|i| (i + 1, U.X[i]))
509            .collect::<Vec<(usize, G::Scalar)>>(),
510        );
511        SparsePolynomial::new((vk.S.num_vars as f64).log2() as usize, poly_X).evaluate(&r_y[1..])
512      };
513      (G::Scalar::ONE - r_y[0]) * self.eval_W + r_y[0] * eval_X
514    };
515
516    // compute evaluations of R1CS matrices
517    let multi_evaluate = |M_vec: &[&[(usize, usize, G::Scalar)]],
518                          r_x: &[G::Scalar],
519                          r_y: &[G::Scalar]|
520     -> Vec<G::Scalar> {
521      let evaluate_with_table =
522        |M: &[(usize, usize, G::Scalar)], T_x: &[G::Scalar], T_y: &[G::Scalar]| -> G::Scalar {
523          (0..M.len())
524            .collect::<Vec<usize>>()
525            .par_iter()
526            .map(|&i| {
527              let (row, col, val) = M[i];
528              T_x[row] * T_y[col] * val
529            })
530            .reduce(|| G::Scalar::ZERO, |acc, x| acc + x)
531        };
532
533      let (T_x, T_y) = rayon::join(
534        || EqPolynomial::new(r_x.to_vec()).evals(),
535        || EqPolynomial::new(r_y.to_vec()).evals(),
536      );
537
538      (0..M_vec.len())
539        .collect::<Vec<usize>>()
540        .par_iter()
541        .map(|&i| evaluate_with_table(M_vec[i], &T_x, &T_y))
542        .collect()
543    };
544
545    let evals = multi_evaluate(&[&vk.S.A, &vk.S.B, &vk.S.C], &r_x, &r_y);
546
547    let claim_inner_final_expected = (evals[0] + r * evals[1] + r * r * evals[2]) * eval_Z;
548    if claim_inner_final != claim_inner_final_expected {
549      return Err(NovaError::InvalidSumcheckProof);
550    }
551
552    // add claims about W and E polynomials
553    let u_vec: Vec<PolyEvalInstance<G>> = vec![
554      PolyEvalInstance {
555        c: U.comm_W,
556        x: r_y[1..].to_vec(),
557        e: self.eval_W,
558      },
559      PolyEvalInstance {
560        c: U.comm_E,
561        x: r_x,
562        e: self.eval_E,
563      },
564    ];
565
566    let u_vec_padded = PolyEvalInstance::pad(&u_vec); // pad the evaluation points
567
568    // generate a challenge
569    let rho = transcript.squeeze(b"r")?;
570    let num_claims = u_vec.len();
571    let powers_of_rho = powers::<G>(&rho, num_claims);
572    let claim_batch_joint = u_vec
573      .iter()
574      .zip(powers_of_rho.iter())
575      .map(|(u, p)| u.e * p)
576      .sum();
577
578    let num_rounds_z = u_vec_padded[0].x.len();
579    let (claim_batch_final, r_z) =
580      self
581        .sc_proof_batch
582        .verify(claim_batch_joint, num_rounds_z, 2, &mut transcript)?;
583
584    let claim_batch_final_expected = {
585      let poly_rz = EqPolynomial::new(r_z.clone());
586      let evals = u_vec_padded
587        .iter()
588        .map(|u| poly_rz.evaluate(&u.x))
589        .collect::<Vec<G::Scalar>>();
590
591      evals
592        .iter()
593        .zip(self.evals_batch.iter())
594        .zip(powers_of_rho.iter())
595        .map(|((e_i, p_i), rho_i)| *e_i * *p_i * rho_i)
596        .sum()
597    };
598
599    if claim_batch_final != claim_batch_final_expected {
600      return Err(NovaError::InvalidSumcheckProof);
601    }
602
603    transcript.absorb(b"l", &self.evals_batch.as_slice());
604
605    // we now combine evaluation claims at the same point rz into one
606    let gamma = transcript.squeeze(b"g")?;
607    let powers_of_gamma: Vec<G::Scalar> = powers::<G>(&gamma, num_claims);
608    let comm_joint = u_vec_padded
609      .iter()
610      .zip(powers_of_gamma.iter())
611      .map(|(u, g_i)| u.c * *g_i)
612      .fold(Commitment::<G>::default(), |acc, item| acc + item);
613    let eval_joint = self
614      .evals_batch
615      .iter()
616      .zip(powers_of_gamma.iter())
617      .map(|(e, g_i)| *e * *g_i)
618      .sum();
619
620    // verify
621    EE::verify(
622      &vk.vk_ee,
623      &mut transcript,
624      &comm_joint,
625      &r_z,
626      &eval_joint,
627      &self.eval_arg,
628    )?;
629
630    Ok(())
631  }
632}