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surge.rs
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surge.rs
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#![allow(clippy::type_complexity)]
#![allow(clippy::too_many_arguments)]
#![allow(clippy::needless_range_loop)]
use crate::lasso::densified::DensifiedRepresentation;
use crate::lasso::memory_checking::MemoryCheckingProof;
use crate::poly::dense_mlpoly::{DensePolynomial, PolyCommitment, PolyCommitmentGens};
use crate::poly::eq_poly::EqPolynomial;
use crate::subprotocols::sumcheck::SumcheckInstanceProof;
use crate::subtables::{
CombinedTableCommitment, CombinedTableEvalProof, SubtableStrategy, Subtables,
};
use crate::utils::errors::ProofVerifyError;
use crate::utils::math::Math;
use crate::utils::random::RandomTape;
use crate::utils::transcript::{AppendToTranscript, ProofTranscript};
use ark_ec::CurveGroup;
use ark_serialize::*;
use ark_std::log2;
use merlin::Transcript;
use std::marker::Sync;
pub struct SparsePolyCommitmentGens<G> {
pub gens_combined_l_variate: PolyCommitmentGens<G>,
pub gens_combined_log_m_variate: PolyCommitmentGens<G>,
pub gens_derefs: PolyCommitmentGens<G>,
}
impl<G: CurveGroup> SparsePolyCommitmentGens<G> {
pub fn new(
label: &'static [u8],
c: usize,
s: usize,
num_memories: usize,
log_m: usize,
) -> SparsePolyCommitmentGens<G> {
// dim_1, ... dim_c, read_1, ..., read_c
// log_2(cs + cs)
let num_vars_combined_l_variate = (2 * c * s).next_power_of_two().log_2();
// final
// log_2(cm) = log_2(c) + log_2(m)
let num_vars_combined_log_m_variate = c.next_power_of_two().log_2() + log_m;
// E_1, ..., E_alpha
// log_2(alpha * s)
let num_vars_derefs = (num_memories * s).next_power_of_two().log_2();
let gens_combined_l_variate = PolyCommitmentGens::new(num_vars_combined_l_variate, label);
let gens_combined_log_m_variate =
PolyCommitmentGens::new(num_vars_combined_log_m_variate, label);
let gens_derefs = PolyCommitmentGens::new(num_vars_derefs, label);
SparsePolyCommitmentGens {
gens_combined_l_variate,
gens_combined_log_m_variate,
gens_derefs,
}
}
}
#[derive(Debug, CanonicalSerialize, CanonicalDeserialize)]
pub struct SparsePolynomialCommitment<G: CurveGroup> {
pub l_variate_polys_commitment: PolyCommitment<G>,
pub log_m_variate_polys_commitment: PolyCommitment<G>,
pub s: usize, // sparsity
pub log_m: usize,
pub m: usize,
}
impl<G: CurveGroup> AppendToTranscript<G> for SparsePolynomialCommitment<G> {
fn append_to_transcript<T: ProofTranscript<G>>(&self, _label: &'static [u8], transcript: &mut T) {
self
.l_variate_polys_commitment
.append_to_transcript(b"l_variate_polys_commitment", transcript);
self
.log_m_variate_polys_commitment
.append_to_transcript(b"log_m_variate_polys_commitment", transcript);
transcript.append_u64(b"s", self.s as u64);
transcript.append_u64(b"log_m", self.log_m as u64);
transcript.append_u64(b"m", self.m as u64);
}
}
#[derive(Debug, CanonicalSerialize, CanonicalDeserialize)]
struct PrimarySumcheck<G: CurveGroup, const ALPHA: usize> {
proof: SumcheckInstanceProof<G::ScalarField>,
claimed_evaluation: G::ScalarField,
eval_derefs: [G::ScalarField; ALPHA],
proof_derefs: CombinedTableEvalProof<G, ALPHA>,
}
#[derive(Debug, CanonicalSerialize, CanonicalDeserialize)]
pub struct SparsePolynomialEvaluationProof<
G: CurveGroup,
const C: usize,
const M: usize,
S: SubtableStrategy<G::ScalarField, C, M> + Sync,
> where
[(); S::NUM_MEMORIES]: Sized,
{
comm_derefs: CombinedTableCommitment<G>,
primary_sumcheck: PrimarySumcheck<G, { S::NUM_MEMORIES }>,
memory_check: MemoryCheckingProof<G, C, M, S>,
}
impl<G: CurveGroup, const C: usize, const M: usize, S: SubtableStrategy<G::ScalarField, C, M> + Sync>
SparsePolynomialEvaluationProof<G, C, M, S>
where
[(); S::NUM_SUBTABLES]: Sized,
[(); S::NUM_MEMORIES]: Sized,
[(); S::NUM_MEMORIES + 1]: Sized,
{
/// Prove an opening of the Sparse Matrix Polynomial
/// - `dense`: DensifiedRepresentation
/// - `r`: log(s) sized coordinates at which to prove the evaluation of eq in the primary sumcheck
/// - `eval`: evaluation of \widetilde{M}(r = (r_1, ..., r_logM))
/// - `gens`: Commitment generator
#[tracing::instrument(skip_all, name = "SparsePoly.prove")]
pub fn prove(
dense: &mut DensifiedRepresentation<G::ScalarField, C>,
r: &Vec<G::ScalarField>,
gens: &SparsePolyCommitmentGens<G>,
transcript: &mut Transcript,
random_tape: &mut RandomTape<G>,
) -> Self
where
[(); S::NUM_SUBTABLES]: Sized,
{
<Transcript as ProofTranscript<G>>::append_protocol_name(transcript, Self::protocol_name());
assert_eq!(r.len(), log2(dense.s) as usize);
let subtables = Subtables::<_, C, M, S>::new(&dense.dim_usize, dense.s);
// commit to non-deterministic choices of the prover
let comm_derefs = {
let comm = subtables.commit(&gens.gens_derefs);
comm.append_to_transcript(b"comm_poly_row_col_ops_val", transcript);
comm
};
let eq = EqPolynomial::new(r.clone());
let claimed_eval = subtables.compute_sumcheck_claim(&eq);
<Transcript as ProofTranscript<G>>::append_scalar(
transcript,
b"claim_eval_scalar_product",
&claimed_eval,
);
let mut combined_sumcheck_polys: [DensePolynomial<G::ScalarField>; S::NUM_MEMORIES + 1] =
std::array::from_fn(|i| {
if i != S::NUM_MEMORIES {
subtables.lookup_polys[i].clone()
} else {
DensePolynomial::new(eq.evals())
}
});
let (primary_sumcheck_proof, r_z, _) = SumcheckInstanceProof::<G::ScalarField>::prove_arbitrary::<
_,
G,
Transcript,
{ S::NUM_MEMORIES + 1 },
>(
&claimed_eval,
dense.s.log_2(),
&mut combined_sumcheck_polys,
S::combine_lookups_eq,
S::sumcheck_poly_degree(),
transcript,
);
// Combined eval proof for E_i(r_z)
let eval_derefs: [G::ScalarField; S::NUM_MEMORIES] =
std::array::from_fn(|i| subtables.lookup_polys[i].evaluate(&r_z));
let proof_derefs = CombinedTableEvalProof::prove(
&subtables.combined_poly,
eval_derefs.as_ref(),
&r_z,
&gens.gens_derefs,
transcript,
random_tape,
);
let memory_check = {
// produce a random element from the transcript for hash function
let r_hash_params: Vec<G::ScalarField> =
<Transcript as ProofTranscript<G>>::challenge_vector(transcript, b"challenge_r_hash", 2);
MemoryCheckingProof::prove(
dense,
&(r_hash_params[0], r_hash_params[1]),
&subtables,
gens,
transcript,
random_tape,
)
};
Self {
comm_derefs,
primary_sumcheck: PrimarySumcheck {
proof: primary_sumcheck_proof,
claimed_evaluation: claimed_eval,
eval_derefs,
proof_derefs,
},
memory_check,
}
}
#[tracing::instrument(skip_all, name = "SparsePoly.verify")]
pub fn verify(
&self,
commitment: &SparsePolynomialCommitment<G>,
eq_randomness: &Vec<G::ScalarField>,
gens: &SparsePolyCommitmentGens<G>,
transcript: &mut Transcript,
) -> Result<(), ProofVerifyError> {
<Transcript as ProofTranscript<G>>::append_protocol_name(transcript, Self::protocol_name());
debug_assert_eq!(eq_randomness.len(), log2(commitment.s) as usize);
// add claims to transcript and obtain challenges for randomized mem-check circuit
self
.comm_derefs
.append_to_transcript(b"comm_poly_row_col_ops_val", transcript);
<Transcript as ProofTranscript<G>>::append_scalar(
transcript,
b"claim_eval_scalar_product",
&self.primary_sumcheck.claimed_evaluation,
);
let (claim_last, r_z) = self.primary_sumcheck.proof.verify::<G, Transcript>(
self.primary_sumcheck.claimed_evaluation,
commitment.s.log_2(),
S::sumcheck_poly_degree(),
transcript,
)?;
// Verify that eq(r, r_z) * g(E_1(r_z) * ... * E_c(r_z)) = claim_last
let eq_eval = EqPolynomial::new(eq_randomness.clone()).evaluate(&r_z);
assert_eq!(
eq_eval * S::combine_lookups(&self.primary_sumcheck.eval_derefs),
claim_last,
"Primary sumcheck check failed."
);
self.primary_sumcheck.proof_derefs.verify(
&r_z,
&self.primary_sumcheck.eval_derefs,
&gens.gens_derefs,
&self.comm_derefs,
transcript,
)?;
// produce a random element from the transcript for hash function
let r_mem_check =
<Transcript as ProofTranscript<G>>::challenge_vector(transcript, b"challenge_r_hash", 2);
self.memory_check.verify(
commitment,
&self.comm_derefs,
gens,
&(r_mem_check[0], r_mem_check[1]),
commitment.s,
transcript,
)
}
fn protocol_name() -> &'static [u8] {
b"Lasso SparsePolynomialEvaluationProof"
}
}