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Brakedown+++ (#46)
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* conversion to `into_iter` is a no-op

* remove explicit casts to vecs

* rename to use singular of `labeled_commitment`

* simplify the iterators even further by zipping two iters

* Apply suggestions from code review
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@mmagician
mmagician authored Nov 14, 2023
1 parent b00defd commit 2b403fd
Showing 1 changed file with 17 additions and 42 deletions.
59 changes: 17 additions & 42 deletions poly-commit/src/linear_codes/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -236,7 +236,7 @@ where
let mut commitments = Vec::new();
let mut states = Vec::new();

for labeled_polynomial in polynomials.into_iter() {
for labeled_polynomial in polynomials {
let polynomial = labeled_polynomial.polynomial();

// 1. Arrange the coefficients of the polynomial into a matrix,
Expand Down Expand Up @@ -299,7 +299,7 @@ where

fn open<'a>(
ck: &Self::CommitterKey,
labeled_polynomials: impl IntoIterator<Item = &'a LabeledPolynomial<F, P>>,
_labeled_polynomials: impl IntoIterator<Item = &'a LabeledPolynomial<F, P>>,
commitments: impl IntoIterator<Item = &'a LabeledCommitment<Self::Commitment>>,
point: &'a P::Point,
_challenge_generator: &mut crate::challenge::ChallengeGenerator<F, S>,
Expand All @@ -312,22 +312,9 @@ where
Self::Commitment: 'a,
{
let mut proof_array = LPCPArray::default();
let labeled_commitments: Vec<&'a LabeledCommitment<Self::Commitment>> =
commitments.into_iter().collect();
let labeled_polynomials: Vec<&'a LabeledPolynomial<F, P>> =
labeled_polynomials.into_iter().collect();
let states: Vec<&'a Self::CommitmentState> = states.into_iter().collect();

if labeled_commitments.len() != labeled_polynomials.len() {
return Err(Error::IncorrectInputLength(format!(
"Mismatched lengths: {} commitments, {} polynomials",
labeled_commitments.len(),
labeled_polynomials.len()
)));
}

for i in 0..labeled_polynomials.len() {
let commitment = labeled_commitments[i].commitment();
for (labeled_commitment, state) in commitments.into_iter().zip(states) {
let commitment = labeled_commitment.commitment();
let n_rows = commitment.metadata.n_rows;
let n_cols = commitment.metadata.n_cols;
let root = &commitment.root;
Expand All @@ -339,7 +326,7 @@ where
mat,
ext_mat,
leaves: col_hashes,
} = states[i];
} = state;
let mut col_hashes: Vec<C::Leaf> =
col_hashes.clone().into_iter().map(|h| h.into()).collect();

Expand Down Expand Up @@ -414,25 +401,13 @@ where
where
Self::Commitment: 'a,
{
let labeled_commitments: Vec<&'a LabeledCommitment<Self::Commitment>> =
commitments.into_iter().collect();
let values: Vec<F> = values.into_iter().collect();

if labeled_commitments.len() != proof_array.len()
|| labeled_commitments.len() != values.len()
{
return Err(Error::IncorrectInputLength(
format!(
"Mismatched lengths: {} proofs were provided for {} commitments with {} claimed values",labeled_commitments.len(), proof_array.len(), values.len()
)
));
}
let leaf_hash_param: &<<C as Config>::LeafHash as CRHScheme>::Parameters =
vk.leaf_hash_param();
let two_to_one_hash_param: &<<C as Config>::TwoToOneHash as TwoToOneCRHScheme>::Parameters =
vk.two_to_one_hash_param();

for (i, labeled_commitment) in labeled_commitments.iter().enumerate() {
for (i, (labeled_commitment, value)) in commitments.into_iter().zip(values).enumerate() {
let proof = &proof_array[i];
let commitment = labeled_commitment.commitment();
let n_rows = commitment.metadata.n_rows;
let n_cols = commitment.metadata.n_cols;
Expand All @@ -446,10 +421,10 @@ where
.map_err(|_| Error::TranscriptError)?;

let out = if vk.check_well_formedness() {
if proof_array[i].well_formedness.is_none() {
if proof.well_formedness.is_none() {
return Err(Error::InvalidCommitment);
}
let tmp = &proof_array[i].well_formedness.as_ref();
let tmp = &proof.well_formedness.as_ref();
let well_formedness = tmp.unwrap();
let mut r = Vec::with_capacity(n_rows);
for _ in 0..n_rows {
Expand Down Expand Up @@ -478,14 +453,14 @@ where
.map_err(|_| Error::TranscriptError)?;
}
transcript
.append_serializable_element(b"v", &proof_array[i].opening.v)
.append_serializable_element(b"v", &proof.opening.v)
.map_err(|_| Error::TranscriptError)?;

// 2. Ask random oracle for the `t` indices where the checks happen.
let indices = get_indices_from_transcript::<F>(n_ext_cols, t, &mut transcript)?;

// 3. Hash the received columns into leaf hashes.
let col_hashes: Vec<C::Leaf> = proof_array[i]
let col_hashes: Vec<C::Leaf> = proof
.opening
.columns
.iter()
Expand All @@ -501,7 +476,7 @@ where
// even if we have a well-formedness check (i.e., we save sending and checking the columns).
// See "Concrete optimizations to the commitment scheme", p.12 of [Brakedown](https://eprint.iacr.org/2021/1043.pdf).
for (j, (leaf, q_j)) in col_hashes.iter().zip(indices.iter()).enumerate() {
let path = &proof_array[i].opening.paths[j];
let path = &proof.opening.paths[j];
if path.leaf_index != *q_j {
return Err(Error::InvalidCommitment);
}
Expand All @@ -520,7 +495,7 @@ where
};

// 5. Compute the encoding w = E(v).
let w = L::encode(&proof_array[i].opening.v, vk)?;
let w = L::encode(&proof.opening.v, vk)?;

// 6. Compute `a`, `b` to right- and left- multiply with the matrix `M`.
let (a, b) = L::tensor(point, n_cols, n_rows);
Expand All @@ -533,26 +508,26 @@ where
for (transcript_index, matrix_index) in indices.iter().enumerate() {
check_inner_product(
&r,
&proof_array[i].opening.columns[transcript_index],
&proof.opening.columns[transcript_index],
w_well_formedness[*matrix_index],
)?;
check_inner_product(
&b,
&proof_array[i].opening.columns[transcript_index],
&proof.opening.columns[transcript_index],
w[*matrix_index],
)?;
}
} else {
for (transcript_index, matrix_index) in indices.iter().enumerate() {
check_inner_product(
&b,
&proof_array[i].opening.columns[transcript_index],
&proof.opening.columns[transcript_index],
w[*matrix_index],
)?;
}
}

if inner_product(&proof_array[i].opening.v, &a) != values[i] {
if inner_product(&proof.opening.v, &a) != value {
eprintln!("Function check: claimed value in position {i} does not match the evaluation of the committed polynomial in the same position");
return Ok(false);
}
Expand Down

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