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143 | @dataclass(frozen=True)
class WhirVerifier(
VerifierStage[
OpeningClaim[WhirCommitment],
TrivialClaim,
OpeningProof[WhirProof],
Transcript,
]
):
"""WHIR PCS verifier. `code`/`tree`/`params`/`scheme` must
match the prover's."""
code: ReedSolomon
tree: StridedMerkleTree
params: WhirParams
scheme: WhirScheme = EqWhirScheme()
def verify(
self,
claim: OpeningClaim[WhirCommitment],
reduction_proof: OpeningProof[WhirProof],
transcript: TranscriptT,
) -> VerifyResult[TrivialClaim, TranscriptT]:
"""Check the claimed evaluations against the commitment."""
ok, transcript = self._verify_opening(
claim.commitment,
claim.points,
reduction_proof.values,
reduction_proof.proof,
transcript,
)
return VerifyResult(TrivialClaim(), transcript, ok)
def _verify_opening(
self,
commitment: WhirCommitment,
points: Sequence[Array],
values: Array,
proof: WhirProof,
transcript: TranscriptT,
) -> tuple[Array, TranscriptT]:
"""Return `(ok, transcript)` where `ok` is a scalar boolean array."""
if len(points) != 1:
raise ValueError(f"WHIR opens at one point, got {len(points)}")
z = points[0]
m = z.shape[0]
k = self.params.k_whir
num_rounds = len(self.params.num_queries)
if not (0 < num_rounds * k <= m):
raise ValueError(
f"num_rounds·k_whir ({num_rounds}·{k}) must fold between 1 and "
f"num_variables ({m}) inclusive"
)
# Fail loud on a structurally malformed proof — a short list would let the
# round loop silently skip checks (mirrors BasefoldVerifier.verify_batch).
lengths = {
"sumcheck_polys": (len(proof.sumcheck_polys), num_rounds * k),
"folding_pow_witnesses": (len(proof.folding_pow_witnesses), num_rounds * k),
"query_pow_witnesses": (len(proof.query_pow_witnesses), num_rounds),
"codeword_roots": (len(proof.codeword_roots), num_rounds - 1),
"ood_values": (len(proof.ood_values), num_rounds - 1),
"codeword_openings": (len(proof.codeword_openings), num_rounds - 1),
}
bad = {
name: got_exp
for name, got_exp in lengths.items()
if got_exp[0] != got_exp[1]
}
if bad:
raise ValueError(f"malformed WHIR proof: {bad} (got, expected)")
# This verifier checks a single commitment (one tree); a multi-commitment
# proof is a prover-side capability its consumer byte-matches without
# round-tripping here, so reject it loudly rather than silently
# under-verifying openings 1..n.
if len(proof.initial_openings) != 1:
raise ValueError(
"this verifier checks a single commitment, got "
f"{len(proof.initial_openings)} initial openings"
)
num_polys = proof.initial_openings[0].row.shape[-1]
if values.ndim != 1 or values.shape[0] != num_polys:
raise ValueError(
f"values must be 1-D of length num_polys ({num_polys}), got shape "
f"{values.shape}"
)
# `final_poly` carries the 2^(m − num_rounds·k) residual coefficients in
# the clear (one coefficient at full fold); a wrong length would surface
# only as a cryptic shape error inside the jitted body.
r_dim = m - num_rounds * k
if proof.final_poly.ndim != 1 or proof.final_poly.shape[0] != (1 << r_dim):
raise ValueError(
f"final_poly must be 1-D of length 2^{r_dim} ({1 << r_dim}), got "
f"shape {proof.final_poly.shape}"
)
return _verify_body(self, commitment, z, values, proof, transcript)
|