consensus-specs/tests/formats/kzg_4844/verify_kzg_proof.md

Test format: Verify KZG proof

Verify the KZG proof for a given blob and an evaluation point z that claims to result in a value of y.

Test case format

The test data is declared in a data.yaml file:

input:
  commitment: KZGCommitment -- the KZG commitment to the data blob
  z: Bytes32 -- bytes encoding the BLS field element at which the polynomial should be evaluated
  y: Bytes32 -- the claimed result of the evaluation
  proof: KZGProof -- The KZG proof
output: bool -- true (valid proof) or false (incorrect proof)

• z here is encoded as a string: hexadecimal encoding of 32 bytes representing a big endian encoded field element, prefixed with 0x.
• y here is encoded as a string: hexadecimal encoding of 32 bytes representing a big endian encoded field element, prefixed with 0x.

All byte(s) fields are encoded as strings, hexadecimal encoding, prefixed with 0x.

Condition

The verify_kzg_proof handler should verify the KZG proof for evaluating the polynomial represented by blob at z resulting in the value y, and the result should match the expected output. If the commitment or proof is invalid (e.g. not on the curve or not in the G1 subgroup of the BLS curve) or z or y are not a valid BLS field element, it should error, i.e. the output should be null.