eth2.0-specs/tests/formats/kzg/compute_kzg_proof.md

Test format: Compute KZG proof

Compute the KZG proof for a given blob and an evaluation point z.

Test case format

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

input:
  blob: Blob -- the data blob representing a polynomial
  z: Bytes32 -- bytes encoding the BLS field element at which the polynomial should be evaluated
output: Tuple[KZGProof, Bytes32] -- The KZG proof and the value y = f(z)

• blob here is encoded as a string: hexadecimal encoding of 4096 * 32 = 131072 bytes, prefixed with 0x.
• 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 compute_kzg_proof handler should compute the KZG proof as well as the value y for evaluating the polynomial represented by blob at z, and the result should match the expected output. If the blob is invalid (e.g. incorrect length or one of the 32-byte blocks does not represent a BLS field element) or z is not a valid BLS field element, it should error, i.e. the output should be null.