Interface PolynomialCommitment

poly-commit/src/lib.rs:164–577

Describes the interface for a polynomial commitment scheme that allows a sender to commit to multiple polynomials and later provide a succinct proof of evaluation for the corresponding commitments at a query set `Q`, while enforcing per-polynomial degree bounds.

/// of evaluation for the corresponding commitments at a query set `Q`, while
/// enforcing per-polynomial degree bounds.
pub trait PolynomialCommitment<F: PrimeField, P: Polynomial<F>>: Sized {
    /// The universal parameters for the commitment scheme. These are "trimmed"
    /// down to `Self::CommitterKey` and `Self::VerifierKey` by `Self::trim`.
    type UniversalParams: PCUniversalParams;
    /// The committer key for the scheme; used to commit to a polynomial and then
    /// open the commitment to produce an evaluation proof.
    type CommitterKey: PCCommitterKey;
    /// The verifier key for the scheme; used to check an evaluation proof.
    type VerifierKey: PCVerifierKey;
    /// The commitment to a polynomial.
    type Commitment: PCCommitment + Default;
    /// Auxiliary state of the commitment, output by the `commit` phase.
    /// It contains information that can be reused by the committer
    /// during the `open` phase, such as the commitment randomness.
    /// Not to be shared with the verifier.
    type CommitmentState: PCCommitmentState;
    /// The evaluation proof for a single point.
    type Proof: Clone;
    /// The evaluation proof for a query set.
    type BatchProof: Clone
        + From<Vec<Self::Proof>>
        + Into<Vec<Self::Proof>>
        + CanonicalSerialize
        + CanonicalDeserialize;
    /// The error type for the scheme.
    type Error: ark_std::error::Error + From<Error>;

    /// Constructs public parameters when given as input the maximum degree `degree`
    /// for the polynomial commitment scheme. `num_vars` specifies the number of
    /// variables for multivariate setup
    fn setup<R: RngCore>(
        max_degree: usize,
        num_vars: Option<usize>,
        rng: &mut R,
    ) -> Result<Self::UniversalParams, Self::Error>;

    /// Specializes the public parameters for polynomials up to the given `supported_degree`
    /// and for enforcing degree bounds in the range `1..=supported_degree`.
    fn trim(
        pp: &Self::UniversalParams,
        supported_degree: usize,
        supported_hiding_bound: usize,
        enforced_degree_bounds: Option<&[usize]>,
    ) -> Result<(Self::CommitterKey, Self::VerifierKey), Self::Error>;

    /// Outputs a list of commitments to `polynomials`. If `polynomials[i].is_hiding()`,
    /// then the `i`-th commitment is hiding up to `polynomials.hiding_bound()` queries.
    /// `rng` should not be `None` if `polynomials[i].is_hiding() == true` for any `i`.
    ///
    /// If for some `i`, `polynomials[i].is_hiding() == false`, then the
    /// corresponding randomness is `Self::Randomness::empty()`.
    ///
    /// If for some `i`, `polynomials[i].degree_bound().is_some()`, then that
    /// polynomial will have the corresponding degree bound enforced.
    fn commit<'a>(
        ck: &Self::CommitterKey,
        polynomials: impl IntoIterator<Item = &'a LabeledPolynomial<F, P>>,
        rng: Option<&mut dyn RngCore>,