Trait ark_ec::models::twisted_edwards::TECurveConfig

pub trait TECurveConfig: CurveConfig {
    type MontCurveConfig: MontCurveConfig<BaseField = Self::BaseField>;

    const COEFF_A: Self::BaseField;
    const COEFF_D: Self::BaseField;
    const GENERATOR: Affine<Self>;

    fn mul_by_a(elem: Self::BaseField) -> Self::BaseField { ... }
    fn is_in_correct_subgroup_assuming_on_curve(item: &Affine<Self>) -> bool { ... }
    fn clear_cofactor(item: &Affine<Self>) -> Affine<Self> { ... }
    fn mul_projective(
        base: &Projective<Self>,
        scalar: &[u64]
    ) -> Projective<Self> { ... }
    fn mul_affine(base: &Affine<Self>, scalar: &[u64]) -> Projective<Self> { ... }
    fn msm(
        bases: &[Affine<Self>],
        scalars: &[Self::ScalarField]
    ) -> Result<Projective<Self>, usize> { ... }
    fn serialize_with_mode<W: Write>(
        item: &Affine<Self>,
        writer: W,
        compress: Compress
    ) -> Result<(), SerializationError> { ... }
    fn deserialize_with_mode<R: Read>(
        reader: R,
        compress: Compress,
        validate: Validate
    ) -> Result<Affine<Self>, SerializationError> { ... }
    fn serialized_size(compress: Compress) -> usize { ... }
}

Constants and convenience functions that collectively define the Twisted Edwards model of the curve. In this model, the curve equation is a * x² + y² = 1 + d * x² * y², for constants a and d.

Required Associated Types

type MontCurveConfig: MontCurveConfig<BaseField = Self::BaseField>

Model parameters for the Montgomery curve that is birationally equivalent to this curve.

Required Associated Constants

const COEFF_A: Self::BaseField

Coefficient a of the curve equation.

const COEFF_D: Self::BaseField

Coefficient d of the curve equation.

const GENERATOR: Affine<Self>

Generator of the prime-order subgroup.

Provided Methods

fn mul_by_a(elem: Self::BaseField) -> Self::BaseField

Helper method for computing elem * Self::COEFF_A.

The default implementation should be overridden only if the product can be computed faster than standard field multiplication (eg: via doubling if COEFF_A == 2, or if COEFF_A.is_zero()).

fn is_in_correct_subgroup_assuming_on_curve(item: &Affine<Self>) -> bool

Checks that the current point is in the prime order subgroup given the point on the curve.

fn clear_cofactor(item: &Affine<Self>) -> Affine<Self>

Performs cofactor clearing. The default method is simply to multiply by the cofactor. For some curve families though, it is sufficient to multiply by a smaller scalar.

fn mul_projective(base: &Projective<Self>, scalar: &[u64]) -> Projective<Self>

Default implementation of group multiplication for projective coordinates

fn mul_affine(base: &Affine<Self>, scalar: &[u64]) -> Projective<Self>

Default implementation of group multiplication for affine coordinates

fn msm(
    bases: &[Affine<Self>],
    scalars: &[Self::ScalarField]
) -> Result<Projective<Self>, usize>

Default implementation for multi scalar multiplication

fn serialize_with_mode<W: Write>(
    item: &Affine<Self>,
    writer: W,
    compress: Compress
) -> Result<(), SerializationError>

If uncompressed, serializes both x and y coordinates. If compressed, serializes y coordinate with a bit to encode whether x is positive.

fn deserialize_with_mode<R: Read>(
    reader: R,
    compress: Compress,
    validate: Validate
) -> Result<Affine<Self>, SerializationError>

If validate is Yes, calls check() to make sure the element is valid.

Uses Affine::get_xs_from_y_unchecked() for the compressed version.

fn serialized_size(compress: Compress) -> usize

Implementors