Struct curve25519_dalek::edwards::ExtendedPoint

pub struct ExtendedPoint { /* fields omitted */ }

An ExtendedPoint represents a point on the Edwards form of Curve25519.

The name refers to the extended twisted Edwards coordinates of Hisil, Wong, Carter, and Dawson, and more details on curve models can be found in the curve25519-dalek internal documentation.

Methods

impl ExtendedPoint

fn to_montgomery(&self) -> MontgomeryPoint

Convert this ExtendedPoint on the Edwards model to the corresponding MontgomeryPoint on the Montgomery model.

Note that this is a one-way conversion, since the Montgomery model does not retain sign information.

fn compress(&self) -> CompressedEdwardsY

Compress this point to CompressedEdwardsY format.

impl ExtendedPoint

fn mult_by_cofactor(&self) -> ExtendedPoint

Multiply by the cofactor: compute 8 * self.

fn is_small_order(&self) -> bool

Determine if this point is of small order.

The order of the group of points on the curve \(\mathcal E\) is \(|\mathcal E| = 8\ell \), so its structure is \( \mathcal E = \mathcal E[8] \times \mathcal E[\ell]\). The torsion subgroup \( \mathcal E[8] \) consists of eight points of small order. (Technically all of \(\mathcal E\) is torsion, but we use the word only to refer to the \(\mathcal E[8]\) part, not the prime-order subgroup \(\mathcal E[\ell]\).

For more information on cofactors and the group structure, see the internal curve25519-dalek documentation on Ristretto.

Return

True if self is of small order; false otherwise.

Trait Implementations

impl Copy for ExtendedPoint

impl Clone for ExtendedPoint

fn clone(&self) -> ExtendedPoint

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Identity for ExtendedPoint

fn identity() -> ExtendedPoint

Returns the identity element of the curve. Can be used as a constructor.

impl ConditionallyAssignable for ExtendedPoint

fn conditional_assign(&mut self, other: &ExtendedPoint, choice: u8)

Conditionally assign other to self in constant time.

impl Equal for ExtendedPoint

fn ct_eq(&self, other: &ExtendedPoint) -> u8

Determine if two items are equal in constant time.

impl<'a, 'b> Add<&'b ExtendedPoint> for &'a ExtendedPoint

type Output = ExtendedPoint

The resulting type after applying the + operator.

fn add(self, other: &'b ExtendedPoint) -> ExtendedPoint

Performs the + operation.

impl<'b> Add<&'b ExtendedPoint> for ExtendedPoint

type Output = ExtendedPoint

The resulting type after applying the + operator.

fn add(self, rhs: &'b ExtendedPoint) -> ExtendedPoint

Performs the + operation.

impl<'a> Add<ExtendedPoint> for &'a ExtendedPoint

type Output = ExtendedPoint

The resulting type after applying the + operator.

fn add(self, rhs: ExtendedPoint) -> ExtendedPoint

Performs the + operation.

impl Add<ExtendedPoint> for ExtendedPoint

type Output = ExtendedPoint

The resulting type after applying the + operator.

fn add(self, rhs: ExtendedPoint) -> ExtendedPoint

Performs the + operation.

impl<'b> AddAssign<&'b ExtendedPoint> for ExtendedPoint

fn add_assign(&mut self, _rhs: &'b ExtendedPoint)

Performs the += operation.

impl AddAssign<ExtendedPoint> for ExtendedPoint

fn add_assign(&mut self, rhs: ExtendedPoint)

Performs the += operation.

impl<'a, 'b> Sub<&'b ExtendedPoint> for &'a ExtendedPoint

type Output = ExtendedPoint

The resulting type after applying the - operator.

fn sub(self, other: &'b ExtendedPoint) -> ExtendedPoint

Performs the - operation.

impl<'b> Sub<&'b ExtendedPoint> for ExtendedPoint

type Output = ExtendedPoint

The resulting type after applying the - operator.

fn sub(self, rhs: &'b ExtendedPoint) -> ExtendedPoint

Performs the - operation.

impl<'a> Sub<ExtendedPoint> for &'a ExtendedPoint

type Output = ExtendedPoint

The resulting type after applying the - operator.

fn sub(self, rhs: ExtendedPoint) -> ExtendedPoint

Performs the - operation.

impl Sub<ExtendedPoint> for ExtendedPoint

type Output = ExtendedPoint

The resulting type after applying the - operator.

fn sub(self, rhs: ExtendedPoint) -> ExtendedPoint

Performs the - operation.

impl<'b> SubAssign<&'b ExtendedPoint> for ExtendedPoint

fn sub_assign(&mut self, _rhs: &'b ExtendedPoint)

Performs the -= operation.

impl SubAssign<ExtendedPoint> for ExtendedPoint

fn sub_assign(&mut self, rhs: ExtendedPoint)

Performs the -= operation.

impl<'a> Neg for &'a ExtendedPoint

type Output = ExtendedPoint

The resulting type after applying the - operator.

fn neg(self) -> ExtendedPoint

Performs the unary - operation.

impl Neg for ExtendedPoint

type Output = ExtendedPoint

The resulting type after applying the - operator.

fn neg(self) -> ExtendedPoint

Performs the unary - operation.

impl<'b> MulAssign<&'b Scalar> for ExtendedPoint

fn mul_assign(&mut self, scalar: &'b Scalar)

Performs the *= operation.

impl MulAssign<Scalar> for ExtendedPoint

fn mul_assign(&mut self, rhs: Scalar)

Performs the *= operation.

impl<'b> Mul<&'b Scalar> for ExtendedPoint

type Output = ExtendedPoint

The resulting type after applying the * operator.

fn mul(self, rhs: &'b Scalar) -> ExtendedPoint

Performs the * operation.

impl<'a> Mul<Scalar> for &'a ExtendedPoint

type Output = ExtendedPoint

The resulting type after applying the * operator.

fn mul(self, rhs: Scalar) -> ExtendedPoint

Performs the * operation.

impl Mul<Scalar> for ExtendedPoint

type Output = ExtendedPoint

The resulting type after applying the * operator.

fn mul(self, rhs: Scalar) -> ExtendedPoint

Performs the * operation.

impl<'a, 'b> Mul<&'b Scalar> for &'a ExtendedPoint

type Output = ExtendedPoint

The resulting type after applying the * operator.

fn mul(self, scalar: &'b Scalar) -> ExtendedPoint

Scalar multiplication: compute scalar * self.

For scalar multiplication of a basepoint, EdwardsBasepointTable is approximately 4x faster.

impl Debug for ExtendedPoint

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<'a, 'b> Add<&'b ProjectiveNielsPoint> for &'a ExtendedPoint

type Output = CompletedPoint

The resulting type after applying the + operator.

fn add(self, other: &'b ProjectiveNielsPoint) -> CompletedPoint

Performs the + operation.

impl<'a, 'b> Sub<&'b ProjectiveNielsPoint> for &'a ExtendedPoint

type Output = CompletedPoint

The resulting type after applying the - operator.

fn sub(self, other: &'b ProjectiveNielsPoint) -> CompletedPoint

Performs the - operation.

impl<'a, 'b> Add<&'b AffineNielsPoint> for &'a ExtendedPoint

type Output = CompletedPoint

The resulting type after applying the + operator.

fn add(self, other: &'b AffineNielsPoint) -> CompletedPoint

Performs the + operation.

impl<'a, 'b> Sub<&'b AffineNielsPoint> for &'a ExtendedPoint

type Output = CompletedPoint

The resulting type after applying the - operator.

fn sub(self, other: &'b AffineNielsPoint) -> CompletedPoint

Performs the - operation.