Struct elastic_elgamal::group::Curve25519Subgroup
source · pub struct Curve25519Subgroup(/* private fields */);
Expand description
Prime-order subgroup of Curve25519 without any transforms performed for EC points.
Since the curve has cofactor 8, ElementOps::deserialize_element()
implementation
explicitly checks on deserializing each EC point that the point is torsion-free
(belongs to the prime-order subgroup), which is moderately slow (takes ~0.1ms on
a laptop).
Prefer using Ristretto
if compatibility with other Curve25519 applications is not a concern.
(If it is a concern, beware of cofactor pitfalls!)
Trait Implementations§
source§impl Clone for Curve25519Subgroup
impl Clone for Curve25519Subgroup
source§fn clone(&self) -> Curve25519Subgroup
fn clone(&self) -> Curve25519Subgroup
Returns a copy of the value. Read more
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from
source
. Read moresource§impl Debug for Curve25519Subgroup
impl Debug for Curve25519Subgroup
source§impl ElementOps for Curve25519Subgroup
impl ElementOps for Curve25519Subgroup
§type Element = EdwardsPoint
type Element = EdwardsPoint
Element of the group. Arithmetic operations requested here (addition among
elements and multiplication by a
Scalar
) must be constant-time.source§const ELEMENT_SIZE: usize = 32usize
const ELEMENT_SIZE: usize = 32usize
Byte size of a serialized
Self::Element
.source§fn identity() -> Self::Element
fn identity() -> Self::Element
Returns the identity of the group (aka point at infinity for EC groups).
source§fn is_identity(element: &Self::Element) -> bool
fn is_identity(element: &Self::Element) -> bool
Checks if the specified element is the identity.
source§fn serialize_element(element: &Self::Element, buffer: &mut [u8])
fn serialize_element(element: &Self::Element, buffer: &mut [u8])
source§fn deserialize_element(buffer: &[u8]) -> Option<Self::Element>
fn deserialize_element(buffer: &[u8]) -> Option<Self::Element>
Deserializes an element from
buffer
, which is guaranteed to have length
Self::ELEMENT_SIZE
. This method returns None
if the buffer
does not correspond to a representation of a valid scalar.source§impl Group for Curve25519Subgroup
impl Group for Curve25519Subgroup
source§fn mul_generator(k: &Scalar) -> Self::Element
fn mul_generator(k: &Scalar) -> Self::Element
Multiplies the provided scalar by
ElementOps::generator()
. This operation must be
constant-time. Read moresource§fn vartime_mul_generator(k: &Scalar) -> Self::Element
fn vartime_mul_generator(k: &Scalar) -> Self::Element
Multiplies the provided scalar by
ElementOps::generator()
.
Unlike Self::mul_generator()
, this operation does not need to be constant-time;
thus, it may employ additional optimizations. Read moresource§fn multi_mul<'a, I, J>(scalars: I, elements: J) -> Self::Element
fn multi_mul<'a, I, J>(scalars: I, elements: J) -> Self::Element
Multiplies provided
scalars
by elements
. This operation must be constant-time
w.r.t. the given length of elements. Read moresource§fn vartime_double_mul_generator(
k: &Scalar,
k_element: Self::Element,
r: &Scalar
) -> Self::Element
fn vartime_double_mul_generator( k: &Scalar, k_element: Self::Element, r: &Scalar ) -> Self::Element
Calculates
k * k_element + r * G
, where G
is the group generator. This operation
does not need to be constant-time. Read moresource§fn vartime_multi_mul<'a, I, J>(scalars: I, elements: J) -> Self::Element
fn vartime_multi_mul<'a, I, J>(scalars: I, elements: J) -> Self::Element
Multiplies provided
scalars
by elements
. Unlike Self::multi_mul()
,
this operation does not need to be constant-time; thus, it may employ
additional optimizations. Read moresource§impl Hash for Curve25519Subgroup
impl Hash for Curve25519Subgroup
source§impl PartialEq for Curve25519Subgroup
impl PartialEq for Curve25519Subgroup
source§fn eq(&self, other: &Curve25519Subgroup) -> bool
fn eq(&self, other: &Curve25519Subgroup) -> bool
This method tests for
self
and other
values to be equal, and is used
by ==
.source§impl ScalarOps for Curve25519Subgroup
impl ScalarOps for Curve25519Subgroup
§type Scalar = Scalar
type Scalar = Scalar
Scalar type. As per
Group
contract, scalars must form a prime field.
Arithmetic operations on scalars requested here must be constant-time.source§const SCALAR_SIZE: usize = 32usize
const SCALAR_SIZE: usize = 32usize
Byte size of a serialized
Self::Scalar
.source§fn generate_scalar<R: CryptoRng + RngCore>(rng: &mut R) -> Self::Scalar
fn generate_scalar<R: CryptoRng + RngCore>(rng: &mut R) -> Self::Scalar
Generates a random scalar based on the provided CSPRNG. This operation
must be constant-time.
source§fn scalar_from_random_bytes(source: RandomBytesProvider<'_>) -> Self::Scalar
fn scalar_from_random_bytes(source: RandomBytesProvider<'_>) -> Self::Scalar
Generates a scalar from a
source
of random bytes. This operation must be constant-time.
The source
is guaranteed to return any necessary number of bytes. Read moresource§fn invert_scalar(scalar: Self::Scalar) -> Self::Scalar
fn invert_scalar(scalar: Self::Scalar) -> Self::Scalar
Inverts the
scalar
, which is guaranteed to be non-zero. This operation does not
need to be constant-time.source§fn invert_scalars(scalars: &mut [Self::Scalar])
fn invert_scalars(scalars: &mut [Self::Scalar])
Inverts scalars in a batch. This operation does not need to be constant-time. Read more
source§fn serialize_scalar(scalar: &Self::Scalar, buffer: &mut [u8])
fn serialize_scalar(scalar: &Self::Scalar, buffer: &mut [u8])
Serializes the scalar into the provided
buffer
, which is guaranteed to have length
Self::SCALAR_SIZE
.source§fn deserialize_scalar(buffer: &[u8]) -> Option<Self::Scalar>
fn deserialize_scalar(buffer: &[u8]) -> Option<Self::Scalar>
Deserializes the scalar from
buffer
, which is guaranteed to have length
Self::SCALAR_SIZE
. This method returns None
if the buffer
does not correspond to a representation of a valid scalar.impl Copy for Curve25519Subgroup
impl Eq for Curve25519Subgroup
impl StructuralPartialEq for Curve25519Subgroup
Auto Trait Implementations§
impl Freeze for Curve25519Subgroup
impl RefUnwindSafe for Curve25519Subgroup
impl Send for Curve25519Subgroup
impl Sync for Curve25519Subgroup
impl Unpin for Curve25519Subgroup
impl UnwindSafe for Curve25519Subgroup
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more