Struct FieldElement51 

pub struct FieldElement51(/* private fields */);

Available on curve25519_dalek_bits=64 and docsrs only.

A FieldElement51 represents an element of the field \( \mathbb Z / (2^{255} - 19)\).

In the 64-bit implementation, a FieldElement is represented in radix \(2^{51}\) as five u64s; the coefficients are allowed to grow up to \(2^{54}\) between reductions modulo \(p\).

Note

The curve25519_dalek::field module provides a type alias curve25519_dalek::field::FieldElement to either FieldElement51 or FieldElement2625.

The backend-specific type FieldElement51 should not be used outside of the curve25519_dalek::field module.

Implementations

impl FieldElement51

pub const ZERO: FieldElement51

The scalar \( 0 \).

pub const ONE: FieldElement51

The scalar \( 1 \).

pub const MINUS_ONE: FieldElement51

The scalar \( -1 \).

pub fn negate(&mut self)

Invert the sign of this field element

pub fn from_bytes(bytes: &[u8; 32]) -> FieldElement51

Load a FieldElement51 from the low 255 bits of a 256-bit input.

Warning

This function does not check that the input used the canonical representative. It masks the high bit, but it will happily decode 2^255 - 18 to 1. Applications that require a canonical encoding of every field element should decode, re-encode to the canonical encoding, and check that the input was canonical.

pub fn as_bytes(&self) -> [u8; 32]

Serialize this FieldElement51 to a 32-byte array. The encoding is canonical.

pub fn pow2k(&self, k: u32) -> FieldElement51

Given k > 0, return self^(2^k).

pub fn square(&self) -> FieldElement51

Returns the square of this field element.

pub fn square2(&self) -> FieldElement51

Returns 2 times the square of this field element.

Trait Implementations

impl<'a, 'b> Add<&'b FieldElement51> for &'a FieldElement51

type Output = FieldElement51

The resulting type after applying the + operator.

fn add(self, _rhs: &'b FieldElement51) -> FieldElement51

Performs the + operation.

impl<'b> AddAssign<&'b FieldElement51> for FieldElement51

fn add_assign(&mut self, _rhs: &'b FieldElement51)

Performs the += operation.

impl Clone for FieldElement51

fn clone(&self) -> FieldElement51

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl ConditionallySelectable for FieldElement51

fn conditional_select( a: &FieldElement51, b: &FieldElement51, choice: Choice, ) -> FieldElement51

Select a or b according to choice.

fn conditional_swap( a: &mut FieldElement51, b: &mut FieldElement51, choice: Choice, )

Conditionally swap self and other if choice == 1; otherwise, reassign both unto themselves.

fn conditional_assign(&mut self, other: &FieldElement51, choice: Choice)

Conditionally assign other to self, according to choice.

impl ConstantTimeEq for FieldElement51

fn ct_eq(&self, other: &FieldElement51) -> Choice

Test equality between two FieldElements. Since the internal representation is not canonical, the field elements are normalized to wire format before comparison.

fn ct_ne(&self, other: &Self) -> Choice

Determine if two items are NOT equal.

impl Copy for FieldElement51

impl Debug for FieldElement51

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

Formats the value using the given formatter.

impl Eq for FieldElement51

#[doc(hidden)]

fn assert_receiver_is_total_eq(&self)

👎Deprecated since 1.95.0:

implementation detail of #[derive(Eq)]

#[doc(hidden)]

fn assert_fields_are_eq(&self)

🔬This is a nightly-only experimental API. (derive_eq_internals)

impl<'a, 'b> Mul<&'b FieldElement51> for &'a FieldElement51

type Output = FieldElement51

The resulting type after applying the * operator.

fn mul(self, _rhs: &'b FieldElement51) -> FieldElement51

Performs the * operation.

impl<'b> MulAssign<&'b FieldElement51> for FieldElement51

fn mul_assign(&mut self, _rhs: &'b FieldElement51)

Performs the *= operation.

impl<'a> Neg for &'a FieldElement51

type Output = FieldElement51

The resulting type after applying the - operator.

fn neg(self) -> FieldElement51

Performs the unary - operation.

impl PartialEq for FieldElement51

fn eq(&self, other: &FieldElement51) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'a, 'b> Sub<&'b FieldElement51> for &'a FieldElement51

type Output = FieldElement51

The resulting type after applying the - operator.

fn sub(self, _rhs: &'b FieldElement51) -> FieldElement51

Performs the - operation.

impl<'b> SubAssign<&'b FieldElement51> for FieldElement51

fn sub_assign(&mut self, _rhs: &'b FieldElement51)

Performs the -= operation.

impl TrivialClone for FieldElement51

impl Zeroize for FieldElement51

Available on crate feature zeroize only.

fn zeroize(&mut self)

Zero out this object from memory using Rust intrinsics which ensure the zeroization operation is not “optimized away” by the compiler.