Struct Fe 

pub struct Fe(pub [u64; 5]);

A field element modulo 2^255 - 19.

Tuple Fields

0: [u64; 5]

Implementations

impl Fe

pub const ZERO: Fe

The additive identity.

pub const ONE: Fe

The multiplicative identity.

pub const fn from_u64(v: u64) -> Fe

A small integer as a field element.

pub fn add(&self, other: &Fe) -> Fe

Field addition.

pub fn sub(&self, other: &Fe) -> Fe

Field subtraction, via self + 2p - other so limbs stay non-negative.

pub fn neg(&self) -> Fe

Field negation.

pub fn mul(&self, other: &Fe) -> Fe

Field multiplication.

pub fn square(&self) -> Fe

Field squaring.

pub fn square_n(&self, n: usize) -> Fe

Repeated squaring, self^(2^n).

pub fn mul121666(&self) -> Fe

Multiplication by the Montgomery ladder constant a24 = 121666.

pub fn invert(&self) -> Fe

Multiplicative inverse, self^(p-2), with inverse(0) == 0.

Uses the standard addition chain: 254 squarings and 11 multiplications.

pub fn pow22523(&self) -> Fe

self^((p-5)/8), the exponent used to take square roots.

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

Decode 32 little-endian bytes, ignoring the top bit as RFC 7748 requires.

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

Encode as 32 little-endian bytes, fully reduced modulo p.

pub fn cswap(a: &mut Fe, b: &mut Fe, choice: Choice)

Constant-time conditional swap.

pub fn cmov(a: &mut Fe, b: &Fe, choice: Choice)

Constant-time conditional move: a = b when choice is true.

pub fn is_zero(&self) -> Choice

Constant-time test for zero.

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

Constant-time equality.

pub fn is_negative(&self) -> Choice

The least significant bit of the canonical encoding — the “sign” used by Edwards point compression.

Trait Implementations

impl Clone for Fe

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Fe

impl Debug for Fe

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

Formats the value using the given formatter.

impl Eq for Fe

impl PartialEq for Fe

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Fe