Struct Fp 

pub struct Fp(pub [u64; 9]);

The P-521 coordinate field, GF(p) with p = 2^521 - 1.

Values are held in Montgomery form (a * R mod m). Arithmetic is branch-free and carries no data-dependent memory access.

Tuple Fields

0: [u64; 9]

Implementations

impl Fp

pub const MODULUS: [u64; 9]

The modulus, as little-endian 64-bit limbs.

pub fn to_mont(limbs: [u64; 9]) -> Self

Convert a plain integer into Montgomery form, in constant time.

pub const fn to_mont_const(limbs: [u64; 9]) -> Self

Self::to_mont for a curve constant, evaluated at compile time. Not for secrets: it skips the barrier to_mont has.

pub fn from_mont(&self) -> [u64; 9]

Convert out of Montgomery form, in constant time.

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

Repeated squaring, self^(2^n).

pub fn pow(&self, exponent: &[u64; 9]) -> Self

Exponentiation by a public exponent, square-and-multiply.

The exponent is always a fixed constant here (m - 2 for inversion, (p + 1) / 4 for square roots), so branching on its bits leaks nothing; the base stays secret throughout.

Trait Implementations

impl Clone for Fp

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 Fp

impl Debug for Fp

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

Formats the value using the given formatter.

impl Eq for Fp

impl PartialEq for Fp

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Fp