Struct Ed448Point 

pub struct Ed448Point { /* private fields */ }

A point on edwards448 in projective coordinates (X : Y : Z).

Affine (x, y) = (X/Z, Y/Z). The neutral element is (0 : 1 : 1). Addition and doubling use the unified projective formulas from the RFC 8032 reference code (originally from the EFD), valid for the untwisted Edwards curve a = 1, d = -39081.

Implementations

impl Ed448Point

pub fn identity() -> Self

The neutral element (0 : 1 : 1).

pub fn base() -> Self

The standard base point B (RFC 8032 §5.2).

pub fn add(&self, q: &Ed448Point) -> Ed448Point

Point addition (unified projective formula, RFC 8032 ref code).

pub fn double(&self) -> Ed448Point

Point doubling (projective formula, RFC 8032 ref code).

pub fn ct_select(a: &Ed448Point, b: &Ed448Point, choice: u8) -> Ed448Point

Branchless point select: returns b if choice == 1, else a.

pub fn scalar_mul(&self, scalar_le: &[u8]) -> Ed448Point

Scalar multiplication [k]·self, constant-time in k.

scalar_le is the little-endian byte encoding of k; every bit (MSB→LSB) performs one double and one masked add, so the operation sequence is independent of the scalar value.

pub fn equals(&self, q: &Ed448Point) -> bool

Projective equality: self == q iff X1·Z2 == X2·Z1 && Y1·Z2 == Y2·Z1.

pub fn is_identity(&self) -> bool

true if this is the neutral element (0 : 1 : 1) (projectively).

pub fn encode(&self) -> [u8; 57]

Encode to the 57-octet RFC 8032 representation: little-endian y (448 bits) with the sign bit of x in bit 455 (MSB of octet 56).

pub fn decode(s: &[u8; 57]) -> Option<Ed448Point>

Decode a 57-octet RFC 8032 point encoding. Returns None if the encoding is non-canonical or x cannot be recovered.

Operates on public data (public key / signature R).

Trait Implementations

impl Clone for Ed448Point

fn clone(&self) -> Ed448Point

Returns a duplicate of the value.

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

Performs copy-assignment from source.