Struct curve25519_dalek::scalar::Scalar
[−]
[src]
pub struct Scalar(pub [u8; 32]);
The Scalar struct represents an element in ℤ/lℤ, where
l = 2252 + 27742317777372353535851937790883648493
is the order of the basepoint.
Methods
impl Scalar[src]
fn zero() -> Self
Construct the additive identity
fn one() -> Self
Construct the multiplicative identity
fn non_adjacent_form(&self) -> [i8; 256]
Compute a width-5 "Non-Adjacent Form" of this scalar.
A width-w NAF of a positive integer k is an expression
k = sum(k[i]*2^i for i in range(l)), where each nonzero
coefficient k[i] is odd and bounded by |k[i]| < 2^(w-1),
k[l-1] is nonzero, and at most one of any w consecutive
coefficients is nonzero. (Hankerson, Menezes, Vanstone; def 3.32).
Intuitively, this is like a binary expansion, except that we
allow some coefficients to grow up to 2^(w-1) so that the
nonzero coefficients are as sparse as possible.
fn to_radix_16(&self) -> [i8; 64]
Write this scalar in radix 16, with coefficients in [-8,8),
i.e., compute a_i such that
a = a_0 + a_1*161 + ... + a_63*1663,
with -8 ≤ a_i < 8 for 0 ≤ i < 63 and -8 ≤ a_63 ≤ 8.
Precondition: self[31] <= 127. This is the case whenever
self is reduced.
fn multiply_add(a: &Scalar, b: &Scalar, c: &Scalar) -> Scalar
Compute ab+c (mod l).
fn reduce(input: &[u8; 64]) -> Scalar
Reduce a 512-bit little endian number mod l
Trait Implementations
impl Copy for Scalar[src]
impl Clone for Scalar[src]
fn clone(&self) -> Scalar
Returns a copy of the value. Read more
fn clone_from(&mut self, source: &Self)1.0.0
Performs copy-assignment from source. Read more
impl Index<usize> for Scalar[src]
type Output = u8
The returned type after indexing
fn index<'a>(&'a self, _index: usize) -> &'a u8
The method for the indexing (container[index]) operation