Struct WideGhashSqProduct 

pub struct WideGhashSqProduct { /* private fields */ }

The unreduced product of two GHASH^2 elements.

Holds the three GHASH widening products of the Karatsuba decomposition, before any reduction.

Take x = x_0 + x_1·Y and y = y_0 + y_1·Y over GHASH, with Y^2 = Y + X^-1. Then z = x·y has coordinates:

• z_0 = x_0·y_0 + (x_1·y_1)·X^-1
• z_1 = (x_0+x_1)·(y_0+y_1) + x_0·y_0

The three scalar products it defers are:

• x_0·y_0 and x_1·y_1, computed together as one packed PackedBinaryGhash2x128b multiply.
• (x_0+x_1)·(y_0+y_1), the Karatsuba cross term, a scalar GHASH multiply.

Both the GHASH reduction and the X^-1 scaling are GF(2)-linear. So a sum of products reduces to the reduction of the XOR of their unreduced forms. An inner product over GHASH^2 then accumulates by XOR and reduces only once at the end.

Trait Implementations

impl Add for WideGhashSqProduct

type Output = WideGhashSqProduct

The resulting type after applying the + operator.

fn add(self, rhs: Self) -> Self

Performs the + operation.

impl AddAssign for WideGhashSqProduct

fn add_assign(&mut self, rhs: Self)

Performs the += operation.

impl Clone for WideGhashSqProduct

fn clone(&self) -> WideGhashSqProduct

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for WideGhashSqProduct

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

Formats the value using the given formatter.

impl Default for WideGhashSqProduct

fn default() -> WideGhashSqProduct

Returns the “default value” for a type.

impl Sub for WideGhashSqProduct

type Output = WideGhashSqProduct

The resulting type after applying the - operator.

fn sub(self, rhs: Self) -> Self

Performs the - operation.

impl SubAssign for WideGhashSqProduct

fn sub_assign(&mut self, rhs: Self)

Performs the -= operation.

impl Sum for WideGhashSqProduct

fn sum<I: Iterator<Item = Self>>(iter: I) -> Self

Takes an iterator and generates Self from the elements by “summing up” the items.

impl Copy for WideGhashSqProduct