Trait BatchInvert 

pub trait BatchInvert: Field {
    // Provided methods
    fn batch_invert_in_place(
        elements: &mut [Self],
        scratch_space: &mut [Self],
    ) -> Self { ... }
    fn batch_invert_in_place_vartime(
        elements: &mut [Self],
        scratch_space: &mut [Self],
    ) -> Self { ... }
}

Perform a batched inversion on a slice of field elements (i.e. base field elements or scalars) at an amortized cost that should be practically as efficient as a single inversion, writing the field element inversions into element, and utilizing scratch as temporary storage.

Note: the ff crate also provides ff::BatchInvert, however that trait has a hard requirement on alloc whereas this one is always available, even in no_alloc contexts.

Panics

If elements and scratch are not the same length.

Provided Methods

fn batch_invert_in_place( elements: &mut [Self], scratch_space: &mut [Self], ) -> Self

Inverts each field element in elements (when non-zero). Zero-valued elements are left as zero.

scratch_space is a slice of field elements that can be freely overwritten.

Returns the inverse of the product of all non-zero field elements.

Panics

If elements.len() != scratch_space.len().

fn batch_invert_in_place_vartime( elements: &mut [Self], scratch_space: &mut [Self], ) -> Self

Variable-time batch inversion.

Security Warning

This should NOT be used on secret values!

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors