Trait ff::Field

pub trait Field: Sized + Eq + Copy + Clone + Default + Send + Sync + Debug + 'static + ConditionallySelectable + ConstantTimeEq + Add<Output = Self> + Sub<Output = Self> + Mul<Output = Self> + Neg<Output = Self> + for<'a> Add<&'a Self, Output = Self> + for<'a> Mul<&'a Self, Output = Self> + for<'a> Sub<&'a Self, Output = Self> + MulAssign + AddAssign + SubAssign + for<'a> MulAssign<&'a Self> + for<'a> AddAssign<&'a Self> + for<'a> SubAssign<&'a Self> {
    // Required methods
    fn random(rng: impl RngCore) -> Self;
    fn zero() -> Self;
    fn one() -> Self;
    fn square(&self) -> Self;
    fn double(&self) -> Self;
    fn invert(&self) -> CtOption<Self>;
    fn sqrt(&self) -> CtOption<Self>;

    // Provided methods
    fn is_zero(&self) -> Choice { ... }
    fn is_zero_vartime(&self) -> bool { ... }
    fn cube(&self) -> Self { ... }
    fn pow_vartime<S: AsRef<[u64]>>(&self, exp: S) -> Self { ... }
}

This trait represents an element of a field.

Required Methods

fn random(rng: impl RngCore) -> Self

Returns an element chosen uniformly at random using a user-provided RNG.

fn zero() -> Self

Returns the zero element of the field, the additive identity.

fn one() -> Self

Returns the one element of the field, the multiplicative identity.

fn square(&self) -> Self

Squares this element.

fn double(&self) -> Self

Doubles this element.

fn invert(&self) -> CtOption<Self>

Computes the multiplicative inverse of this element, failing if the element is zero.

fn sqrt(&self) -> CtOption<Self>

Returns the square root of the field element, if it is quadratic residue.

Provided Methods

fn is_zero(&self) -> Choice

Returns true iff this element is zero.

fn is_zero_vartime(&self) -> bool

Returns true iff this element is zero.

Security

This method provides no constant-time guarantees. Implementors of the Field trait may optimise this method using non-constant-time logic.

fn cube(&self) -> Self

Cubes this element.

fn pow_vartime<S: AsRef<[u64]>>(&self, exp: S) -> Self

Exponentiates self by exp, where exp is a little-endian order integer exponent.

This operation is variable time with respect to the exponent. If the exponent is fixed, this operation is effectively constant time.

Object Safety

This trait is not object safe.

Implementors