pub struct Scalar(_);arithmetic only.Expand description
Scalars are elements in the finite field modulo n.
Trait impls
Much of the important functionality of scalars is provided by traits from
the ff crate, which is re-exported as
p256::elliptic_curve::ff:
Field- represents elements of finite fields and provides:Field::random- generate a random scalardouble,square, andinvertoperations- Bounds for
Add,Sub,Mul, andNeg(as well as*Assignequivalents) - Bounds for
ConditionallySelectablefrom thesubtlecrate
PrimeField- represents elements of prime fields and provides:from_repr/to_reprfor converting field elements from/to big integers.multiplicative_generatorandroot_of_unityconstants.
PrimeFieldBits- operations over field elements represented as bits (requiresbitsfeature)
Please see the documentation for the relevant traits for more information.
serde support
When the serde feature of this crate is enabled, the Serialize and
Deserialize traits are impl’d for this type.
The serialization is a fixed-width big endian encoding. When used with textual formats, the binary data is encoded as hexadecimal.
Implementations
Returns the SEC1 encoding of this scalar.
Returns the multiplicative inverse of self, if self is non-zero
Faster inversion using Stein’s algorithm
Trait Implementations
Performs the += operation. Read more
Performs the += operation. Read more
Deserialize this value from the given Serde deserializer. Read more
Tonelli-Shank’s algorithm for q mod 16 = 1 https://eprint.iacr.org/2012/685.pdf (page 12, algorithm 5)
Returns an element chosen uniformly at random using a user-provided RNG.
Computes the multiplicative inverse of this element, failing if the element is zero. Read more
fn is_zero_vartime(&self) -> bool
fn is_zero_vartime(&self) -> bool
Returns true iff this element is zero. Read more
fn cube(&self) -> Self
fn cube(&self) -> Self
Cubes this element.
Performs the conversion.
Performs the conversion.
Performs the conversion.
Performs the conversion.
Performs the conversion.
type Output = ProjectivePoint
type Output = ProjectivePoint
The resulting type after applying the * operator.
Performs the * operation. Read more
type Output = ProjectivePoint
type Output = ProjectivePoint
The resulting type after applying the * operator.
Performs the * operation. Read more
type Output = ProjectivePoint
type Output = ProjectivePoint
The resulting type after applying the * operator.
Performs the * operation. Read more
type Output = ProjectivePoint
type Output = ProjectivePoint
The resulting type after applying the * operator.
Performs the * operation. Read more
type Output = ProjectivePoint
type Output = ProjectivePoint
The resulting type after applying the * operator.
Performs the * operation. Read more
Performs the *= operation. Read more
Performs the *= operation. Read more
Performs the *= operation. Read more
Performs the *= operation. Read more
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <=
operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
Attempts to parse the given byte array as an SEC1-encoded scalar.
Returns None if the byte array does not contain a big-endian integer in the range [0, p).
type Repr = FieldBytes
type Repr = FieldBytes
The prime field can be converted back and forth into this binary representation. Read more
How many bits of information can be reliably stored in the field element. Read more
Converts an element of the prime field into the standard byte representation for this field. Read more
Returns a fixed multiplicative generator of modulus - 1 order. This element must
also be a quadratic nonresidue. Read more
Returns the 2^s root of unity. Read more
fn from_str_vartime(s: &str) -> Option<Self>
fn from_str_vartime(s: &str) -> Option<Self>
Interpret a string of numbers as a (congruent) prime field element. Does not accept unnecessary leading zeroes or a blank string. Read more
fn from_repr_vartime(repr: Self::Repr) -> Option<Self>
fn from_repr_vartime(repr: Self::Repr) -> Option<Self>
Attempts to convert a byte representation of a field element into an element of this prime field, failing if the input is not canonical (is not smaller than the field’s modulus). Read more
Converts an element of the prime field into a little-endian sequence of bits.
Returns the bits of the field characteristic (the modulus) in little-endian order.
Perform a modular reduction, returning a field element.
Interpret the given byte array as a big endian integer and perform a modular reduction. Read more
Interpret the given byte array as a little endian integer and perform a modular reduction. Read more
fn from_be_digest_reduced<D>(digest: D) -> Self where
D: FixedOutput<OutputSize = <UInt as ArrayEncoding>::ByteSize> + BlockInput + Clone + Default + Reset + Update,
fn from_be_digest_reduced<D>(digest: D) -> Self where
D: FixedOutput<OutputSize = <UInt as ArrayEncoding>::ByteSize> + BlockInput + Clone + Default + Reset + Update,
Interpret a digest as a big endian integer and perform a modular reduction. Read more
fn from_le_digest_reduced<D>(digest: D) -> Self where
D: FixedOutput<OutputSize = <UInt as ArrayEncoding>::ByteSize> + BlockInput + Clone + Default + Reset + Update,
fn from_le_digest_reduced<D>(digest: D) -> Self where
D: FixedOutput<OutputSize = <UInt as ArrayEncoding>::ByteSize> + BlockInput + Clone + Default + Reset + Update,
Interpret a digest as a little endian integer and perform a modular reduction. Read more
Perform a modular reduction, returning a field element.
fn try_sign_prehashed<K>(
&self,
k: K,
z: <C as ScalarArithmetic>::Scalar
) -> Result<(Signature<C>, Option<RecoveryId>), Error> where
K: Borrow<Self> + Invert<Output = Self>,
fn try_sign_prehashed<K>(
&self,
k: K,
z: <C as ScalarArithmetic>::Scalar
) -> Result<(Signature<C>, Option<RecoveryId>), Error> where
K: Borrow<Self> + Invert<Output = Self>,
Try to sign the prehashed message. Read more
Performs the -= operation. Read more
Performs the -= operation. Read more
Auto Trait Implementations
impl RefUnwindSafe for Scalar
impl UnwindSafe for Scalar
Blanket Implementations
Mutably borrows from an owned value. Read more
impl<T> ConditionallyNegatable for T where
T: ConditionallySelectable,
&'a T: for<'a> Neg,
<&'a T as Neg>::Output == T,
impl<T> ConditionallyNegatable for T where
T: ConditionallySelectable,
&'a T: for<'a> Neg,
<&'a T as Neg>::Output == T,
Negate self if choice == Choice(1); otherwise, leave it
unchanged. Read more
fn fmt_binary(self) -> FmtBinary<Self> where
Self: Binary,
fn fmt_binary(self) -> FmtBinary<Self> where
Self: Binary,
Causes self to use its Binary implementation when Debug-formatted.
fn fmt_display(self) -> FmtDisplay<Self> where
Self: Display,
fn fmt_display(self) -> FmtDisplay<Self> where
Self: Display,
Causes self to use its Display implementation when
Debug-formatted. Read more
fn fmt_lower_exp(self) -> FmtLowerExp<Self> where
Self: LowerExp,
fn fmt_lower_exp(self) -> FmtLowerExp<Self> where
Self: LowerExp,
Causes self to use its LowerExp implementation when
Debug-formatted. Read more
fn fmt_lower_hex(self) -> FmtLowerHex<Self> where
Self: LowerHex,
fn fmt_lower_hex(self) -> FmtLowerHex<Self> where
Self: LowerHex,
Causes self to use its LowerHex implementation when
Debug-formatted. Read more
Causes self to use its Octal implementation when Debug-formatted.
fn fmt_pointer(self) -> FmtPointer<Self> where
Self: Pointer,
fn fmt_pointer(self) -> FmtPointer<Self> where
Self: Pointer,
Causes self to use its Pointer implementation when
Debug-formatted. Read more
fn fmt_upper_exp(self) -> FmtUpperExp<Self> where
Self: UpperExp,
fn fmt_upper_exp(self) -> FmtUpperExp<Self> where
Self: UpperExp,
Causes self to use its UpperExp implementation when
Debug-formatted. Read more
fn fmt_upper_hex(self) -> FmtUpperHex<Self> where
Self: UpperHex,
fn fmt_upper_hex(self) -> FmtUpperHex<Self> where
Self: UpperHex,
Causes self to use its UpperHex implementation when
Debug-formatted. Read more
impl<T> Pipe for T where
T: ?Sized,
impl<T> Pipe for T where
T: ?Sized,
Pipes by value. This is generally the method you want to use. Read more
Borrows self and passes that borrow into the pipe function. Read more
fn pipe_ref_mut<'a, R>(&'a mut self, func: impl FnOnce(&'a mut Self) -> R) -> R where
R: 'a,
fn pipe_ref_mut<'a, R>(&'a mut self, func: impl FnOnce(&'a mut Self) -> R) -> R where
R: 'a,
Mutably borrows self and passes that borrow into the pipe function. Read more
fn pipe_borrow<'a, B, R>(&'a self, func: impl FnOnce(&'a B) -> R) -> R where
Self: Borrow<B>,
B: 'a + ?Sized,
R: 'a,
fn pipe_borrow<'a, B, R>(&'a self, func: impl FnOnce(&'a B) -> R) -> R where
Self: Borrow<B>,
B: 'a + ?Sized,
R: 'a,
Borrows self, then passes self.borrow() into the pipe function. Read more
fn pipe_borrow_mut<'a, B, R>(
&'a mut self,
func: impl FnOnce(&'a mut B) -> R
) -> R where
Self: BorrowMut<B>,
B: 'a + ?Sized,
R: 'a,
fn pipe_borrow_mut<'a, B, R>(
&'a mut self,
func: impl FnOnce(&'a mut B) -> R
) -> R where
Self: BorrowMut<B>,
B: 'a + ?Sized,
R: 'a,
Mutably borrows self, then passes self.borrow_mut() into the pipe
function. Read more
fn pipe_as_ref<'a, U, R>(&'a self, func: impl FnOnce(&'a U) -> R) -> R where
Self: AsRef<U>,
U: 'a + ?Sized,
R: 'a,
fn pipe_as_ref<'a, U, R>(&'a self, func: impl FnOnce(&'a U) -> R) -> R where
Self: AsRef<U>,
U: 'a + ?Sized,
R: 'a,
Borrows self, then passes self.as_ref() into the pipe function.
fn pipe_as_mut<'a, U, R>(&'a mut self, func: impl FnOnce(&'a mut U) -> R) -> R where
Self: AsMut<U>,
U: 'a + ?Sized,
R: 'a,
fn pipe_as_mut<'a, U, R>(&'a mut self, func: impl FnOnce(&'a mut U) -> R) -> R where
Self: AsMut<U>,
U: 'a + ?Sized,
R: 'a,
Mutably borrows self, then passes self.as_mut() into the pipe
function. Read more
fn pipe_deref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R where
Self: Deref<Target = T>,
T: 'a + ?Sized,
R: 'a,
fn pipe_deref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R where
Self: Deref<Target = T>,
T: 'a + ?Sized,
R: 'a,
Borrows self, then passes self.deref() into the pipe function.
fn tap_borrow<B>(self, func: impl FnOnce(&B)) -> Self where
Self: Borrow<B>,
B: ?Sized,
fn tap_borrow<B>(self, func: impl FnOnce(&B)) -> Self where
Self: Borrow<B>,
B: ?Sized,
Immutable access to the Borrow<B> of a value. Read more
fn tap_borrow_mut<B>(self, func: impl FnOnce(&mut B)) -> Self where
Self: BorrowMut<B>,
B: ?Sized,
fn tap_borrow_mut<B>(self, func: impl FnOnce(&mut B)) -> Self where
Self: BorrowMut<B>,
B: ?Sized,
Mutable access to the BorrowMut<B> of a value. Read more
Immutable access to the AsRef<R> view of a value. Read more
fn tap_ref_mut<R>(self, func: impl FnOnce(&mut R)) -> Self where
Self: AsMut<R>,
R: ?Sized,
fn tap_ref_mut<R>(self, func: impl FnOnce(&mut R)) -> Self where
Self: AsMut<R>,
R: ?Sized,
Mutable access to the AsMut<R> view of a value. Read more
Immutable access to the Deref::Target of a value. Read more
Mutable access to the Deref::Target of a value. Read more
Calls .tap() only in debug builds, and is erased in release builds.
fn tap_mut_dbg(self, func: impl FnOnce(&mut Self)) -> Self
fn tap_mut_dbg(self, func: impl FnOnce(&mut Self)) -> Self
Calls .tap_mut() only in debug builds, and is erased in release
builds. Read more
fn tap_borrow_dbg<B>(self, func: impl FnOnce(&B)) -> Self where
Self: Borrow<B>,
B: ?Sized,
fn tap_borrow_dbg<B>(self, func: impl FnOnce(&B)) -> Self where
Self: Borrow<B>,
B: ?Sized,
Calls .tap_borrow() only in debug builds, and is erased in release
builds. Read more
fn tap_borrow_mut_dbg<B>(self, func: impl FnOnce(&mut B)) -> Self where
Self: BorrowMut<B>,
B: ?Sized,
fn tap_borrow_mut_dbg<B>(self, func: impl FnOnce(&mut B)) -> Self where
Self: BorrowMut<B>,
B: ?Sized,
Calls .tap_borrow_mut() only in debug builds, and is erased in release
builds. Read more
fn tap_ref_dbg<R>(self, func: impl FnOnce(&R)) -> Self where
Self: AsRef<R>,
R: ?Sized,
fn tap_ref_dbg<R>(self, func: impl FnOnce(&R)) -> Self where
Self: AsRef<R>,
R: ?Sized,
Calls .tap_ref() only in debug builds, and is erased in release
builds. Read more
fn tap_ref_mut_dbg<R>(self, func: impl FnOnce(&mut R)) -> Self where
Self: AsMut<R>,
R: ?Sized,
fn tap_ref_mut_dbg<R>(self, func: impl FnOnce(&mut R)) -> Self where
Self: AsMut<R>,
R: ?Sized,
Calls .tap_ref_mut() only in debug builds, and is erased in release
builds. Read more