Struct prio::field::Field128

pub struct Field128(/* private fields */);

GF(340282366920938462946865773367900766209), a 128-bit field.

This structure represents a field element in a prime order field. The concrete representation of the element is via the Montgomery domain. For an element n in GF(p), we store n * R^-1 mod p (where R is a given power of two). This representation enables using a more efficient (and branchless) multiplication algorithm, at the expense of having to convert elements between their Montgomery domain representation and natural representation. For calculations with many multiplications or exponentiations, this is worthwhile.

As an invariant, this integer representing the field element in the Montgomery domain must be less than the field modulus, p.

Trait Implementations

impl Add for &Field128

type Output = Field128

The resulting type after applying the + operator.

fn add(self, rhs: Self) -> Field128

Performs the + operation.

impl Add for Field128

type Output = Field128

The resulting type after applying the + operator.

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

Performs the + operation.

impl AddAssign for Field128

fn add_assign(&mut self, rhs: Self)

Performs the += operation.

impl Clone for Field128

fn clone(&self) -> Field128

Returns a copy of the value.

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

Performs copy-assignment from source.

impl ConditionallySelectable for Field128

fn conditional_select(a: &Self, b: &Self, choice: Choice) -> Self

Select a or b according to choice.

fn conditional_assign(&mut self, other: &Self, choice: Choice)

Conditionally assign other to self, according to choice.

fn conditional_swap(a: &mut Self, b: &mut Self, choice: Choice)

Conditionally swap self and other if choice == 1; otherwise, reassign both unto themselves.

impl ConstantTimeEq for Field128

fn ct_eq(&self, rhs: &Self) -> Choice

Determine if two items are equal.

fn ct_ne(&self, other: &Self) -> Choice

Determine if two items are NOT equal.

impl Debug for Field128

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

Formats the value using the given formatter.

impl Decode for Field128

fn decode(bytes: &mut Cursor<&[u8]>) -> Result<Self, CodecError>

Read and decode an encoded object from bytes. On success, the decoded value is returned and bytes is advanced by the encoded size of the value. On failure, an error is returned and no further attempt to read from bytes should be made.

fn get_decoded(bytes: &[u8]) -> Result<Self, CodecError>

Convenience method to get a decoded value. Returns an error if Self::decode fails, or if there are any bytes left in bytes after decoding a value.

impl Default for Field128

fn default() -> Field128

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Field128

fn deserialize<D: Deserializer<'de>>( deserializer: D ) -> Result<Field128, D::Error>

Deserialize this value from the given Serde deserializer.

impl Display for Field128

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

Formats the value using the given formatter.

impl Distribution<Field128> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> Field128

Generate a random value of T, using rng as the source of randomness.

fn sample_iter<R>(self, rng: R) -> DistIter<Self, R, T>

where R: Rng, Self: Sized,

Create an iterator that generates random values of T, using rng as the source of randomness.

fn map<F, S>(self, func: F) -> DistMap<Self, F, T, S>

where F: Fn(T) -> S, Self: Sized,

Create a distribution of values of ‘S’ by mapping the output of Self through the closure F

impl Div for &Field128

type Output = Field128

The resulting type after applying the / operator.

fn div(self, rhs: Self) -> Field128

Performs the / operation.

impl Div for Field128

type Output = Field128

The resulting type after applying the / operator.

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

Performs the / operation.

impl DivAssign for Field128

fn div_assign(&mut self, rhs: Self)

Performs the /= operation.

impl Encode for Field128

fn encode(&self, bytes: &mut Vec<u8>) -> Result<(), CodecError>

Append the encoded form of this object to the end of bytes, growing the vector as needed.

fn encoded_len(&self) -> Option<usize>

Returns an optional hint indicating how many bytes will be required to encode this value, or None by default.

fn get_encoded(&self) -> Result<Vec<u8>, CodecError>

Convenience method to encode a value into a new Vec<u8>.

impl FftFriendlyFieldElement for Field128

fn generator() -> Self

Returns the generator of the multiplicative subgroup of size FftFriendlyFieldElement::generator_order.

fn generator_order() -> Self::Integer

Returns the size of the multiplicative subgroup generated by FftFriendlyFieldElement::generator.

fn root(l: usize) -> Option<Self>

Returns the 2^l-th principal root of unity for any l <= 20. Note that the 2^0-th prinicpal root of unity is 1 by definition.

impl FieldElement for Field128

const ENCODED_SIZE: usize = 16usize

Size in bytes of an encoded field element.

fn inv(&self) -> Self

Modular inversion, i.e., self^-1 (mod p). If self is 0, then the output is undefined.

fn zero() -> Self

Returns the additive identity.

fn one() -> Self

Returns the multiplicative identity.

fn slice_into_byte_vec(values: &[Self]) -> Vec<u8>

👎Deprecated

Convert a slice of field elements into a vector of bytes.

fn byte_slice_into_vec(bytes: &[u8]) -> Result<Vec<Self>, FieldError>

👎Deprecated

Convert a slice of bytes into a vector of field elements. The slice is interpreted as a sequence of Self::ENCODED_SIZE-byte sequences.

impl FieldElementWithInteger for Field128

type Integer = u128

The integer representation of a field element.

fn pow(&self, exp: Self::Integer) -> Self

Modular exponentation, i.e., self^exp (mod p).

fn modulus() -> Self::Integer

Returns the prime modulus p.

fn encode_as_bitvector( input: Self::Integer, bits: usize ) -> Result<BitvectorRepresentationIter<Self>, FieldError>

Encode the integer input as a sequence of bits in two’s complement representation, least significant bit first, and then map each bit to a field element.

fn decode_bitvector(input: &[Self]) -> Result<Self, FieldError>

Inverts the encoding done by Self::encode_as_bitvector, and returns a single field element.

impl From<Field128> for [u8; 16]

fn from(elem: Field128) -> Self

Converts to this type from the input type.

impl From<Field128> for Vec<u8>

fn from(elem: Field128) -> Self

Converts to this type from the input type.

impl From<Field128> for u128

fn from(x: Field128) -> Self

Converts to this type from the input type.

impl From<u128> for Field128

fn from(x: u128) -> Self

Converts to this type from the input type.

impl Hash for Field128

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Mul for &Field128

type Output = Field128

The resulting type after applying the * operator.

fn mul(self, rhs: Self) -> Field128

Performs the * operation.

impl Mul for Field128

type Output = Field128

The resulting type after applying the * operator.

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

Performs the * operation.

impl MulAssign for Field128

fn mul_assign(&mut self, rhs: Self)

Performs the *= operation.

impl Neg for &Field128

type Output = Field128

The resulting type after applying the - operator.

fn neg(self) -> Field128

Performs the unary - operation.

impl Neg for Field128

type Output = Field128

The resulting type after applying the - operator.

fn neg(self) -> Self

Performs the unary - operation.

impl PartialEq<u128> for Field128

fn eq(&self, rhs: &u128) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq for Field128

fn eq(&self, rhs: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for Field128

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl Sub for &Field128

type Output = Field128

The resulting type after applying the - operator.

fn sub(self, rhs: Self) -> Field128

Performs the - operation.

impl Sub for Field128

type Output = Field128

The resulting type after applying the - operator.

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

Performs the - operation.

impl SubAssign for Field128

fn sub_assign(&mut self, rhs: Self)

Performs the -= operation.

impl<'a> TryFrom<&'a [u8]> for Field128

type Error = FieldError

The type returned in the event of a conversion error.

fn try_from(bytes: &[u8]) -> Result<Self, FieldError>

Performs the conversion.

impl Copy for Field128

impl Eq for Field128