Struct BivarPoly 

pub struct BivarPoly { /* private fields */ }

A symmetric bivariate polynomial in the prime field.

This can be used for Verifiable Secret Sharing and Distributed Key Generation. See the module documentation for details.

A bivariate polynomial f(x, y) is symmetric if f(x, y) = f(y, x) for all x and y. This property is essential for distributed key generation protocols.

Example

use threshold_pairing::poly::BivarPoly;

let mut rng = rand::thread_rng();
let bi_poly = BivarPoly::random(2, &mut rng);

// The polynomial is symmetric
let val_xy = bi_poly.evaluate(3u64, 5u64);
let val_yx = bi_poly.evaluate(5u64, 3u64);
assert_eq!(val_xy, val_yx);

// Extract a row as a univariate polynomial
let row = bi_poly.row(1u64);
assert_eq!(row.degree(), bi_poly.degree());

// Get the public commitment
let commitment = bi_poly.commitment();

Security

The polynomial coefficients are zeroized on drop to prevent secret leakage.

Implementations

impl BivarPoly

pub fn random<R: RngCore>(degree: usize, rng: &mut R) -> Self

Creates a random polynomial.

Panics

Panics if the degree is too high for the coefficients to fit into a Vec.

pub fn try_random<R: RngCore>(degree: usize, rng: &mut R) -> Result<Self>

Creates a random polynomial.

pub fn degree(&self) -> usize

Returns the polynomial’s degree; which is the same in both variables.

pub fn evaluate<T: IntoScalar>(&self, x: T, y: T) -> Scalar

Returns the polynomial’s value at the point (x, y).

pub fn row<T: IntoScalar>(&self, x: T) -> Poly

Returns the x-th row, as a univariate polynomial.

pub fn commitment(&self) -> BivarCommitment

Returns the corresponding commitment. That information can be shared publicly.

Trait Implementations

impl Clone for BivarPoly

fn clone(&self) -> BivarPoly

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BivarPoly

A debug statement where the coeff vector has been redacted.

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

Formats the value using the given formatter.

impl Drop for BivarPoly

fn drop(&mut self)

Executes the destructor for this type.

impl Zeroize for BivarPoly

fn zeroize(&mut self)

Zero out this object from memory using Rust intrinsics which ensure the zeroization operation is not “optimized away” by the compiler.