k256 0.14.0

secp256k1 elliptic curve library written in pure Rust with support for ECDSA signing/verification/public-key recovery, Taproot Schnorr signatures (BIP340), Elliptic Curve Diffie-Hellman (ECDH), and general-purpose secp256k1 elliptic curve group operations which can be used to implement arbitrary protocols
Documentation 
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//! A pure-Rust implementation of group operations on secp256k1.

pub(crate) mod affine;
mod field;
mod mul;
pub(crate) mod projective;
pub(crate) mod scalar;

#[cfg(test)]
mod dev;
#[cfg(feature = "hash2curve")]
mod hash2curve;
#[cfg(feature = "precomputed-tables")]
mod tables;

pub use field::FieldElement;

use self::{affine::AffinePoint, projective::ProjectivePoint, scalar::Scalar};
use crate::Secp256k1;
use elliptic_curve::{CurveArithmetic, hazmat::FieldArithmetic};

impl CurveArithmetic for Secp256k1 {
    type AffinePoint = AffinePoint;
    type ProjectivePoint = ProjectivePoint;
    type Scalar = Scalar;
}

impl FieldArithmetic for Secp256k1 {
    type FieldElement = FieldElement;
}

const CURVE_EQUATION_B_SINGLE: u32 = 7u32;

#[rustfmt::skip]
#[allow(clippy::cast_possible_truncation)]
pub(crate) const CURVE_EQUATION_B: FieldElement = FieldElement::from_bytes_unchecked(&[
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, CURVE_EQUATION_B_SINGLE as u8,
]);

#[cfg(test)]
mod tests {
    use super::CURVE_EQUATION_B;
    use hex_literal::hex;

    const CURVE_EQUATION_B_BYTES: [u8; 32] =
        hex!("0000000000000000000000000000000000000000000000000000000000000007");

    #[test]
    fn verify_constants() {
        assert_eq!(CURVE_EQUATION_B.to_bytes(), CURVE_EQUATION_B_BYTES);
    }
}