ark-curves-cherry-picked/bn254/src/curves/g1.rs
bn254/src/curves/g1.rsRaw
1use ark_ec::{
2 bn,
3 models::{short_weierstrass::SWCurveConfig, CurveConfig},
4 scalar_mul::glv::GLVConfig,
5 short_weierstrass::{Affine, Projective},
6};
7use ark_ff::{AdditiveGroup, BigInt, Field, MontFp, PrimeField, Zero};
8
9use crate::{Fq, Fr};
10
11#[derive(Clone, Default, PartialEq, Eq)]
12pub struct Config;
13
14pub type G1Affine = Affine<Config>;
15
16impl CurveConfig for Config {
17 type BaseField = Fq;
18 type ScalarField = Fr;
19
20 /// COFACTOR = 1
21 const COFACTOR: &'static [u64] = &[0x1];
22
23 /// COFACTOR_INV = COFACTOR^{-1} mod r = 1
24 const COFACTOR_INV: Fr = Fr::ONE;
25}
26
27impl SWCurveConfig for Config {
28 /// COEFF_A = 0
29 const COEFF_A: Fq = Fq::ZERO;
30
31 /// COEFF_B = 3
32 const COEFF_B: Fq = MontFp!("3");
33
34 /// AFFINE_GENERATOR_COEFFS = (G1_GENERATOR_X, G1_GENERATOR_Y)
35 const GENERATOR: G1Affine = G1Affine::new_unchecked(G1_GENERATOR_X, G1_GENERATOR_Y);
36
37 #[inline(always)]
38 fn mul_by_a(_: Self::BaseField) -> Self::BaseField {
39 Self::BaseField::zero()
40 }
41
42 #[inline]
43 fn mul_projective(
44 p: &bn::G1Projective<crate::Config>,
45 scalar: &[u64],
46 ) -> bn::G1Projective<crate::Config> {
47 let s = Self::ScalarField::from_sign_and_limbs(true, scalar);
48 GLVConfig::glv_mul_projective(*p, s)
49 }
50}
51
52impl GLVConfig for Config {
53 const ENDO_COEFFS: &'static [Self::BaseField] = &[MontFp!(
54 "21888242871839275220042445260109153167277707414472061641714758635765020556616"
55 )];
56
57 const LAMBDA: Self::ScalarField =
58 MontFp!("21888242871839275217838484774961031246154997185409878258781734729429964517155");
59
60 const SCALAR_DECOMP_COEFFS: [(bool, <Self::ScalarField as PrimeField>::BigInt); 4] = [
61 (false, BigInt!("147946756881789319000765030803803410728")),
62 (true, BigInt!("9931322734385697763")),
63 (false, BigInt!("9931322734385697763")),
64 (false, BigInt!("147946756881789319010696353538189108491")),
65 ];
66
67 fn endomorphism(p: &Projective<Self>) -> Projective<Self> {
68 let mut res = (*p).clone();
69 res.x *= Self::ENDO_COEFFS[0];
70 res
71 }
72 fn endomorphism_affine(p: &Affine<Self>) -> Affine<Self> {
73 let mut res = (*p).clone();
74 res.x *= Self::ENDO_COEFFS[0];
75 res
76 }
77}
78
79/// G1_GENERATOR_X = 1
80pub const G1_GENERATOR_X: Fq = Fq::ONE;
81
82/// G1_GENERATOR_Y = 2
83pub const G1_GENERATOR_Y: Fq = MontFp!("2");