ark-curves-cherry-picked/bls12_377/src/curves/g2.rs
bls12_377/src/curves/g2.rsRaw
1use ark_ec::models::{ModelParameters, SWModelParameters};
2use ark_ff::{MontFp, QuadExt, Zero};
3
4use crate::{fields::FQ_ZERO, g1, Fq, Fq2, Fr};
5
6#[derive(Clone, Default, PartialEq, Eq)]
7pub struct Parameters;
8
9impl ModelParameters for Parameters {
10 type BaseField = Fq2;
11 type ScalarField = Fr;
12
13 /// COFACTOR =
14 /// 7923214915284317143930293550643874566881017850177945424769256759165301436616933228209277966774092486467289478618404761412630691835764674559376407658497
15 #[rustfmt::skip]
16 const COFACTOR: &'static [u64] = &[
17 0x0000000000000001,
18 0x452217cc90000000,
19 0xa0f3622fba094800,
20 0xd693e8c36676bd09,
21 0x8c505634fae2e189,
22 0xfbb36b00e1dcc40c,
23 0xddd88d99a6f6a829,
24 0x26ba558ae9562a,
25 ];
26
27 /// COFACTOR_INV = COFACTOR^{-1} mod r
28 /// = 6764900296503390671038341982857278410319949526107311149686707033187604810669
29 const COFACTOR_INV: Fr = MontFp!(
30 Fr,
31 "6764900296503390671038341982857278410319949526107311149686707033187604810669"
32 );
33}
34
35impl SWModelParameters for Parameters {
36 /// COEFF_A = [0, 0]
37 const COEFF_A: Fq2 = QuadExt!(g1::Parameters::COEFF_A, g1::Parameters::COEFF_A,);
38
39 // As per https://eprint.iacr.org/2012/072.pdf,
40 // this curve has b' = b/i, where b is the COEFF_B of G1, and x^6 -i is
41 // the irreducible poly used to extend from Fp2 to Fp12.
42 // In our case, i = u (App A.3, T_6).
43 /// COEFF_B = [0,
44 /// 155198655607781456406391640216936120121836107652948796323930557600032281009004493664981332883744016074664192874906]
45 const COEFF_B: Fq2 = QuadExt!(
46 FQ_ZERO,
47 MontFp!(Fq, "155198655607781456406391640216936120121836107652948796323930557600032281009004493664981332883744016074664192874906"),
48 );
49
50 /// AFFINE_GENERATOR_COEFFS = (G2_GENERATOR_X, G2_GENERATOR_Y)
51 const AFFINE_GENERATOR_COEFFS: (Self::BaseField, Self::BaseField) =
52 (G2_GENERATOR_X, G2_GENERATOR_Y);
53
54 #[inline(always)]
55 fn mul_by_a(_: &Self::BaseField) -> Self::BaseField {
56 Self::BaseField::zero()
57 }
58}
59
60pub const G2_GENERATOR_X: Fq2 = QuadExt!(G2_GENERATOR_X_C0, G2_GENERATOR_X_C1);
61pub const G2_GENERATOR_Y: Fq2 = QuadExt!(G2_GENERATOR_Y_C0, G2_GENERATOR_Y_C1);
62
63/// G2_GENERATOR_X_C0 =
64/// 233578398248691099356572568220835526895379068987715365179118596935057653620464273615301663571204657964920925606294
65pub const G2_GENERATOR_X_C0: Fq = MontFp!(Fq, "233578398248691099356572568220835526895379068987715365179118596935057653620464273615301663571204657964920925606294");
66
67/// G2_GENERATOR_X_C1 =
68/// 140913150380207355837477652521042157274541796891053068589147167627541651775299824604154852141315666357241556069118
69pub const G2_GENERATOR_X_C1: Fq = MontFp!(Fq, "140913150380207355837477652521042157274541796891053068589147167627541651775299824604154852141315666357241556069118");
70
71/// G2_GENERATOR_Y_C0 =
72/// 63160294768292073209381361943935198908131692476676907196754037919244929611450776219210369229519898517858833747423
73pub const G2_GENERATOR_Y_C0: Fq = MontFp!(Fq, "63160294768292073209381361943935198908131692476676907196754037919244929611450776219210369229519898517858833747423");
74
75/// G2_GENERATOR_Y_C1 =
76/// 149157405641012693445398062341192467754805999074082136895788947234480009303640899064710353187729182149407503257491
77pub const G2_GENERATOR_Y_C1: Fq = MontFp!(Fq, "149157405641012693445398062341192467754805999074082136895788947234480009303640899064710353187729182149407503257491");