ark_ec/models/mnt6/
g2.rs

1use crate::{
2    mnt6::MNT6Config,
3    models::mnt6::MNT6,
4    short_weierstrass::{Affine, Projective},
5    AffineRepr, CurveGroup,
6};
7use ark_ff::fields::{Field, Fp3};
8use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
9use ark_std::{ops::Neg, vec::*};
10use educe::Educe;
11use num_traits::One;
12
13pub type G2Affine<P> = Affine<<P as MNT6Config>::G2Config>;
14pub type G2Projective<P> = Projective<<P as MNT6Config>::G2Config>;
15
16#[derive(Educe, CanonicalSerialize, CanonicalDeserialize)]
17#[educe(Clone, Debug, PartialEq, Eq)]
18pub struct G2Prepared<P: MNT6Config> {
19    pub x: Fp3<P::Fp3Config>,
20    pub y: Fp3<P::Fp3Config>,
21    pub x_over_twist: Fp3<P::Fp3Config>,
22    pub y_over_twist: Fp3<P::Fp3Config>,
23    pub double_coefficients: Vec<AteDoubleCoefficients<P>>,
24    pub addition_coefficients: Vec<AteAdditionCoefficients<P>>,
25}
26
27impl<P: MNT6Config> Default for G2Prepared<P> {
28    fn default() -> Self {
29        Self::from(G2Affine::<P>::generator())
30    }
31}
32
33impl<P: MNT6Config> From<G2Affine<P>> for G2Prepared<P> {
34    fn from(g: G2Affine<P>) -> Self {
35        let twist_inv = P::TWIST.inverse().unwrap();
36
37        let mut g_prep = G2Prepared {
38            x: g.x,
39            y: g.y,
40            x_over_twist: g.x * &twist_inv,
41            y_over_twist: g.y * &twist_inv,
42            double_coefficients: vec![],
43            addition_coefficients: vec![],
44        };
45
46        let mut r = G2ProjectiveExtended {
47            x: g.x,
48            y: g.y,
49            z: <Fp3<P::Fp3Config>>::one(),
50            t: <Fp3<P::Fp3Config>>::one(),
51        };
52
53        let neg_g = g.neg();
54        for bit in P::ATE_LOOP_COUNT.iter().skip(1) {
55            let (r2, coeff) = MNT6::<P>::doubling_for_flipped_miller_loop(&r);
56            g_prep.double_coefficients.push(coeff);
57            r = r2;
58
59            let (r_temp, add_coeff) = match bit {
60                1 => MNT6::<P>::mixed_addition_for_flipper_miller_loop(&g.x, &g.y, &r),
61                -1 => MNT6::<P>::mixed_addition_for_flipper_miller_loop(&neg_g.x, &neg_g.y, &r),
62                0 => continue,
63                _ => unreachable!(),
64            };
65            g_prep.addition_coefficients.push(add_coeff);
66            r = r_temp;
67        }
68
69        if P::ATE_IS_LOOP_COUNT_NEG {
70            let rz_inv = r.z.inverse().unwrap();
71            let rz2_inv = rz_inv.square();
72            let rz3_inv = rz_inv * &rz2_inv;
73
74            let minus_r_x = r.x * &rz2_inv;
75            let minus_r_y = -r.y * &rz3_inv;
76
77            let add_result =
78                MNT6::<P>::mixed_addition_for_flipper_miller_loop(&minus_r_x, &minus_r_y, &r);
79            g_prep.addition_coefficients.push(add_result.1);
80        }
81
82        g_prep
83    }
84}
85
86impl<'a, P: MNT6Config> From<&'a G2Affine<P>> for G2Prepared<P> {
87    fn from(g2: &'a G2Affine<P>) -> Self {
88        (*g2).into()
89    }
90}
91
92impl<P: MNT6Config> From<G2Projective<P>> for G2Prepared<P> {
93    fn from(g2: G2Projective<P>) -> Self {
94        g2.into_affine().into()
95    }
96}
97impl<'a, P: MNT6Config> From<&'a G2Projective<P>> for G2Prepared<P> {
98    fn from(g2: &'a G2Projective<P>) -> Self {
99        (*g2).into()
100    }
101}
102
103pub struct G2ProjectiveExtended<P: MNT6Config> {
104    pub x: Fp3<P::Fp3Config>,
105    pub y: Fp3<P::Fp3Config>,
106    pub z: Fp3<P::Fp3Config>,
107    pub t: Fp3<P::Fp3Config>,
108}
109
110#[derive(Educe, CanonicalSerialize, CanonicalDeserialize)]
111#[educe(Clone, Debug, PartialEq, Eq)]
112pub struct AteDoubleCoefficients<P: MNT6Config> {
113    pub c_h: Fp3<P::Fp3Config>,
114    pub c_4c: Fp3<P::Fp3Config>,
115    pub c_j: Fp3<P::Fp3Config>,
116    pub c_l: Fp3<P::Fp3Config>,
117}
118
119#[derive(Educe, CanonicalSerialize, CanonicalDeserialize)]
120#[educe(Clone, Debug, PartialEq, Eq)]
121pub struct AteAdditionCoefficients<P: MNT6Config> {
122    pub c_l1: Fp3<P::Fp3Config>,
123    pub c_rz: Fp3<P::Fp3Config>,
124}
ark_ec/models/mnt6/g2.rs

ark_ec/models/mnt6/
g2.rs
