1use crate::fields::{cubic_extension::*, fp2::*};
 2use algebra::fields::{fp6_3over2::*, CubicExtParameters, Fp2};
 3use core::ops::MulAssign;
 4use r1cs_core::SynthesisError;
 5
 6pub type Fp6Var<P> = CubicExtVar<Fp2Var<<P as Fp6Parameters>::Fp2Params>, Fp6ParamsWrapper<P>>;
 7
 8impl<P: Fp6Parameters> CubicExtVarParams<Fp2Var<P::Fp2Params>> for Fp6ParamsWrapper<P> {
 9    fn mul_base_field_vars_by_frob_coeff(
10        c1: &mut Fp2Var<P::Fp2Params>,
11        c2: &mut Fp2Var<P::Fp2Params>,
12        power: usize,
13    ) {
14        *c1 *= Self::FROBENIUS_COEFF_C1[power % Self::DEGREE_OVER_BASE_PRIME_FIELD];
15        *c2 *= Self::FROBENIUS_COEFF_C2[power % Self::DEGREE_OVER_BASE_PRIME_FIELD];
16    }
17}
18
19impl<P: Fp6Parameters> Fp6Var<P> {
20    pub fn mul_by_0_c1_0(&self, c1: &Fp2Var<P::Fp2Params>) -> Result<Self, SynthesisError> {
21        // Karatsuba multiplication
22        // v0 = a0 * b0 = 0
23
24        // v1 = a1 * b1
25        let v1 = &self.c1 * c1;
26
27        // v2 = a2 * b2 = 0
28
29        let a1_plus_a2 = &self.c1 + &self.c2;
30        let b1_plus_b2 = c1.clone();
31
32        let a0_plus_a1 = &self.c0 + &self.c1;
33
34        // c0 = (NONRESIDUE * ((a1 + a2)*(b1 + b2) - v1 - v2)) + v0
35        //    = NONRESIDUE * ((a1 + a2) * b1 - v1)
36        let c0 = &(a1_plus_a2 * &b1_plus_b2 - &v1) * P::NONRESIDUE;
37
38        // c1 = (a0 + a1) * (b0 + b1) - v0 - v1 + NONRESIDUE * v2
39        //    = (a0 + a1) * b1 - v1
40        let c1 = a0_plus_a1 * c1 - &v1;
41        // c2 = (a0 + a2) * (b0 + b2) - v0 - v2 + v1
42        //    = v1
43        let c2 = v1;
44        Ok(Self::new(c0, c1, c2))
45    }
46
47    // #[inline]
48    pub fn mul_by_c0_c1_0(
49        &self,
50        c0: &Fp2Var<P::Fp2Params>,
51        c1: &Fp2Var<P::Fp2Params>,
52    ) -> Result<Self, SynthesisError> {
53        let v0 = &self.c0 * c0;
54        let v1 = &self.c1 * c1;
55        // v2 = 0.
56
57        let a1_plus_a2 = &self.c1 + &self.c2;
58        let a0_plus_a1 = &self.c0 + &self.c1;
59        let a0_plus_a2 = &self.c0 + &self.c2;
60
61        let b1_plus_b2 = c1.clone();
62        let b0_plus_b1 = c0 + c1;
63        let b0_plus_b2 = c0.clone();
64
65        let c0 = (&a1_plus_a2 * &b1_plus_b2 - &v1) * P::NONRESIDUE + &v0;
66
67        let c1 = a0_plus_a1 * &b0_plus_b1 - &v0 - &v1;
68
69        let c2 = a0_plus_a2 * &b0_plus_b2 - &v0 + &v1;
70
71        Ok(Self::new(c0, c1, c2))
72    }
73}
74
75impl<P: Fp6Parameters> MulAssign<Fp2<P::Fp2Params>> for Fp6Var<P> {
76    fn mul_assign(&mut self, other: Fp2<P::Fp2Params>) {
77        self.c0 *= other;
78        self.c1 *= other;
79        self.c2 *= other;
80    }
81}