bls12_381_g2.hpp

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#ifndef BLS12_381_G2_HPP_
#define BLS12_381_G2_HPP_
#include <libff/algebra/curves/bls12_381/bls12_381_init.hpp>
#include <libff/algebra/curves/curve_utils.hpp>
#include <vector>
 
namespace libff
{
 
class bls12_381_G2;
std::ostream &operator<<(std::ostream &, const bls12_381_G2 &);
std::istream &operator>>(std::istream &, bls12_381_G2 &);
 
class bls12_381_G2
{
public:
#ifdef PROFILE_OP_COUNTS
    static long long add_cnt;
    static long long dbl_cnt;
#endif
    static std::vector<std::size_t> wnaf_window_table;
    static std::vector<std::size_t> fixed_base_exp_window_table;
    static bls12_381_G2 G2_zero;
    static bls12_381_G2 G2_one;
    static bls12_381_Fq2 coeff_a;
    static bls12_381_Fq2 coeff_b;
 
    typedef bls12_381_Fq base_field;
    typedef bls12_381_Fq2 twist_field;
    typedef bls12_381_Fr scalar_field;
 
    // Cofactor
    static const mp_size_t h_bitcount = 507;
    static const mp_size_t h_limbs =
        (h_bitcount + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS;
    static bigint<h_limbs> h;
 
    bls12_381_Fq2 X, Y, Z;
 
    // using Jacobian coordinates
    bls12_381_G2();
    bls12_381_G2(
        const bls12_381_Fq2 &X, const bls12_381_Fq2 &Y, const bls12_381_Fq2 &Z)
        : X(X), Y(Y), Z(Z){};
 
    static bls12_381_Fq2 mul_by_b(const bls12_381_Fq2 &elt);
 
    void print() const;
    void print_coordinates() const;
 
    void to_affine_coordinates();
    void to_special();
    bool is_special() const;
 
    bool is_zero() const;
 
    bool operator==(const bls12_381_G2 &other) const;
    bool operator!=(const bls12_381_G2 &other) const;
 
    bls12_381_G2 operator+(const bls12_381_G2 &other) const;
    bls12_381_G2 operator-() const;
    bls12_381_G2 operator-(const bls12_381_G2 &other) const;
 
    bls12_381_G2 add(const bls12_381_G2 &other) const;
    bls12_381_G2 mixed_add(const bls12_381_G2 &other) const;
    bls12_381_G2 dbl() const;
    bls12_381_G2 mul_by_q() const;
    bls12_381_G2 mul_by_cofactor() const;
 
    bool is_well_formed() const;
    bool is_in_safe_subgroup() const;
 
    static const bls12_381_G2 &zero();
    static const bls12_381_G2 &one();
    static bls12_381_G2 random_element();
 
    static std::size_t size_in_bits()
    {
        return twist_field::size_in_bits() + 1;
    }
    static bigint<base_field::num_limbs> base_field_char()
    {
        return base_field::field_char();
    }
    static bigint<scalar_field::num_limbs> order()
    {
        return scalar_field::field_char();
    }
 
    void write_uncompressed(std::ostream &) const;
    void write_compressed(std::ostream &) const;
    static void read_uncompressed(std::istream &, bls12_381_G2 &);
    static void read_compressed(std::istream &, bls12_381_G2 &);
 
    static void batch_to_special_all_non_zeros(std::vector<bls12_381_G2> &vec);
};
 
template<mp_size_t m>
bls12_381_G2 operator*(const bigint<m> &lhs, const bls12_381_G2 &rhs)
{
    return scalar_mul<bls12_381_G2, m>(rhs, lhs);
}
 
template<mp_size_t m, const bigint<m> &modulus_p>
bls12_381_G2 operator*(
    const Fp_model<m, modulus_p> &lhs, const bls12_381_G2 &rhs)
{
    return scalar_mul<bls12_381_G2, m>(rhs, lhs.as_bigint());
}
 
} // namespace libff
 
#endif // BLS12_381_G2_HPP_