alt_bn128_g2.hpp

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#ifndef ALT_BN128_G2_HPP_
#define ALT_BN128_G2_HPP_
#include <libff/algebra/curves/alt_bn128/alt_bn128_init.hpp>
#include <libff/algebra/curves/curve_utils.hpp>
#include <vector>
 
namespace libff
{
 
class alt_bn128_G2;
std::ostream &operator<<(std::ostream &, const alt_bn128_G2 &);
std::istream &operator>>(std::istream &, alt_bn128_G2 &);
 
class alt_bn128_G2
{
public:
#ifdef PROFILE_OP_COUNTS
    static long long add_cnt;
    static long long dbl_cnt;
#endif
    static std::vector<size_t> wnaf_window_table;
    static std::vector<size_t> fixed_base_exp_window_table;
    static alt_bn128_G2 G2_zero;
    static alt_bn128_G2 G2_one;
    static alt_bn128_Fq2 coeff_a;
    static alt_bn128_Fq2 coeff_b;
 
    typedef alt_bn128_Fq base_field;
    typedef alt_bn128_Fq2 twist_field;
    typedef alt_bn128_Fr scalar_field;
 
    // Cofactor
    static const mp_size_t h_bitcount = 256;
    static const mp_size_t h_limbs =
        (h_bitcount + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS;
    static bigint<h_limbs> h;
 
    alt_bn128_Fq2 X, Y, Z;
 
    // using Jacobian coordinates
    alt_bn128_G2();
    alt_bn128_G2(
        const alt_bn128_Fq2 &X, const alt_bn128_Fq2 &Y, const alt_bn128_Fq2 &Z)
        : X(X), Y(Y), Z(Z){};
 
    static alt_bn128_Fq2 mul_by_b(const alt_bn128_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 alt_bn128_G2 &other) const;
    bool operator!=(const alt_bn128_G2 &other) const;
 
    alt_bn128_G2 operator+(const alt_bn128_G2 &other) const;
    alt_bn128_G2 operator-() const;
    alt_bn128_G2 operator-(const alt_bn128_G2 &other) const;
 
    alt_bn128_G2 add(const alt_bn128_G2 &other) const;
    alt_bn128_G2 mixed_add(const alt_bn128_G2 &other) const;
    alt_bn128_G2 dbl() const;
    alt_bn128_G2 mul_by_q() const;
    alt_bn128_G2 mul_by_cofactor() const;
 
    bool is_well_formed() const;
    bool is_in_safe_subgroup() const;
 
    static const alt_bn128_G2 &zero();
    static const alt_bn128_G2 &one();
    static alt_bn128_G2 random_element();
 
    static 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 &, alt_bn128_G2 &);
    static void read_compressed(std::istream &, alt_bn128_G2 &);
 
    static void batch_to_special_all_non_zeros(std::vector<alt_bn128_G2> &vec);
};
 
template<mp_size_t m>
alt_bn128_G2 operator*(const bigint<m> &lhs, const alt_bn128_G2 &rhs)
{
    return scalar_mul<alt_bn128_G2, m>(rhs, lhs);
}
 
template<mp_size_t m, const bigint<m> &modulus_p>
alt_bn128_G2 operator*(
    const Fp_model<m, modulus_p> &lhs, const alt_bn128_G2 &rhs)
{
    return scalar_mul<alt_bn128_G2, m>(rhs, lhs.as_bigint());
}
 
} // namespace libff
#endif // ALT_BN128_G2_HPP_