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crypto: Use the generic ecc::dbl for G2 point doubling #1635

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Merged
chfast merged 1 commit into from
Aug 10, 2026
Merged

crypto: Use the generic ecc::dbl for G2 point doubling #1635

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2 changes: 1 addition & 1 deletion lib/evmone_precompiles/ecc.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -371,7 +371,7 @@ ProjPoint<Curve> add(const ProjPoint<Curve>& p, const AffinePoint<Curve>& q) noe
}

template <typename Curve>
ProjPoint<Curve> dbl(const ProjPoint<Curve>& p) noexcept
constexpr ProjPoint<Curve> dbl(const ProjPoint<Curve>& p) noexcept
{
const auto& [x1, y1, z1] = p;

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27 changes: 0 additions & 27 deletions lib/evmone_precompiles/pairing/bn254/utils.hpp
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Expand Up @@ -192,33 +192,6 @@ constexpr ecc::ProjPoint<E2> add(
return {X3, Y3, Z3};
}

/// Computes `Q + Q` in Jacobian coordinates.
constexpr ecc::ProjPoint<E2> dbl(const ecc::ProjPoint<E2>& Q) noexcept
{
const auto& x = Q.x;
const auto& y = Q.y;
const auto& z = Q.z;

const auto y_squared = y * y;
const auto x_squared = x * x;
const auto z_squared = z * z;
const auto y_4 = y_squared * y_squared;
const auto _4y_4 = y_4 + y_4 + y_4 + y_4;

const auto R = y_squared + y_squared;
const auto A = (x + R);
const auto S = A * A - x_squared - _4y_4; // 2xR = (x+R)^2 - x^2 - R^2
const auto M = x_squared + x_squared + x_squared;

const auto N = y + z;

const auto Xp = M * M - (S + S);
const auto Yp = M * (S - Xp) - (_4y_4 + _4y_4);
const auto Zp = N * N - y_squared - z_squared; // 2yz = (y+z)^2 - y^2 - z^2

return {Xp, Yp, Zp};
}

/// Computes `N` doubles of the point `a` in Jacobian coordinates.
template <int N>
constexpr ecc::ProjPoint<E2> n_dbl(const ecc::ProjPoint<E2>& a) noexcept
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