multiplication by integer

This commit is contained in:
orignal 2015-04-08 13:49:27 -04:00
parent 75d45ae988
commit 8c92c50f9a

View file

@ -20,7 +20,7 @@ namespace crypto
private: private:
CryptoPP::ECP::Point Sum (CryptoPP::ECP::Point p1, CryptoPP::ECP::Point p2) CryptoPP::ECP::Point Sum (const CryptoPP::ECP::Point& p1, const CryptoPP::ECP::Point& p2)
{ {
CryptoPP::Integer m = d*p1.x*p2.x*p1.y*p2.y, CryptoPP::Integer m = d*p1.x*p2.x*p1.y*p2.y,
x = a_times_b_mod_c (p1.x*p2.y + p2.x*p1.y, (CryptoPP::Integer::One() + m).InverseMod (q), q), x = a_times_b_mod_c (p1.x*p2.y + p2.x*p1.y, (CryptoPP::Integer::One() + m).InverseMod (q), q),
@ -28,10 +28,19 @@ namespace crypto
return CryptoPP::ECP::Point {x, y}; return CryptoPP::ECP::Point {x, y};
} }
CryptoPP::ECP::Point Mul (CryptoPP::ECP::Point p, CryptoPP::Integer e) CryptoPP::ECP::Point Mul (const CryptoPP::ECP::Point& p, const CryptoPP::Integer& e)
{ {
if (e.IsZero ()) return CryptoPP::ECP::Point {0, 1}; CryptoPP::ECP::Point res {0, 1};
return p; // TODO if (!e.IsZero ())
{
auto bitCount = e.BitCount ();
for (int i = bitCount - 1; i >= 0; i--)
{
res = Sum (res, res);
if (e.GetBit (i)) res = Sum (res, p);
}
}
return res;
} }
private: private: