/* Optimal R-ate pairing */
public static FP12 ate(ECP2 P, ECP Q)
{
FP2 f = new FP2(new BIG(ROM.CURVE_Fra), new BIG(ROM.CURVE_Frb));
BIG x = new BIG(ROM.CURVE_Bnx);
BIG n = new BIG(x);
ECP2 K = new ECP2();
FP12 lv;
n.pmul(6);
n.dec(2);
n.norm();
P.affine();
Q.affine();
FP Qx = new FP(Q.getx());
FP Qy = new FP(Q.gety());
ECP2 A = new ECP2();
FP12 r = new FP12(1);
A.copy(P);
int nb = n.nbits();
for (int i = nb - 2; i >= 1; i--)
{
lv = line(A, A, Qx, Qy);
r.smul(lv);
if (n.bit(i) == 1)
{
lv = line(A, P, Qx, Qy);
r.smul(lv);
}
r.sqr();
}
lv = line(A, A, Qx, Qy);
r.smul(lv);
/* R-ate fixup */
r.conj();
K.copy(P);
K.frob(f);
A.neg();
lv = line(A, K, Qx, Qy);
r.smul(lv);
K.frob(f);
K.neg();
lv = line(A, K, Qx, Qy);
r.smul(lv);
return(r);
}
/* Multiply P by e in group G1 */
public static ECP G1mul(ECP P, BIG e)
{
ECP R;
if (ROM.USE_GLV)
{
P.affine();
R = new ECP();
R.copy(P);
int i, np, nn;
ECP Q = new ECP();
Q.copy(P);
BIG q = new BIG(ROM.CURVE_Order);
FP cru = new FP(new BIG(ROM.CURVE_Cru));
BIG t = new BIG(0);
BIG[] u = glv(e);
Q.getx().mul(cru);
np = u[0].nbits();
t.copy(BIG.modneg(u[0], q));
nn = t.nbits();
if (nn < np)
{
u[0].copy(t);
R.neg();
}
np = u[1].nbits();
t.copy(BIG.modneg(u[1], q));
nn = t.nbits();
if (nn < np)
{
u[1].copy(t);
Q.neg();
}
R = R.mul2(u[0], Q, u[1]);
}
else
{
R = P.mul(e);
}
return(R);
}
