private int Window(BigInt x, int i, int[] nbs, int[] nzs, int w)
{
// TODO Auto-generated method stub
int j, r;
nbs[0] = 1;
nzs[0] = 0;
sbyte[] xa = x.ToByteArray();
//check for leading 0 bit
if (!ByteArrayUtil.GetBitByDegree(i, xa))
{
return(0);
}
//adjust window if not enough bits left
if (i - w + 1 < 0)
{
w = i + 1;
}
r = 1;
for (j = i - 1; j > i - w; j--)
{
nbs[0]++;
r *= 2;
if (ByteArrayUtil.GetBitByDegree(j, xa))
{
r += 1;
}
if (r % 4 == 0)
{
r /= 4;
nbs[0] -= 2;
nzs[0] = 2;
break;
}
}
if (r % 2 == 0)
{
r /= 2;
nzs[0] = 1;
nbs[0]--;
}
return(r);
}
private Point SimpleMultiply(Point p, BigInt k)
{
if (!(this.field.IsValidElement(p.X)) || !(this.field.IsValidElement(p.Y))
)
{
throw new ArgumentException("The input point must be taken over the field.");
}
if (p.IsInfinity())
{
return(p);
}
if (k.Equals(BigInt.ZERO))
{
return(Point.INFINITY);
}
if (k.Equals(BigInt.ONE))
{
return(p);
}
if (k.Signum() == -1)
{
k = k.Abs();
p = this.Negate(p);
}
sbyte[] ba = k.ToByteArray();
int degree = ByteArrayUtil.DegreeOf(ba) - 1;
Point x = p;
for (int i = degree; i >= 0; i--)
{
x = this.Dbl(x);
if (ByteArrayUtil.GetBitByDegree(i, ba))
{
x = this.Add(p, x);
}
}
return(x);
}