| public static GetMu ( F2mCurve curve ) : sbyte | ||
| curve | F2mCurve | |
| return | sbyte | |
public static BigInteger[] GetSi(AbstractF2mCurve curve)
{
if (!curve.IsKoblitz)
{
throw new ArgumentException("si is defined for Koblitz curves only");
}
int fieldSize = curve.FieldSize;
int intValue = curve.A.ToBigInteger().IntValue;
sbyte mu = Tnaf.GetMu(intValue);
int shiftsForCofactor = Tnaf.GetShiftsForCofactor(curve.Cofactor);
int k = fieldSize + 3 - intValue;
BigInteger[] lucas = Tnaf.GetLucas(mu, k, false);
if (mu == 1)
{
lucas[0] = lucas[0].Negate();
lucas[1] = lucas[1].Negate();
}
BigInteger bigInteger = BigInteger.One.Add(lucas[1]).ShiftRight(shiftsForCofactor);
BigInteger bigInteger2 = BigInteger.One.Add(lucas[0]).ShiftRight(shiftsForCofactor).Negate();
return(new BigInteger[]
{
bigInteger,
bigInteger2
});
}
public static AbstractF2mPoint MultiplyTnaf(AbstractF2mPoint p, ZTauElement lambda)
{
AbstractF2mCurve abstractF2mCurve = (AbstractF2mCurve)p.Curve;
sbyte mu = Tnaf.GetMu(abstractF2mCurve.A);
sbyte[] u = Tnaf.TauAdicNaf(mu, lambda);
return(Tnaf.MultiplyFromTnaf(p, u));
}
public static AbstractF2mPoint MultiplyRTnaf(AbstractF2mPoint p, BigInteger k)
{
AbstractF2mCurve abstractF2mCurve = (AbstractF2mCurve)p.Curve;
int fieldSize = abstractF2mCurve.FieldSize;
int intValue = abstractF2mCurve.A.ToBigInteger().IntValue;
sbyte mu = Tnaf.GetMu(intValue);
BigInteger[] si = abstractF2mCurve.GetSi();
ZTauElement lambda = Tnaf.PartModReduction(k, fieldSize, (sbyte)intValue, si, mu, 10);
return(Tnaf.MultiplyTnaf(p, lambda));
}
public static BigInteger[] GetSi(int fieldSize, int curveA, BigInteger cofactor)
{
sbyte mu = Tnaf.GetMu(curveA);
int shiftsForCofactor = Tnaf.GetShiftsForCofactor(cofactor);
int k = fieldSize + 3 - curveA;
BigInteger[] lucas = Tnaf.GetLucas(mu, k, false);
if (mu == 1)
{
lucas[0] = lucas[0].Negate();
lucas[1] = lucas[1].Negate();
}
BigInteger bigInteger = BigInteger.One.Add(lucas[1]).ShiftRight(shiftsForCofactor);
BigInteger bigInteger2 = BigInteger.One.Add(lucas[0]).ShiftRight(shiftsForCofactor).Negate();
return(new BigInteger[]
{
bigInteger,
bigInteger2
});
}
