GetEndomorphism() public method

public GetEndomorphism ( ) : ECEndomorphism
return ECEndomorphism
Esempio n. 1
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        public static ECPoint SumOfTwoMultiplies(ECPoint P, BigInteger a, ECPoint Q, BigInteger b)
        {
            ECCurve cp = P.Curve;

            Q = ImportPoint(cp, Q);

            // Point multiplication for Koblitz curves (using WTNAF) beats Shamir's trick
            {
                var f2mCurve = cp as AbstractF2mCurve;
                if (f2mCurve != null && f2mCurve.IsKoblitz)
                {
                    return(ValidatePoint(P.Multiply(a).Add(Q.Multiply(b))));
                }
            }

            var glvEndomorphism = cp.GetEndomorphism() as GlvEndomorphism;

            if (glvEndomorphism != null)
            {
                return(ValidatePoint(
                           ImplSumOfMultipliesGlv(new ECPoint[] { P, Q }, new BigInteger[] { a, b }, glvEndomorphism)));
            }

            return(ValidatePoint(ImplShamirsTrickWNaf(P, a, Q, b)));
        }
Esempio n. 2
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        public static ECPoint SumOfMultiplies(ECPoint[] ps, BigInteger[] ks)
        {
            if (ps == null || ks == null || ps.Length != ks.Length || ps.Length < 1)
            {
                throw new ArgumentException("point and scalar arrays should be non-null, and of equal, non-zero, length");
            }

            int count = ps.Length;

            switch (count)
            {
            case 1:
                return(ps[0].Multiply(ks[0]));

            case 2:
                return(SumOfTwoMultiplies(ps[0], ks[0], ps[1], ks[1]));

            default:
                break;
            }

            ECPoint p = ps[0];
            ECCurve c = p.Curve;

            var imported = new ECPoint[count];

            imported[0] = p;
            for (int i = 1; i < count; ++i)
            {
                imported[i] = ImportPoint(c, ps[i]);
            }

            var glvEndomorphism = c.GetEndomorphism() as GlvEndomorphism;

            if (glvEndomorphism != null)
            {
                return(ValidatePoint(ImplSumOfMultipliesGlv(imported, ks, glvEndomorphism)));
            }

            return(ValidatePoint(ImplSumOfMultiplies(imported, ks)));
        }