public override ECPoint Add(ECPoint b)
        {
            if (this.IsInfinity)
                return b;
            if (b.IsInfinity)
                return this;
            if (this == b)
                return Twice();

            ECCurve curve = this.Curve;

            SecP224K1FieldElement X1 = (SecP224K1FieldElement)this.RawXCoord, Y1 = (SecP224K1FieldElement)this.RawYCoord;
            SecP224K1FieldElement X2 = (SecP224K1FieldElement)b.RawXCoord, Y2 = (SecP224K1FieldElement)b.RawYCoord;

            SecP224K1FieldElement Z1 = (SecP224K1FieldElement)this.RawZCoords[0];
            SecP224K1FieldElement Z2 = (SecP224K1FieldElement)b.RawZCoords[0];

            uint c;
            uint[] tt1 = Nat224.CreateExt();
            uint[] t2 = Nat224.Create();
            uint[] t3 = Nat224.Create();
            uint[] t4 = Nat224.Create();

            bool Z1IsOne = Z1.IsOne;
            uint[] U2, S2;
            if (Z1IsOne)
            {
                U2 = X2.x;
                S2 = Y2.x;
            }
            else
            {
                S2 = t3;
                SecP224K1Field.Square(Z1.x, S2);

                U2 = t2;
                SecP224K1Field.Multiply(S2, X2.x, U2);

                SecP224K1Field.Multiply(S2, Z1.x, S2);
                SecP224K1Field.Multiply(S2, Y2.x, S2);
            }

            bool Z2IsOne = Z2.IsOne;
            uint[] U1, S1;
            if (Z2IsOne)
            {
                U1 = X1.x;
                S1 = Y1.x;
            }
            else
            {
                S1 = t4;
                SecP224K1Field.Square(Z2.x, S1);

                U1 = tt1;
                SecP224K1Field.Multiply(S1, X1.x, U1);

                SecP224K1Field.Multiply(S1, Z2.x, S1);
                SecP224K1Field.Multiply(S1, Y1.x, S1);
            }

            uint[] H = Nat224.Create();
            SecP224K1Field.Subtract(U1, U2, H);

            uint[] R = t2;
            SecP224K1Field.Subtract(S1, S2, R);

            // Check if b == this or b == -this
            if (Nat224.IsZero(H))
            {
                if (Nat224.IsZero(R))
                {
                    // this == b, i.e. this must be doubled
                    return this.Twice();
                }

                // this == -b, i.e. the result is the point at infinity
                return curve.Infinity;
            }

            uint[] HSquared = t3;
            SecP224K1Field.Square(H, HSquared);

            uint[] G = Nat224.Create();
            SecP224K1Field.Multiply(HSquared, H, G);

            uint[] V = t3;
            SecP224K1Field.Multiply(HSquared, U1, V);

            SecP224K1Field.Negate(G, G);
            Nat224.Mul(S1, G, tt1);

            c = Nat224.AddBothTo(V, V, G);
            SecP224K1Field.Reduce32(c, G);

            SecP224K1FieldElement X3 = new SecP224K1FieldElement(t4);
            SecP224K1Field.Square(R, X3.x);
            SecP224K1Field.Subtract(X3.x, G, X3.x);

            SecP224K1FieldElement Y3 = new SecP224K1FieldElement(G);
            SecP224K1Field.Subtract(V, X3.x, Y3.x);
            SecP224K1Field.MultiplyAddToExt(Y3.x, R, tt1);
            SecP224K1Field.Reduce(tt1, Y3.x);

            SecP224K1FieldElement Z3 = new SecP224K1FieldElement(H);
            if (!Z1IsOne)
            {
                SecP224K1Field.Multiply(Z3.x, Z1.x, Z3.x);
            }
            if (!Z2IsOne)
            {
                SecP224K1Field.Multiply(Z3.x, Z2.x, Z3.x);
            }

            ECFieldElement[] zs = new ECFieldElement[] { Z3 };

            return new SecP224K1Point(curve, X3, Y3, zs, IsCompressed);
        }
        public override ECPoint Twice()
        {
            if (this.IsInfinity)
                return this;

            ECCurve curve = this.Curve;

            SecP224K1FieldElement Y1 = (SecP224K1FieldElement)this.RawYCoord;
            if (Y1.IsZero)
                return curve.Infinity;

            SecP224K1FieldElement X1 = (SecP224K1FieldElement)this.RawXCoord, Z1 = (SecP224K1FieldElement)this.RawZCoords[0];

            uint c;

            uint[] Y1Squared = Nat224.Create();
            SecP224K1Field.Square(Y1.x, Y1Squared);

            uint[] T = Nat224.Create();
            SecP224K1Field.Square(Y1Squared, T);

            uint[] M = Nat224.Create();
            SecP224K1Field.Square(X1.x, M);
            c = Nat224.AddBothTo(M, M, M);
            SecP224K1Field.Reduce32(c, M);

            uint[] S = Y1Squared;
            SecP224K1Field.Multiply(Y1Squared, X1.x, S);
            c = Nat.ShiftUpBits(7, S, 2, 0);
            SecP224K1Field.Reduce32(c, S);

            uint[] t1 = Nat224.Create();
            c = Nat.ShiftUpBits(7, T, 3, 0, t1);
            SecP224K1Field.Reduce32(c, t1);

            SecP224K1FieldElement X3 = new SecP224K1FieldElement(T);
            SecP224K1Field.Square(M, X3.x);
            SecP224K1Field.Subtract(X3.x, S, X3.x);
            SecP224K1Field.Subtract(X3.x, S, X3.x);

            SecP224K1FieldElement Y3 = new SecP224K1FieldElement(S);
            SecP224K1Field.Subtract(S, X3.x, Y3.x);
            SecP224K1Field.Multiply(Y3.x, M, Y3.x);
            SecP224K1Field.Subtract(Y3.x, t1, Y3.x);

            SecP224K1FieldElement Z3 = new SecP224K1FieldElement(M);
            SecP224K1Field.Twice(Y1.x, Z3.x);
            if (!Z1.IsOne)
            {
                SecP224K1Field.Multiply(Z3.x, Z1.x, Z3.x);
            }

            return new SecP224K1Point(curve, X3, Y3, new ECFieldElement[] { Z3 }, IsCompressed);
        }
 public virtual bool Equals(SecP224K1FieldElement other)
 {
     if (this == other)
         return true;
     if (null == other)
         return false;
     return Nat224.Eq(x, other.x);
 }
        public override ECPoint Add(ECPoint b)
        {
            if (this.IsInfinity)
            {
                return(b);
            }
            if (b.IsInfinity)
            {
                return(this);
            }
            if (this == b)
            {
                return(Twice());
            }

            ECCurve curve = this.Curve;

            SecP224K1FieldElement X1 = (SecP224K1FieldElement)this.RawXCoord, Y1 = (SecP224K1FieldElement)this.RawYCoord;
            SecP224K1FieldElement X2 = (SecP224K1FieldElement)b.RawXCoord, Y2 = (SecP224K1FieldElement)b.RawYCoord;

            SecP224K1FieldElement Z1 = (SecP224K1FieldElement)this.RawZCoords[0];
            SecP224K1FieldElement Z2 = (SecP224K1FieldElement)b.RawZCoords[0];

            uint c;

            uint[] tt1 = Nat224.CreateExt();
            uint[] t2  = Nat224.Create();
            uint[] t3  = Nat224.Create();
            uint[] t4  = Nat224.Create();

            bool Z1IsOne = Z1.IsOne;

            uint[] U2, S2;
            if (Z1IsOne)
            {
                U2 = X2.x;
                S2 = Y2.x;
            }
            else
            {
                S2 = t3;
                SecP224K1Field.Square(Z1.x, S2);

                U2 = t2;
                SecP224K1Field.Multiply(S2, X2.x, U2);

                SecP224K1Field.Multiply(S2, Z1.x, S2);
                SecP224K1Field.Multiply(S2, Y2.x, S2);
            }

            bool Z2IsOne = Z2.IsOne;

            uint[] U1, S1;
            if (Z2IsOne)
            {
                U1 = X1.x;
                S1 = Y1.x;
            }
            else
            {
                S1 = t4;
                SecP224K1Field.Square(Z2.x, S1);

                U1 = tt1;
                SecP224K1Field.Multiply(S1, X1.x, U1);

                SecP224K1Field.Multiply(S1, Z2.x, S1);
                SecP224K1Field.Multiply(S1, Y1.x, S1);
            }

            uint[] H = Nat224.Create();
            SecP224K1Field.Subtract(U1, U2, H);

            uint[] R = t2;
            SecP224K1Field.Subtract(S1, S2, R);

            // Check if b == this or b == -this
            if (Nat224.IsZero(H))
            {
                if (Nat224.IsZero(R))
                {
                    // this == b, i.e. this must be doubled
                    return(this.Twice());
                }

                // this == -b, i.e. the result is the point at infinity
                return(curve.Infinity);
            }

            uint[] HSquared = t3;
            SecP224K1Field.Square(H, HSquared);

            uint[] G = Nat224.Create();
            SecP224K1Field.Multiply(HSquared, H, G);

            uint[] V = t3;
            SecP224K1Field.Multiply(HSquared, U1, V);

            SecP224K1Field.Negate(G, G);
            Nat224.Mul(S1, G, tt1);

            c = Nat224.AddBothTo(V, V, G);
            SecP224K1Field.Reduce32(c, G);

            SecP224K1FieldElement X3 = new SecP224K1FieldElement(t4);

            SecP224K1Field.Square(R, X3.x);
            SecP224K1Field.Subtract(X3.x, G, X3.x);

            SecP224K1FieldElement Y3 = new SecP224K1FieldElement(G);

            SecP224K1Field.Subtract(V, X3.x, Y3.x);
            SecP224K1Field.MultiplyAddToExt(Y3.x, R, tt1);
            SecP224K1Field.Reduce(tt1, Y3.x);

            SecP224K1FieldElement Z3 = new SecP224K1FieldElement(H);

            if (!Z1IsOne)
            {
                SecP224K1Field.Multiply(Z3.x, Z1.x, Z3.x);
            }
            if (!Z2IsOne)
            {
                SecP224K1Field.Multiply(Z3.x, Z2.x, Z3.x);
            }

            ECFieldElement[] zs = new ECFieldElement[] { Z3 };

            return(new SecP224K1Point(curve, X3, Y3, zs, IsCompressed));
        }
        public override ECPoint Twice()
        {
            if (this.IsInfinity)
            {
                return(this);
            }

            ECCurve curve = this.Curve;

            SecP224K1FieldElement Y1 = (SecP224K1FieldElement)this.RawYCoord;

            if (Y1.IsZero)
            {
                return(curve.Infinity);
            }

            SecP224K1FieldElement X1 = (SecP224K1FieldElement)this.RawXCoord, Z1 = (SecP224K1FieldElement)this.RawZCoords[0];

            uint c;

            uint[] Y1Squared = Nat224.Create();
            SecP224K1Field.Square(Y1.x, Y1Squared);

            uint[] T = Nat224.Create();
            SecP224K1Field.Square(Y1Squared, T);

            uint[] M = Nat224.Create();
            SecP224K1Field.Square(X1.x, M);
            c = Nat224.AddBothTo(M, M, M);
            SecP224K1Field.Reduce32(c, M);

            uint[] S = Y1Squared;
            SecP224K1Field.Multiply(Y1Squared, X1.x, S);
            c = Nat.ShiftUpBits(7, S, 2, 0);
            SecP224K1Field.Reduce32(c, S);

            uint[] t1 = Nat224.Create();
            c = Nat.ShiftUpBits(7, T, 3, 0, t1);
            SecP224K1Field.Reduce32(c, t1);

            SecP224K1FieldElement X3 = new SecP224K1FieldElement(T);

            SecP224K1Field.Square(M, X3.x);
            SecP224K1Field.Subtract(X3.x, S, X3.x);
            SecP224K1Field.Subtract(X3.x, S, X3.x);

            SecP224K1FieldElement Y3 = new SecP224K1FieldElement(S);

            SecP224K1Field.Subtract(S, X3.x, Y3.x);
            SecP224K1Field.Multiply(Y3.x, M, Y3.x);
            SecP224K1Field.Subtract(Y3.x, t1, Y3.x);

            SecP224K1FieldElement Z3 = new SecP224K1FieldElement(M);

            SecP224K1Field.Twice(Y1.x, Z3.x);
            if (!Z1.IsOne)
            {
                SecP224K1Field.Multiply(Z3.x, Z1.x, Z3.x);
            }

            return(new SecP224K1Point(curve, X3, Y3, new ECFieldElement[] { Z3 }, IsCompressed));
        }
        public override ECPoint Add(ECPoint b)
        {
            if (base.IsInfinity)
            {
                return(b);
            }
            if (b.IsInfinity)
            {
                return(this);
            }
            if (this == b)
            {
                return(Twice());
            }
            ECCurve curve = Curve;
            SecP224K1FieldElement secP224K1FieldElement  = (SecP224K1FieldElement)base.RawXCoord;
            SecP224K1FieldElement secP224K1FieldElement2 = (SecP224K1FieldElement)base.RawYCoord;
            SecP224K1FieldElement secP224K1FieldElement3 = (SecP224K1FieldElement)b.RawXCoord;
            SecP224K1FieldElement secP224K1FieldElement4 = (SecP224K1FieldElement)b.RawYCoord;
            SecP224K1FieldElement secP224K1FieldElement5 = (SecP224K1FieldElement)base.RawZCoords[0];
            SecP224K1FieldElement secP224K1FieldElement6 = (SecP224K1FieldElement)b.RawZCoords[0];

            uint[] array  = Nat224.CreateExt();
            uint[] array2 = Nat224.Create();
            uint[] array3 = Nat224.Create();
            uint[] array4 = Nat224.Create();
            bool   isOne  = secP224K1FieldElement5.IsOne;

            uint[] array5;
            uint[] array6;
            if (isOne)
            {
                array5 = secP224K1FieldElement3.x;
                array6 = secP224K1FieldElement4.x;
            }
            else
            {
                array6 = array3;
                SecP224K1Field.Square(secP224K1FieldElement5.x, array6);
                array5 = array2;
                SecP224K1Field.Multiply(array6, secP224K1FieldElement3.x, array5);
                SecP224K1Field.Multiply(array6, secP224K1FieldElement5.x, array6);
                SecP224K1Field.Multiply(array6, secP224K1FieldElement4.x, array6);
            }
            bool isOne2 = secP224K1FieldElement6.IsOne;

            uint[] array7;
            uint[] array8;
            if (isOne2)
            {
                array7 = secP224K1FieldElement.x;
                array8 = secP224K1FieldElement2.x;
            }
            else
            {
                array8 = array4;
                SecP224K1Field.Square(secP224K1FieldElement6.x, array8);
                array7 = array;
                SecP224K1Field.Multiply(array8, secP224K1FieldElement.x, array7);
                SecP224K1Field.Multiply(array8, secP224K1FieldElement6.x, array8);
                SecP224K1Field.Multiply(array8, secP224K1FieldElement2.x, array8);
            }
            uint[] array9 = Nat224.Create();
            SecP224K1Field.Subtract(array7, array5, array9);
            uint[] array10 = array2;
            SecP224K1Field.Subtract(array8, array6, array10);
            if (Nat224.IsZero(array9))
            {
                if (Nat224.IsZero(array10))
                {
                    return(Twice());
                }
                return(curve.Infinity);
            }
            uint[] array11 = array3;
            SecP224K1Field.Square(array9, array11);
            uint[] array12 = Nat224.Create();
            SecP224K1Field.Multiply(array11, array9, array12);
            uint[] array13 = array3;
            SecP224K1Field.Multiply(array11, array7, array13);
            SecP224K1Field.Negate(array12, array12);
            Nat224.Mul(array8, array12, array);
            uint x = Nat224.AddBothTo(array13, array13, array12);

            SecP224K1Field.Reduce32(x, array12);
            SecP224K1FieldElement secP224K1FieldElement7 = new SecP224K1FieldElement(array4);

            SecP224K1Field.Square(array10, secP224K1FieldElement7.x);
            SecP224K1Field.Subtract(secP224K1FieldElement7.x, array12, secP224K1FieldElement7.x);
            SecP224K1FieldElement secP224K1FieldElement8 = new SecP224K1FieldElement(array12);

            SecP224K1Field.Subtract(array13, secP224K1FieldElement7.x, secP224K1FieldElement8.x);
            SecP224K1Field.MultiplyAddToExt(secP224K1FieldElement8.x, array10, array);
            SecP224K1Field.Reduce(array, secP224K1FieldElement8.x);
            SecP224K1FieldElement secP224K1FieldElement9 = new SecP224K1FieldElement(array9);

            if (!isOne)
            {
                SecP224K1Field.Multiply(secP224K1FieldElement9.x, secP224K1FieldElement5.x, secP224K1FieldElement9.x);
            }
            if (!isOne2)
            {
                SecP224K1Field.Multiply(secP224K1FieldElement9.x, secP224K1FieldElement6.x, secP224K1FieldElement9.x);
            }
            ECFieldElement[] zs = new ECFieldElement[1] {
                secP224K1FieldElement9
            };
            return(new SecP224K1Point(curve, secP224K1FieldElement7, secP224K1FieldElement8, zs, base.IsCompressed));
        }