/**
* return a sqrt root - the routine verifies that the calculation returns the right value - if
* none exists it returns null.
*/
public override ECFieldElement Sqrt()
{
uint[] c = this.x;
if (Nat224.IsZero(c) || Nat224.IsOne(c))
{
return(this);
}
uint[] nc = Nat224.Create();
SecP224R1Field.Negate(c, nc);
uint[] r = Mod.Random(SecP224R1Field.P);
uint[] t = Nat224.Create();
if (!IsSquare(c))
{
return(null);
}
while (!TrySqrt(nc, r, t))
{
SecP224R1Field.AddOne(r, r);
}
SecP224R1Field.Square(t, r);
return(Nat224.Eq(c, r) ? new SecP224R1FieldElement(t) : null);
}
public override ECFieldElement Sqrt()
{
uint[] array = this.x;
if (Nat224.IsZero(array) || Nat224.IsOne(array))
{
return(this);
}
uint[] array2 = Nat224.Create();
SecP224R1Field.Negate(array, array2);
uint[] array3 = Mod.Random(SecP224R1Field.P);
uint[] t = Nat224.Create();
if (!SecP224R1FieldElement.IsSquare(array))
{
return(null);
}
while (!SecP224R1FieldElement.TrySqrt(array2, array3, t))
{
SecP224R1Field.AddOne(array3, array3);
}
SecP224R1Field.Square(t, array3);
if (!Nat224.Eq(array, array3))
{
return(null);
}
return(new SecP224R1FieldElement(t));
}
/**
* return a sqrt root - the routine verifies that the calculation returns the right value - if
* none exists it returns null.
*/
public override ECFieldElement Sqrt()
{
uint[] c = this.x;
if (Nat224.IsZero(c) || Nat224.IsOne(c))
{
return(this);
}
uint[] nc = Nat224.Create();
SecP224R1Field.Negate(c, nc);
uint[] r = Mod.Random(SecP224R1Field.P);
for (;;)
{
uint[] d1 = Nat224.Create();
Nat224.Copy(r, d1);
uint[] e1 = Nat224.Create();
e1[0] = 1;
uint[] f1 = Nat224.Create();
RP(nc, d1, e1, f1);
uint[] d0 = Nat224.Create();
uint[] e0 = Nat224.Create();
for (int k = 1; k < 96; ++k)
{
Nat224.Copy(d1, d0);
Nat224.Copy(e1, e0);
RS(d1, e1, f1);
if (Nat224.IsZero(d1))
{
Mod.Invert(SecP224R1Field.P, e0, f1);
SecP224R1Field.Multiply(f1, d0, f1);
SecP224R1Field.Square(f1, d1);
return(Nat224.Eq(c, d1) ? new SecP224R1FieldElement(f1) : null);
}
}
// Avoid any possible infinite loop due to a bad random number generator
SecP224R1Field.AddOne(r, r);
}
}
public override ECFieldElement Sqrt()
{
uint[] x = this.x;
if (Nat224.IsZero(x) || Nat224.IsOne(x))
{
return(this);
}
uint[] z = Nat224.Create();
SecP224R1Field.Negate(x, z);
uint[] r = Mod.Random(SecP224R1Field.P);
uint[] t = Nat224.Create();
if (!IsSquare(x))
{
return(null);
}
while (!TrySqrt(z, r, t))
{
SecP224R1Field.AddOne(r, r);
}
SecP224R1Field.Square(t, r);
return(!Nat224.Eq(x, r) ? null : new SecP224R1FieldElement(t));
}
public override ECFieldElement AddOne()
{
uint[] z = Nat224.Create();
SecP224R1Field.AddOne(x, z);
return(new SecP224R1FieldElement(z));
}
