diff --git a/crypto/src/math/ec/ECFieldElement.cs b/crypto/src/math/ec/ECFieldElement.cs
index e589fc737..27c4ba2d0 100644
--- a/crypto/src/math/ec/ECFieldElement.cs
+++ b/crypto/src/math/ec/ECFieldElement.cs
@@ -55,6 +55,16 @@ namespace Org.BouncyCastle.Math.EC
return Square().Add(x.Multiply(y));
}
+ public virtual ECFieldElement SquarePow(int pow)
+ {
+ ECFieldElement r = this;
+ for (int i = 0; i < pow; ++i)
+ {
+ r = r.Square();
+ }
+ return r;
+ }
+
public virtual bool TestBitZero()
{
return ToBigInteger().TestBit(0);
@@ -812,6 +822,11 @@ namespace Org.BouncyCastle.Math.EC
return new F2mFieldElement(m, ks, aa);
}
+ public override ECFieldElement SquarePow(int pow)
+ {
+ return pow < 1 ? this : new F2mFieldElement(m, ks, x.ModSquareN(pow, m, ks));
+ }
+
public override ECFieldElement Invert()
{
return new F2mFieldElement(this.m, this.ks, this.x.ModInverse(m, ks));
@@ -819,14 +834,7 @@ namespace Org.BouncyCastle.Math.EC
public override ECFieldElement Sqrt()
{
- LongArray x1 = this.x;
- if (x1.IsOne() || x1.IsZero())
- {
- return this;
- }
-
- LongArray x2 = x1.ModSquareN(m - 1, m, ks);
- return new F2mFieldElement(m, ks, x2);
+ return (x.IsZero() || x.IsOne()) ? this : SquarePow(m - 1);
}
/**
|
