1 files changed, 30 insertions, 0 deletions
diff --git a/crypto/src/math/ec/multiplier/NafL2RMultiplier.cs b/crypto/src/math/ec/multiplier/NafL2RMultiplier.cs
new file mode 100644
index 000000000..ac80cf905
--- /dev/null
+++ b/crypto/src/math/ec/multiplier/NafL2RMultiplier.cs
@@ -0,0 +1,30 @@
+namespace Org.BouncyCastle.Math.EC.Multiplier
+{
+    /**
+     * Class implementing the NAF (Non-Adjacent Form) multiplication algorithm (left-to-right).
+     */
+    public class NafL2RMultiplier
+        : AbstractECMultiplier
+    {
+        protected override ECPoint MultiplyPositive(ECPoint p, BigInteger k)
+        {
+            int[] naf = WNafUtilities.GenerateCompactNaf(k);
+
+            ECPoint addP = p.Normalize(), subP = addP.Negate();
+
+            ECPoint R = p.Curve.Infinity;
+
+            int i = naf.Length;
+            while (--i >= 0)
+            {
+                int ni = naf[i];
+                int digit = ni >> 16, zeroes = ni & 0xFFFF;
+
+                R = R.TwicePlus(digit < 0 ? subP : addP);
+                R = R.TimesPow2(zeroes);
+            }
+
+            return R;
+        }
+    }
+}