Use FixedPointCombMultiplier for most base-point multiplications

4 files changed, 45 insertions, 16 deletions

diff --git a/core/src/main/java/org/bouncycastle/crypto/ec/ECElGamalEncryptor.java b/core/src/main/java/org/bouncycastle/crypto/ec/ECElGamalEncryptor.java
index 0e893ea1..a5296830 100644
--- a/core/src/main/java/org/bouncycastle/crypto/ec/ECElGamalEncryptor.java
+++ b/core/src/main/java/org/bouncycastle/crypto/ec/ECElGamalEncryptor.java
@@ -7,7 +7,9 @@ import org.bouncycastle.crypto.CipherParameters;
 import org.bouncycastle.crypto.params.ECDomainParameters;
 import org.bouncycastle.crypto.params.ECPublicKeyParameters;
 import org.bouncycastle.crypto.params.ParametersWithRandom;
+import org.bouncycastle.math.ec.ECMultiplier;
 import org.bouncycastle.math.ec.ECPoint;
+import org.bouncycastle.math.ec.FixedPointCombMultiplier;
 
 /**
  * this does your basic ElGamal encryption algorithm using EC
@@ -65,8 +67,10 @@ public class ECElGamalEncryptor
         ECDomainParameters ec = key.getParameters();
         BigInteger k = ECUtil.generateK(ec.getN(), random);
 
+        ECMultiplier basePointMultiplier = new FixedPointCombMultiplier();
+
         ECPoint[] gamma_phi = new ECPoint[]{
-            ec.getG().multiply(k),
+            basePointMultiplier.multiply(ec.getG(), k),
             key.getQ().multiply(k).add(point)
         };
 
diff --git a/core/src/main/java/org/bouncycastle/crypto/ec/ECFixedTransform.java b/core/src/main/java/org/bouncycastle/crypto/ec/ECFixedTransform.java
index c382059d..02f5ca37 100644
--- a/core/src/main/java/org/bouncycastle/crypto/ec/ECFixedTransform.java
+++ b/core/src/main/java/org/bouncycastle/crypto/ec/ECFixedTransform.java
@@ -5,7 +5,9 @@ import java.math.BigInteger;
 import org.bouncycastle.crypto.CipherParameters;
 import org.bouncycastle.crypto.params.ECDomainParameters;
 import org.bouncycastle.crypto.params.ECPublicKeyParameters;
+import org.bouncycastle.math.ec.ECMultiplier;
 import org.bouncycastle.math.ec.ECPoint;
+import org.bouncycastle.math.ec.FixedPointCombMultiplier;
 
 /**
  * this transforms the original randomness used for an ElGamal encryption by a fixed value.
@@ -39,7 +41,7 @@ public class ECFixedTransform
     }
 
     /**
-     * Transform an existing cipher test pair using the ElGamal algorithm. Note: it is assumed this
+     * Transform an existing cipher text pair using the ElGamal algorithm. Note: it is assumed this
      * transform has been initialised with the same public key that was used to create the original
      * cipher text.
      *
@@ -54,9 +56,13 @@ public class ECFixedTransform
         }
 
         ECDomainParameters ec = key.getParameters();
+        BigInteger n = ec.getN();
+
+        ECMultiplier basePointMultiplier = new FixedPointCombMultiplier();
+        BigInteger k = this.k.mod(n);
 
         ECPoint[] gamma_phi = new ECPoint[]{
-            ec.getG().multiply(k).add(cipherText.getX()),
+            basePointMultiplier.multiply(ec.getG(), k).add(cipherText.getX()),
             key.getQ().multiply(k).add(cipherText.getY())
         };
 
diff --git a/core/src/main/java/org/bouncycastle/crypto/ec/ECNewPublicKeyTransform.java b/core/src/main/java/org/bouncycastle/crypto/ec/ECNewPublicKeyTransform.java
index 74016c18..9f7a0bf1 100644
--- a/core/src/main/java/org/bouncycastle/crypto/ec/ECNewPublicKeyTransform.java
+++ b/core/src/main/java/org/bouncycastle/crypto/ec/ECNewPublicKeyTransform.java
@@ -4,9 +4,12 @@ import java.math.BigInteger;
 import java.security.SecureRandom;
 
 import org.bouncycastle.crypto.CipherParameters;
+import org.bouncycastle.crypto.params.ECDomainParameters;
 import org.bouncycastle.crypto.params.ECPublicKeyParameters;
 import org.bouncycastle.crypto.params.ParametersWithRandom;
+import org.bouncycastle.math.ec.ECMultiplier;
 import org.bouncycastle.math.ec.ECPoint;
+import org.bouncycastle.math.ec.FixedPointCombMultiplier;
 
 /**
  * this does your basic Elgamal encryption algorithm using EC
@@ -49,7 +52,7 @@ public class ECNewPublicKeyTransform
     }
 
     /**
-     * Transform an existing cipher test pair using the ElGamal algorithm. Note: the input cipherText will
+     * Transform an existing cipher text pair using the ElGamal algorithm. Note: the input cipherText will
      * need to be preserved in order to complete the transformation to the new public key.
      *
      * @param cipherText the EC point to process.
@@ -62,13 +65,19 @@ public class ECNewPublicKeyTransform
             throw new IllegalStateException("ECNewPublicKeyTransform not initialised");
         }
 
-        BigInteger             n = key.getParameters().getN();
-        BigInteger             k = ECUtil.generateK(n, random);
+        ECDomainParameters ec = key.getParameters();
+        BigInteger n = ec.getN();
 
-        ECPoint  g = key.getParameters().getG();
-        ECPoint  gamma = g.multiply(k);
-        ECPoint  phi = key.getQ().multiply(k).add(cipherText.getY());
+        ECMultiplier basePointMultiplier = new FixedPointCombMultiplier();
+        BigInteger k = ECUtil.generateK(n, random);
 
-        return new ECPair(gamma.normalize(), phi.normalize());
+        ECPoint[] gamma_phi = new ECPoint[]{
+            basePointMultiplier.multiply(ec.getG(), k),
+            key.getQ().multiply(k).add(cipherText.getY())
+        };
+
+        ec.getCurve().normalizeAll(gamma_phi);
+
+        return new ECPair(gamma_phi[0], gamma_phi[1]);
     }
 }
diff --git a/core/src/main/java/org/bouncycastle/crypto/ec/ECNewRandomnessTransform.java b/core/src/main/java/org/bouncycastle/crypto/ec/ECNewRandomnessTransform.java
index b293759a..c146a0fb 100644
--- a/core/src/main/java/org/bouncycastle/crypto/ec/ECNewRandomnessTransform.java
+++ b/core/src/main/java/org/bouncycastle/crypto/ec/ECNewRandomnessTransform.java
@@ -4,9 +4,12 @@ import java.math.BigInteger;
 import java.security.SecureRandom;
 
 import org.bouncycastle.crypto.CipherParameters;
+import org.bouncycastle.crypto.params.ECDomainParameters;
 import org.bouncycastle.crypto.params.ECPublicKeyParameters;
 import org.bouncycastle.crypto.params.ParametersWithRandom;
+import org.bouncycastle.math.ec.ECMultiplier;
 import org.bouncycastle.math.ec.ECPoint;
+import org.bouncycastle.math.ec.FixedPointCombMultiplier;
 
 /**
  * this transforms the original randomness used for an ElGamal encryption.
@@ -66,16 +69,23 @@ public class ECNewRandomnessTransform
             throw new IllegalStateException("ECNewRandomnessTransform not initialised");
         }
 
-        BigInteger             n = key.getParameters().getN();
-        BigInteger             k = ECUtil.generateK(n, random);
 
-        ECPoint  g = key.getParameters().getG();
-        ECPoint  gamma = g.multiply(k);
-        ECPoint  phi = key.getQ().multiply(k).add(cipherText.getY());
+        ECDomainParameters ec = key.getParameters();
+        BigInteger n = ec.getN();
+
+        ECMultiplier basePointMultiplier = new FixedPointCombMultiplier();
+        BigInteger k = ECUtil.generateK(n, random);
+
+        ECPoint[] gamma_phi = new ECPoint[]{
+            basePointMultiplier.multiply(ec.getG(), k).add(cipherText.getX()),
+            key.getQ().multiply(k).add(cipherText.getY())
+        };
+
+        ec.getCurve().normalizeAll(gamma_phi);
 
         lastK = k;
 
-        return new ECPair(cipherText.getX().add(gamma).normalize(), phi.normalize());
+        return new ECPair(gamma_phi[0], gamma_phi[1]);
     }
 
     /**