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-rw-r--r--libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/ec/ECNewRandomnessTransform.java90
1 files changed, 0 insertions, 90 deletions
diff --git a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/ec/ECNewRandomnessTransform.java b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/ec/ECNewRandomnessTransform.java
deleted file mode 100644
index 9b70fc467..000000000
--- a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/ec/ECNewRandomnessTransform.java
+++ /dev/null
@@ -1,90 +0,0 @@
-package org.spongycastle.crypto.ec;
-
-import java.math.BigInteger;
-import java.security.SecureRandom;
-
-import org.spongycastle.crypto.CipherParameters;
-import org.spongycastle.crypto.params.ECPublicKeyParameters;
-import org.spongycastle.crypto.params.ParametersWithRandom;
-import org.spongycastle.math.ec.ECPoint;
-
-/**
- * this transforms the original randomness used for an ElGamal encryption.
- */
-public class ECNewRandomnessTransform
- implements ECPairFactorTransform
-{
- private ECPublicKeyParameters key;
- private SecureRandom random;
-
- private BigInteger lastK;
-
- /**
- * initialise the underlying EC ElGamal engine.
- *
- * @param param the necessary EC key parameters.
- */
- public void init(
- CipherParameters param)
- {
- if (param instanceof ParametersWithRandom)
- {
- ParametersWithRandom p = (ParametersWithRandom)param;
-
- if (!(p.getParameters() instanceof ECPublicKeyParameters))
- {
- throw new IllegalArgumentException("ECPublicKeyParameters are required for new randomness transform.");
- }
-
- this.key = (ECPublicKeyParameters)p.getParameters();
- this.random = p.getRandom();
- }
- else
- {
- if (!(param instanceof ECPublicKeyParameters))
- {
- throw new IllegalArgumentException("ECPublicKeyParameters are required for new randomness transform.");
- }
-
- this.key = (ECPublicKeyParameters)param;
- this.random = new SecureRandom();
- }
- }
-
- /**
- * Transform an existing cipher test 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.
- *
- * @param cipherText the EC point to process.
- * @return returns a new ECPair representing the result of the process.
- */
- public ECPair transform(ECPair cipherText)
- {
- if (key == null)
- {
- 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());
-
- lastK = k;
-
- return new ECPair(cipherText.getX().add(gamma).normalize(), phi.normalize());
- }
-
- /**
- * Return the last random value generated for a transform
- *
- * @return a BigInteger representing the last random value.
- */
- public BigInteger getTransformValue()
- {
- return lastK;
- }
-}