Package org.bouncycastle.crypto.ec

Class ECFixedTransform

java.lang.Object
org.bouncycastle.crypto.ec.ECFixedTransform
All Implemented Interfaces:
ECPairFactorTransform, ECPairTransform
public class ECFixedTransform extends Object implements ECPairFactorTransform
this transforms the original randomness used for an ElGamal encryption by a fixed value.

  • Constructor Details

    • ECFixedTransform

      public ECFixedTransform(BigInteger k)

  • Method Details

    • init

      public void init(CipherParameters param)
      initialise the underlying EC ElGamal engine.
      Specified by:
      init in interface ECPairTransform
      Parameters:
      param - the necessary EC key parameters.

    • transform

      public ECPair transform(ECPair cipherText)
      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.
      Specified by:
      transform in interface ECPairTransform
      Parameters:
      cipherText - the EC point to process.
      Returns:
      returns a new ECPair representing the result of the process.

    • getTransformValue

      public BigInteger getTransformValue()
      Return the last transform value used by the transform
      Specified by:
      getTransformValue in interface ECPairFactorTransform
      Returns:
      a BigInteger representing k value.

    • createBasePointMultiplier

      protected ECMultiplier createBasePointMultiplier()