Package org.bouncycastle.crypto.commitments

Class HashCommitter

java.lang.Object
org.bouncycastle.crypto.commitments.HashCommitter
All Implemented Interfaces:
Committer
public class HashCommitter extends Object implements Committer
A basic hash-committer as described in "Making Mix Nets Robust for Electronic Voting by Randomized Partial Checking", by Jakobsson, Juels, and Rivest (11th Usenix Security Symposium, 2002).

Use this class if you can enforce fixed length for messages. If you need something more general, use the GeneralHashCommitter.

  • Constructor Details

    • HashCommitter

      public HashCommitter(ExtendedDigest digest, SecureRandom random)
      Base Constructor. The maximum message length that can be committed to is half the length of the internal block size for the digest (ExtendedDigest.getBlockLength()).
      Parameters:
      digest - digest to use for creating commitments.
      random - source of randomness for generating secrets.

  • Method Details

    • commit

      public Commitment commit(byte[] message)
      Generate a commitment for the passed in message.
      Specified by:
      commit in interface Committer
      Parameters:
      message - the message to be committed to,
      Returns:
      a Commitment

    • isRevealed

      public boolean isRevealed(Commitment commitment, byte[] message)
      Return true if the passed in commitment represents a commitment to the passed in message.
      Specified by:
      isRevealed in interface Committer
      Parameters:
      commitment - a commitment previously generated.
      message - the message that was expected to have been committed to.
      Returns:
      true if commitment matches message, false otherwise.