iaik.security.md

Class BLAKE224

java.lang.Object

java.security.MessageDigestSpi

java.security.MessageDigest

iaik.security.md.AbstractMessageDigest

iaik.security.md.BLAKE224

All Implemented Interfaces:

java.lang.Cloneable

public final class BLAKE224
extends AbstractMessageDigest

This class implements the BLAKE message digest algorithm.

A message digest algorithm represents the functionality of an one-way hash function for computing a fixed sized data value (message digest, hash) from input data of arbitrary size. The length of the resulting hash value usually is shorter than the length of the input data. Using a one-way hash function will make it easy to compute the hash from the given data, but hard to go the reverse way for calculating the input data when only the hash is known. Furthermore, a proper hash function should avoid any collision, meaning that it has to be hard to find two different messages producing the same hash value.

The BLAKE-224 message digest algorithm produces a 224-bit hash-value of the given input data.

This class extends the java.security.MessageDigest class and applications should use one of the getInstance methods presented there to create a MessageDigest-BLAKE object. Generally, an application wishing to compute the message digest of some data has to perform three steps:

• First an instance of the desired message digest algorithm has to be created using a proper getInstance method, e.g.:

   MessageDigest BLAKE = MessageDigest.getInstance("BLAKE224");
   

• Second, the data to be hashed is supplied to the MessageDigest object just created by one or more calls to one of the update methods, e.g:
  

       BLAKE.update(m1);
       BLAKE.update(m2);
       ...
   

• Finally, the hash value can be computed using one of the digest methods:
  

   byte[] hash_value = BLAKE.digest();
   

There are several ways for combining update and digest methods for computing a message digest. Since this class implements the Cloneable interface, BLAKE MessageDigest objects may be used for compute intermediate hashes through cloning (see http ://java.sun.com/products/JDK/1.2/docs/guide/security/CryptoSpec.html).

When the hash value successfully has been computed, the BLAKE MessageDigest object automatically resets for being able to be supplied with new data to be hashed..

See Also:

MessageDigest

Constructor Summary

Constructors

Constructor and Description
BLAKE224() Default constructor.

Method Summary

Methods

Modifier and Type	Method and Description
java.lang.Object	clone() Return a clone of this message digest that can be used independently of this instance.
protected void	engineReset() SPI: Resets this message digest for further use.

Methods inherited from class iaik.security.md.AbstractMessageDigest

engineDigest, engineDigest, engineGetDigestLength, engineUpdate, engineUpdate

Methods inherited from class java.security.MessageDigest

digest, digest, digest, getAlgorithm, getDigestLength, getInstance, getInstance, getInstance, getProvider, isEqual, reset, toString, update, update, update, update

Methods inherited from class java.security.MessageDigestSpi

engineUpdate

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

BLAKE224

public BLAKE224()

Default constructor.

Method Detail

engineReset

protected void engineReset()

Description copied from class: AbstractMessageDigest

SPI: Resets this message digest for further use.

clone

public java.lang.Object clone()

Description copied from class: AbstractMessageDigest

Return a clone of this message digest that can be used independently of this instance.

Overrides:

clone in class AbstractMessageDigest

Returns:

A clone of this message digest.