gnu.crypto.cipher

Class Khazad

Implemented Interfaces:
Cloneable, IBlockCipher, IBlockCipherSpi

public final class Khazad
extends BaseCipher

Khazad is a 64-bit (legacy-level) block cipher that accepts a 128-bit key. The cipher is a uniform substitution-permutation network whose inverse only differs from the forward operation in the key schedule. The overall cipher design follows the Wide Trail strategy, favours component reuse, and permits a wide variety of implementation trade-offs.

References:

  1. The Khazad Block Cipher.
    Paulo S.L.M. Barreto and Vincent Rijmen.

Version:
$Revision: 1.9 $

Field Summary

Fields inherited from class gnu.crypto.cipher.BaseCipher

currentBlockSize, currentKey, defaultBlockSize, defaultKeySize, lock, name

Fields inherited from interface gnu.crypto.cipher.IBlockCipher

CIPHER_BLOCK_SIZE, KEY_MATERIAL

Constructor Summary

Khazad()
Trivial 0-arguments constructor.

Method Summary

Iterator
blockSizes()
Returns an java.util.Iterator over the supported block sizes.
Object
clone()
void
decrypt(byte[] in, int i, byte[] out, int j, Object k, int bs)
Decrypts exactly one block of ciphertext.
void
encrypt(byte[] in, int i, byte[] out, int j, Object k, int bs)
Encrypts exactly one block of plaintext.
Iterator
keySizes()
Returns an java.util.Iterator over the supported key sizes.
Object
makeKey(byte[] uk, int bs)
Expands a user-supplied key material into a session key for a designated block size.
boolean
selfTest()
A correctness test that consists of basic symmetric encryption / decryption test(s) for all supported block and key sizes, as well as one (1) variable key Known Answer Test (KAT).

Methods inherited from class gnu.crypto.cipher.BaseCipher

clone, currentBlockSize, decryptBlock, defaultBlockSize, defaultKeySize, encryptBlock, init, name, reset, selfTest, testKat, testKat

Constructor Details

Khazad

public Khazad()
Trivial 0-arguments constructor.

Method Details

blockSizes

public Iterator blockSizes()
Returns an java.util.Iterator over the supported block sizes. Each element returned by this object is a java.lang.Integer.
Specified by:
blockSizes in interface IBlockCipher
blockSizes in interface IBlockCipherSpi

Returns:
an Iterator over the supported block sizes.


clone

public Object clone()
Specified by:
clone in interface IBlockCipher
Overrides:
clone in interface BaseCipher


decrypt

public void decrypt(byte[] in,
                    int i,
                    byte[] out,
                    int j,
                    Object k,
                    int bs)
Decrypts exactly one block of ciphertext.
Specified by:
decrypt in interface IBlockCipherSpi

Parameters:
in - the ciphertext.
out - the plaintext.
k - the session key to use.
bs - the block size to use.


encrypt

public void encrypt(byte[] in,
                    int i,
                    byte[] out,
                    int j,
                    Object k,
                    int bs)
Encrypts exactly one block of plaintext.
Specified by:
encrypt in interface IBlockCipherSpi

Parameters:
in - the plaintext.
out - the ciphertext.
k - the session key to use.
bs - the block size to use.


keySizes

public Iterator keySizes()
Returns an java.util.Iterator over the supported key sizes. Each element returned by this object is a java.lang.Integer.
Specified by:
keySizes in interface IBlockCipher
keySizes in interface IBlockCipherSpi

Returns:
an Iterator over the supported key sizes.


makeKey

public Object makeKey(byte[] uk,
                      int bs)
            throws InvalidKeyException
Expands a user-supplied key material into a session key for a designated block size.
Specified by:
makeKey in interface IBlockCipherSpi

Parameters:
uk - the 128-bit user-supplied key material.
bs - the desired block size in bytes.

Returns:
an Object encapsulating the session key.


selfTest

public boolean selfTest()
A correctness test that consists of basic symmetric encryption / decryption test(s) for all supported block and key sizes, as well as one (1) variable key Known Answer Test (KAT).
Specified by:
selfTest in interface IBlockCipher
selfTest in interface IBlockCipherSpi
Overrides:
selfTest in interface BaseCipher

Returns:
true if the implementation passes simple correctness tests. Returns false otherwise.


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