cryptix.provider.cipher

Class LOKI91

public final class LOKI91 extends Cipher implements SymmetricCipher

LOKI is a proposed Australian alternative cipher to DES. It was first designed by L. Brown, J. Pieprzyk and J. Seberry in 1990 and later re- designed (and renamed LOKI91), with improved resistance to differential cryptanalysis, by L. Brown, M. Kwan, J. Pieprzyk and J. Seberry.

LOKI91 is a 64-bit symmetric block cipher with a 64-bit user key. See LOKI91KeyGenerator for information about weak keys.

This current version is based on special C-code obtained, under license, from The School of Computer Science, UC, UNSW. The speed gain is achieved by pre-computing the 4,096 values of the substitutions (S-Box) used by the algorithm as well as the permutations for all possible 256 input values for each of the four 8-bit blocks.

References:

  1. Bruce Schneier, Applied Cryptography, 2nd edition, John Wiley & Sons 1996, 314-316.

  2. Personal correspondance with Dr. Lawrence Brown.

Copyright © 1997 Systemics Ltd on behalf of the Cryptix Development Team.
All rights reserved.

$Revision: 1.3 $

Since: Cryptix 2.2.2

Author: Raif S. Naffah

Constructor Summary
LOKI91()
Constructs a LOKI91 cipher object, in the UNINITIALIZED state.
Method Summary
Objectclone()
Always throws a CloneNotSupportedException (cloning of ciphers is not supported for security reasons).
protected intengineBlockSize()
SPI: Returns the length of an input block, in bytes.
protected voidengineInitDecrypt(Key key)
SPI: Initializes this cipher for decryption, using the specified key.
protected voidengineInitEncrypt(Key key)
SPI: Initializes this cipher for encryption, using the specified key.
protected intengineUpdate(byte[] in, int inOffset, int inLen, byte[] out, int outOffset)
SPI: This is the main engine method for updating data.
protected voidfinalize()
Cleans up resources used by this instance, if necessary.
static LinkStatusgetLinkStatus()
Gets an object representing the native linking status of this class.

Constructor Detail

LOKI91

public LOKI91()
Constructs a LOKI91 cipher object, in the UNINITIALIZED state. This calls the Cipher constructor with implBuffering false, implPadding false and the provider set to "Cryptix".

Method Detail

clone

public final Object clone()
Always throws a CloneNotSupportedException (cloning of ciphers is not supported for security reasons).

engineBlockSize

protected int engineBlockSize()
SPI: Returns the length of an input block, in bytes.

Returns: the length in bytes of an input block for this cipher.

engineInitDecrypt

protected void engineInitDecrypt(Key key)
SPI: Initializes this cipher for decryption, using the specified key.

Parameters: key the key to use for decryption.

Throws: KeyException if the key is invalid.

engineInitEncrypt

protected void engineInitEncrypt(Key key)
SPI: Initializes this cipher for encryption, using the specified key.

Parameters: key the key to use for encryption.

Throws: KeyException if the key is invalid.

engineUpdate

protected int engineUpdate(byte[] in, int inOffset, int inLen, byte[] out, int outOffset)
SPI: This is the main engine method for updating data.

in and out may be the same array, and the input and output regions may overlap.

Parameters: in the input data. inOffset the offset into in specifying where the data starts. inLen the length of the subarray. out the output array. outOffset the offset indicating where to start writing into the out array.

Returns: the number of bytes written.

Throws: CryptixException if the native library is being used, and it reports an error.

finalize

protected final void finalize()
Cleans up resources used by this instance, if necessary.

getLinkStatus

public static LinkStatus getLinkStatus()
Gets an object representing the native linking status of this class.