cryptix.provider.cipher
Class SPEED

java.lang.Object
  |
  +--xjava.security.IJCE_Traceable
        |
        +--xjava.security.Cipher
              |
              +--cryptix.provider.cipher.SPEED

All Implemented Interfaces:

Parameterized, SymmetricCipher

public final class SPEED

extends Cipher

implements SymmetricCipher

SPEED is a block cipher with variable key size, data block size and number of rounds (in the style of RC5).

These parameters are set as follows:

• The key size is taken from the encoded form of the key passed to initEncrypt or initDecrypt. It can be any even number of bytes from 6 to 32 (6, 8, 10, ... 32).

• The length of the data block defaults to the value of the parameter "Alg.blockSize.SPEED", or 8 bytes (c.f. IDEA and DES) if that parameter is not found. It can be set by calling setBlockSize(), and can be 8, 16, or 32 bytes.

• The number of rounds defaults to the value of the parameter "Alg.rounds.SPEED", or 64 (which gives 'adequate' security according to the paper below) if that parameter is not found. It can be set by calling setRounds(), and can be any number from 32 upwards, divisible by 4 (32, 36, ...).

These are recommended settings for 'adequate' security:

    +--------------------------------------------------+
    |   block size   |   key length   |     rounds     |
    |==================================================|
    |       8        |      >= 8      |     >= 64      |
    |--------------------------------------------------|
    |      16        |      >= 8      |     >= 48      |
    |--------------------------------------------------|
    |      32        |      >= 8      |     >= 48      |
    +--------------------------------------------------+
 

SPEED was designed by Yuliang Zheng, and is in the public domain.

References:

1. Y. Zheng "The SPEED Cipher," Proceedings of Financial Cryptography 97, Springer-Verlag (forthcoming). FC97 held at Anguilla, BWI, 24-28 February 1997.

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

$Revision: 1.6 $

Since:

Cryptix 2.2.2

Author:

Systemics Ltd, David Hopwood

Field Summary

Fields inherited from class xjava.security.Cipher

DECRYPT, ENCRYPT, UNINITIALIZED

Constructor Summary

SPEED()
Constructs a SPEED cipher object, in the UNINITIALIZED state.

Method Summary

protected void	blockDecrypt(byte[] in, int in_offset, byte[] out, int out_offset) Decrypts a block.
protected void	blockEncrypt(byte[] in, int in_offset, byte[] out, int out_offset) Encrypts a block.
java.lang.Object	clone() Always throws a CloneNotSupportedException (cloning of ciphers is not supported for security reasons).
(package private) void	dump()
protected int	engineBlockSize() SPI: Return the data block length of this cipher.
protected java.lang.Object	engineGetParameter(java.lang.String param) SPI: Gets the value of the specified algorithm parameter.
void	engineInitDecrypt(java.security.Key key) SPI: Initializes this cipher for decryption, using the specified key.
void	engineInitEncrypt(java.security.Key key) SPI: Initializes this cipher for encryption, using the specified key.
protected void	engineSetParameter(java.lang.String param, java.lang.Object value) SPI: Sets the specified algorithm parameter to the specified value.
protected int	engineUpdate(byte[] in, int inOffset, int inLen, byte[] out, int outOffset) SPI: This is the main engine method for updating data.
protected void	finalize() Cleans up resources used by this instance, if necessary.
static LinkStatus	getLinkStatus() Gets an object representing the native linking status of this class.
int	getRounds() Returns the currently set number of rounds for this instance.
static void	main(java.lang.String[] argv) Entry point for self_test.
static void	self_test(java.io.PrintWriter out, java.lang.String[] argv) Runs algorithm through test data, including certification data provided in paper.
void	setBlockSize(int blocksize) Sets the block size in bytes for this cipher.
void	setRounds(int rounds) Sets the number of rounds for this cipher.

Methods inherited from class xjava.security.Cipher

blockSize, crypt, crypt, crypt, doFinal, doFinal, doFinal, doFinal, engineCiphertextBlockSize, engineCrypt, engineInBufferSize, engineOutBufferSize, enginePlaintextBlockSize, engineSetPaddingScheme, getAlgorithm, getAlgorithms, getAlgorithms, getCiphertextBlockSize, getInputBlockSize, getInstance, getInstance, getInstance, getMode, getOutputBlockSize, getPadding, getPaddingScheme, getParameter, getPlaintextBlockSize, getProvider, getState, inBufferSize, inBufferSizeFinal, initDecrypt, initEncrypt, isPaddingBlockCipher, outBufferSize, outBufferSizeFinal, setParameter, toString, update, update, update, update

Methods inherited from class java.lang.Object

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

Constructor Detail

SPEED

public SPEED()

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

Method Detail

getLinkStatus

public static LinkStatus getLinkStatus()

Gets an object representing the native linking status of this class.

finalize

protected final void finalize()

Cleans up resources used by this instance, if necessary.

Overrides:

finalize in class java.lang.Object

clone

public final java.lang.Object clone()
                             throws java.lang.CloneNotSupportedException

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

Overrides:

clone in class Cipher

Throws:

java.lang.CloneNotSupportedException - if the cipher is not cloneable.

engineBlockSize

protected int engineBlockSize()

SPI: Return the data block length of this cipher. Default (8 bytes) is returned before instantiation, actual length used by object returned after instantiation.

Overrides:

engineBlockSize in class Cipher

Returns:

the block length in bytes.

engineInitEncrypt

public void engineInitEncrypt(java.security.Key key)
                       throws java.security.InvalidKeyException

SPI: Initializes this cipher for encryption, using the specified key.

Specified by:

engineInitEncrypt in class Cipher

Parameters:

key - the key to use for encryption.

Throws:

java.security.InvalidKeyException - if one of the following occurs:

• key.getEncoded() == null;
• The length of the user key array is not ...

engineInitDecrypt

public void engineInitDecrypt(java.security.Key key)
                       throws java.security.InvalidKeyException,
                              CryptixException

SPI: Initializes this cipher for decryption, using the specified key.

Specified by:

engineInitDecrypt in class Cipher

Parameters:

key - the key to use for decryption.

Throws:

java.security.InvalidKeyException - if one of the following occurs:

• key.getEncoded() == null;
• The length of the user key array is not ...

CryptixException

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.

Specified by:

engineUpdate in class Cipher

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.

engineSetParameter

protected void engineSetParameter(java.lang.String param,
                                  java.lang.Object value)
                           throws NoSuchParameterException,
                                  java.security.InvalidParameterException,
                                  InvalidParameterTypeException

SPI: Sets the specified algorithm parameter to the specified value.

SPEED has two parameters:

• "rounds", which specifies the number of rounds for this instance as a decimal String.
• "blockSize", which specifies the block size for this instance, also as a decimal String.

Overrides:

engineSetParameter in class Cipher

Parameters:

param - the string name of the parameter.

value - the parameter value.

Throws:

java.security.InvalidParameterException - if param is an invalid parameter for this cipher implementation, the parameter is already set and cannot be set again, a security exception occurs, and so on.

InvalidParameterTypeException - if value is of the wrong type.

NoSuchParameterException - if there is no parameter with name param for this cipher implementation.

engineGetParameter

protected java.lang.Object engineGetParameter(java.lang.String param)
                                       throws NoSuchParameterException,
                                              java.security.InvalidParameterException

SPI: Gets the value of the specified algorithm parameter.

SPEED has two parameters:

• "rounds", which specifies the number of rounds for this instance as a decimal String.
• "blockSize", which specifies the block size for this instance, also as a decimal String.

Overrides:

engineGetParameter in class Cipher

Parameters:

param - the string name of the parameter.

Returns:

the object that represents the parameter value, or null if there is none.

Throws:

java.security.InvalidParameterException - if the parameter exists but cannot be read.

NoSuchParameterException - if there is no parameter with name param for this cipher implementation.

setRounds

public void setRounds(int rounds)

Sets the number of rounds for this cipher. Allowed only when this cipher is in the UNINITIALIZED state; otherwise an exception is thrown.

If the specified number is invalid, an IllegalArgumentException is thrown.

Parameters:

rounds - the desired number of rounds: >= 32, multiple of 4

Throws:

java.lang.IllegalStateException - if this cipher is not uninitialised.

java.security.InvalidParameterException - if the given number of rounds is not supported.

getRounds

public int getRounds()

Returns the currently set number of rounds for this instance.

Returns:

the number of rounds.

setBlockSize

public void setBlockSize(int blocksize)

Sets the block size in bytes for this cipher. Allowed only when this cipher is in the UNINITIALIZED state; otherwise an exception is thrown.

If the specified number is invalid, an IllegalArgumentException is thrown.

Parameters:

blocksize - the desired block size in bytes: 8, 16 or 32

Throws:

java.lang.IllegalStateException - if this cipher is not uninitialised.

java.lang.IllegalArgumentException - if the given number of rounds is not supported.

dump

void dump()

blockEncrypt

protected void blockEncrypt(byte[] in,
                            int in_offset,
                            byte[] out,
                            int out_offset)

Encrypts a block. The in and out buffers can be the same.

Parameters:

in - The data to be encrypted.

in_offset - The start of data within the in buffer.

out - The encrypted data.

out_offset - The start of data within the out buffer.

blockDecrypt

protected void blockDecrypt(byte[] in,
                            int in_offset,
                            byte[] out,
                            int out_offset)

Decrypts a block. The in and out buffers can be the same.

Parameters:

in - The data to be decrypted.

in_offset - The start of data within the in buffer.

out - The decrypted data.

out_offset - The start of data within the out buffer.

main

public static final void main(java.lang.String[] argv)

Entry point for self_test.

self_test

public static void self_test(java.io.PrintWriter out,
                             java.lang.String[] argv)
                      throws java.lang.Exception

Runs algorithm through test data, including certification data provided in paper.

java.lang.Exception