cryptix.provider.cipher

Class SPEED

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:

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

Constructor Summary
SPEED()
Constructs a SPEED cipher object, in the UNINITIALIZED state.
Method Summary
protected voidblockDecrypt(byte[] in, int in_offset, byte[] out, int out_offset)
Decrypts a block.
protected voidblockEncrypt(byte[] in, int in_offset, byte[] out, int out_offset)
Encrypts a block.
Objectclone()
Always throws a CloneNotSupportedException (cloning of ciphers is not supported for security reasons).
voiddump()
protected intengineBlockSize()
SPI: Return the data block length of this cipher.
protected ObjectengineGetParameter(String param)
SPI: Gets the value of the specified algorithm parameter.
voidengineInitDecrypt(Key key)
SPI: Initializes this cipher for decryption, using the specified key.
voidengineInitEncrypt(Key key)
SPI: Initializes this cipher for encryption, using the specified key.
protected voidengineSetParameter(String param, Object value)
SPI: Sets the specified algorithm parameter to the specified value.
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.
intgetRounds()
Returns the currently set number of rounds for this instance.
static voidmain(String[] argv)
Entry point for self_test.
static voidself_test(PrintWriter out, String[] argv)
Runs algorithm through test data, including certification data provided in paper.
voidsetBlockSize(int blocksize)
Sets the block size in bytes for this cipher.
voidsetRounds(int rounds)
Sets the number of rounds for this cipher.

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

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.

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.

clone

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

dump

void dump()

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.

Returns: the block length in bytes.

engineGetParameter

protected Object engineGetParameter(String param)
SPI: Gets the value of the specified algorithm parameter.

SPEED has two parameters:

Parameters: param the string name of the parameter.

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

engineInitDecrypt

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

Parameters: key the key to use for decryption.

Throws: InvalidKeyException if one of the following occurs:

engineInitEncrypt

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

Parameters: key the key to use for encryption.

Throws: InvalidKeyException if one of the following occurs:

engineSetParameter

protected void engineSetParameter(String param, Object value)
SPI: Sets the specified algorithm parameter to the specified value.

SPEED has two parameters:

Parameters: param the string name of the parameter. value the parameter value.

Throws: 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.

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.

getRounds

public int getRounds()
Returns the currently set number of rounds for this instance.

Returns: the number of rounds.

main

public static final void main(String[] argv)
Entry point for self_test.

self_test

public static void self_test(PrintWriter out, String[] argv)
Runs algorithm through test data, including certification data provided in paper.

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: IllegalStateException if this cipher is not uninitialised. IllegalArgumentException if the given number of rounds is not supported.

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: IllegalStateException if this cipher is not uninitialised. InvalidParameterException if the given number of rounds is not supported.