gnu.crypto.prng

Class ICMGenerator

public class ICMGenerator extends BasePRNG implements Cloneable

Counter Mode is a way to define a pseudorandom keystream generator using a block cipher. The keystream can be used for additive encryption, key derivation, or any other application requiring pseudorandom data.

In ICM, the keystream is logically broken into segments. Each segment is identified with a segment index, and the segments have equal lengths. This segmentation makes ICM especially appropriate for securing packet-based protocols.

This implementation adheres to the definition of the ICM keystream generation function that allows for any symetric key block cipher algorithm (initialisation parameter gnu.crypto.prng.icm.cipher.name taken to be an instance of java.lang.String) to be used. If such a parameter is not defined/included in the initialisation Map, then the "Rijndael" algorithm is used. Furthermore, if the initialisation parameter gnu.crypto.cipher.block.size (taken to be a instance of java.lang.Integer) is missing or undefined in the initialisation Map, then the cipher's default block size is used.

The practical limits and constraints of such generator are:

NOTE: Rijndael is used as the default symmetric key block cipher algorithm because, with its default block and key sizes, it is the AES. Yet being Rijndael, the algorithm offers more versatile block and key sizes which may prove to be useful for generating longer key streams.

References:

  1. Integer Counter Mode, David A. McGrew.

Version: $Revision: 1.13 $

Field Summary
static StringBLOCK_INDEX_LENGTH
Property name of ICM's block index length.
static StringCIPHER
Property name of underlying block cipher for this ICM generator.
static StringOFFSET
Property name of ICM's offset.
static StringSEGMENT_INDEX
Property name of ICM's segment index.
static StringSEGMENT_INDEX_LENGTH
Property name of ICM's segment index length.
Constructor Summary
ICMGenerator()
Trivial 0-arguments constructor.
Method Summary
voidfillBlock()
voidsetup(Map attributes)

Field Detail

BLOCK_INDEX_LENGTH

public static final String BLOCK_INDEX_LENGTH
Property name of ICM's block index length.

CIPHER

public static final String CIPHER
Property name of underlying block cipher for this ICM generator.

OFFSET

public static final String OFFSET
Property name of ICM's offset.

SEGMENT_INDEX

public static final String SEGMENT_INDEX
Property name of ICM's segment index.

SEGMENT_INDEX_LENGTH

public static final String SEGMENT_INDEX_LENGTH
Property name of ICM's segment index length.

Constructor Detail

ICMGenerator

public ICMGenerator()
Trivial 0-arguments constructor.

Method Detail

fillBlock

public void fillBlock()

setup

public void setup(Map attributes)
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