cryptix.provider.key
Class IDEAKeyGenerator

java.lang.Object
  |
  +--xjava.security.KeyGenerator
        |
        +--cryptix.provider.key.RawKeyGenerator
              |
              +--cryptix.provider.key.IDEAKeyGenerator

All Implemented Interfaces:

java.lang.Cloneable, ExtendedKeyGenerator, Parameterized

public class IDEAKeyGenerator

extends RawKeyGenerator

A key generator for IDEA.

IDEA keys have a fixed length of 128 bits.

References:

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

$Revision: 1.1.1.1 $

Since:

Cryptix 2.2.0a, 2.2.2

Author:

David Hopwood

Constructor Summary

IDEAKeyGenerator()

Method Summary

boolean

isWeak(byte[] key) Returns true iff the byte array key represents a weak IDEA key.

Methods inherited from class cryptix.provider.key.RawKeyGenerator

engineGenerateKey, generateKey, generateKey, getDefaultKeyLength, getMaximumKeyLength, getMinimumKeyLength, initialize, initialize, isValidKeyLength, isWeakAllowed, setWeakAllowed

Methods inherited from class xjava.security.KeyGenerator

clone, engineGetParameter, engineSetParameter, getAlgorithm, getAlgorithms, getAlgorithms, getInstance, getInstance, getParameter, setParameter, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

IDEAKeyGenerator

public IDEAKeyGenerator()

Method Detail

isWeak

public boolean isWeak(byte[] key)

Returns true iff the byte array key represents a weak IDEA key.

IDEA has two non-overlapping classes of weak keys (bit numbering is from left to right, e.g. 0 denotes the most significant bit of the first byte):

• Keys with zeros in bit positions 0-25, 29-71, and 75-110 (inclusive) and any value in bits 26-28, 72-74, and 111-127. There are 2^23 weak keys in this class.

• Keys with zeros in bit positions 0-25, 41-71, 84-98, and 123-127 and any value in bit positions 26-40, 72-83, and 99-122. There are 2^51 weak keys in this class.

Overrides:

isWeak in class RawKeyGenerator

Parameters:

key - the byte array containing user key data.