cryptix.provider.elgamal

Class BaseElGamalPrivateKey

Implemented Interfaces:
ElGamalKey, ElGamalPrivateKey, PrivateKey, ElGamalPublicKey, PublicKey

public class BaseElGamalPrivateKey
extends BaseElGamalPublicKey
implements ElGamalPrivateKey

A class representing an ElGamal private key. This can also act as an ElGamal public key. It is called BaseElGamalPrivateKey to distinguish it from the interface ElGamalPrivateKey, without having to use fully-qualified names.

References:

  1. Bruce Schneier, "Section 19.6 ElGamal," Applied Cryptography, 2nd Edition, John Wiley & Sons, 1996.

  2. IEEE P1363 draft standard, http://stdsbbs.ieee.org/groups/1363/index.html

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

$Revision: 1.2 $

Author:
David Hopwood
Since:
Cryptix 2.2.2
See Also:
ElGamalKey, java.security.Cipher, java.security.Signature

Field Summary

protected BigInteger
x

Fields inherited from class cryptix.provider.elgamal.BaseElGamalPublicKey

g, p, y

Constructor Summary

BaseElGamalPrivateKey(BigInteger p, BigInteger g, BigInteger x)
Constructs a BaseElGamalPrivateKey with the specified prime p, base g, and private value x.
BaseElGamalPrivateKey(BigInteger p, BigInteger g, BigInteger x, BigInteger y)
Constructs a BaseElGamalPrivateKey with the specified prime p, base g, private value x, and pre-calculated public value y = gx mod p.
BaseElGamalPrivateKey(ElGamalParams params, BigInteger x)
Constructs a BaseElGamalPublicKey with a prime and base taken from an object implementing java.security.interfaces.ElGamalParams, and the specified private value x.

Method Summary

BigInteger
getX()
Returns the value of x (the private key).

Methods inherited from class cryptix.provider.elgamal.BaseElGamalPublicKey

getAlgorithm, getEncoded, getFormat, getG, getP, getY

Field Details

x

protected BigInteger x

Constructor Details

BaseElGamalPrivateKey

public BaseElGamalPrivateKey(BigInteger p,
                             BigInteger g,
                             BigInteger x)
Constructs a BaseElGamalPrivateKey with the specified prime p, base g, and private value x.

The public value y = gx mod p will be calculated.

Parameters:
p - the prime as a java.math.BigInteger
g - the base as a java.math.BigInteger
x - the value of x as a java.math.BigInteger

BaseElGamalPrivateKey

public BaseElGamalPrivateKey(BigInteger p,
                             BigInteger g,
                             BigInteger x,
                             BigInteger y)
Constructs a BaseElGamalPrivateKey with the specified prime p, base g, private value x, and pre-calculated public value y = gx mod p.
Parameters:
p - the prime as a java.math.BigInteger
g - the base as a java.math.BigInteger
x - the value of x as a java.math.BigInteger
y - the value of y as a java.math.BigInteger

BaseElGamalPrivateKey

protected BaseElGamalPrivateKey(ElGamalParams params,
                                BigInteger x)
Constructs a BaseElGamalPublicKey with a prime and base taken from an object implementing java.security.interfaces.ElGamalParams, and the specified private value x.

The public value y = gx mod p will be calculated.

Parameters:
params - the parameters for this key
x - the value of x as a java.math.BigInteger
See Also:
ElGamalParams

Method Details

getX

public BigInteger getX()
Returns the value of x (the private key).
Specified by:
getX in interface ElGamalPrivateKey
Returns:
x as a java.math.BigInteger