DHParameterGenerator (Oracle Fusion Middleware Crypto Java API Reference)

Normally, Diffie-Hellmain parameters are distributed (and generated) by a central agency agreed upon by participating parties, so a DHParameterGenerator will be invoked far less often than, say, a generator for RSA, DSA (or DH) keypairs.

Parameter generation is also similarly resource intensive: for example, generation of the sample parameters given in Annex D of X9.42 takes about 100 seconds on a Pentium-based JVM.

See Also:: DHParams

Constructor Summary
`DHParameterGenerator()` Constructs a new, uninitialized `DHParameterGenerator` instance.

Method Summary
`DHParams`	`generateParameters()` Generates Diffie-Hellman parameters using the algorithms specified in Annex B, X9.42.
`java.lang.String`	`getAlgorithm()` Returns "Diffie-Hellman".
`void`	`initialize(int L, int m)` Initialize this `DHParameterGenerator` with the given bit lengths for p and q, and the default `RandomBitsSource`.
`void`	`initialize(int L, int m, RandomBitsSource rbs)` Initialize this `DHParameterGenerator` of the given bit lengths and `RandomBitsSource`.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

DHParameterGenerator

public DHParameterGenerator()

Constructs a new, uninitialized DHParameterGenerator instance.

Method Detail

initialize

public void initialize(int L,
                       int m)

Initialize this DHParameterGenerator with the given bit lengths for p and q, and the default RandomBitsSource.

Parameters:: L - the bit length of p; L=256n, n>=4; m - the bit length of q; m>=160

initialize

public void initialize(int L,
                       int m,
                       RandomBitsSource rbs)

Initialize this DHParameterGenerator of the given bit lengths and RandomBitsSource.

Parameters:: L - the bit length of p; L=256n, n>=4; m - the bit length of q; m>=160; rbs - the random bit source used to generate the parameters

getAlgorithm

public java.lang.String getAlgorithm()

Returns "Diffie-Hellman".

generateParameters

public DHParams generateParameters()

Generates Diffie-Hellman parameters using the algorithms specified in Annex B, X9.42. The generator instance should be initialized before this method is invoked (otherwise an exception is thrown.)