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<TITLE>Getting the Digital Signature Algorithm (DSA) Parameters of a Key Pair (Java Developers Almanac Example)
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    <A HREF="../java.security/pkg.html">java.security</A><font color="#666666" class="xsmall-font">
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        <B><A HREF="../java.security/pkg.html#Public and Private Keys">Public and Private Keys</A></B><font color="#666666" class="xsmall-font">
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  <h3>e200. Getting the Digital Signature Algorithm (DSA) Parameters of a Key Pair</h3>

The DSA requires three parameters to create a key pair --- the
prime (P), the subprime (Q), and the base (G).  These three values are
used to create a private key (called X) and a public key (called Y).

<P> This example creates a DSA key pair with provider-supplied
default values for P, Q, and G, and then retrieves the default values.


<pre>    try {
        // Generate a 1024-bit Digital Signature Algorithm (DSA) key pair
        KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
        keyGen.initialize(1024);
        KeyPair keypair = keyGen.genKeyPair();
        DSAPrivateKey privateKey = (DSAPrivateKey)keypair.getPrivate();
        DSAPublicKey publicKey = (DSAPublicKey)keypair.getPublic();
    
        // Get p, q, g; they are the same for both private and public keys
        DSAParams dsaParams = privateKey.getParams();
        BigInteger p = dsaParams.getP();
        BigInteger q = dsaParams.getQ();
        BigInteger g = dsaParams.getG();
    
        // Get the private key's X
        BigInteger x = privateKey.getX();
    
        // Get the public key's Y
        BigInteger y = publicKey.getY();
    } catch (NoSuchAlgorithmException e) {
    }
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            &nbsp;<b>Related Examples</b></font></td>
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e197. <a class="eglink" href="ListKeyPairGen.html?l=rel">
    Listing All Available Public/Private Key Generators
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e198. <a class="eglink" href="GenKeyPair.html?l=rel">
    Generating a Public/Private Key Pair
</a>
<br>

e199. <a class="eglink" href="GetKeyPairBytes.html?l=rel">
    Getting the Bytes of a Generated Key Pair
</a>
<br>

e201. <a class="eglink" href="CreateDsa.html?l=rel">
    Creating Key Objects from a Set of Digital Signature Algorithm (DSA) Parameters
</a>
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        See also: 
<a class="eglink" href="/egs/java.security/pkg.html?l=rel#Key%20Store">
    Key Store
</a>&nbsp;&nbsp;

<a class="eglink" href="/egs/java.security/pkg.html?l=rel#Message%20Digests">
    Message Digests
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<a class="eglink" href="/egs/java.security/pkg.html?l=rel#Permissions">
    Permissions
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<a class="eglink" href="/egs/java.security/pkg.html?l=rel#Policy%20Files">
    Policy Files
</a>&nbsp;&nbsp;

<a class="eglink" href="/egs/java.security/pkg.html?l=rel#Signatures">
    Signatures
</a>&nbsp;&nbsp;

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