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<A NAME="SecureRandom()"><!-- --></A><H3>
SecureRandom</H3>
<PRE>
public <B>SecureRandom</B>()</PRE>
<DL>
<DD><p>By using this constructor, the caller obtains a SecureRandom object
 containing the implementation from the highest-priority installed
 provider that has a SecureRandom implementation.
 
 <p>Note that this instance of SecureRandom has not been seeded.
 A call to the <code>setSeed</code> method will seed the SecureRandom
 object.  If a call is not made to <code>setSeed</code>, the first call
 to the <code>nextBytes</code> method will force the SecureRandom object
 to seed itself.

 <p>This constructor is provided for backwards compatibility. 
 The caller is encouraged to use one of the alternative
 <code>getInstance</code> methods to obtain a SecureRandom object.</DL>
<HR>

<A NAME="SecureRandom(byte[])"><!-- --></A><H3>
SecureRandom</H3>
<PRE>
public <B>SecureRandom</B>(byte[]&nbsp;seed)</PRE>
<DL>
<DD><p>By using this constructor, the caller obtains a SecureRandom object
 containing the implementation from the highest-priority installed
 provider that has a SecureRandom implementation. This constructor 
 uses a user-provided seed in
 preference to the self-seeding algorithm referred to in the empty
 constructor description. It may be preferable to the empty constructor
 if the caller has access to high-quality random bytes from some physical
 device (for example, a radiation detector or a noisy diode).
 
 <p>This constructor is provided for backwards compatibility. 
 The caller is encouraged to use one of the alternative
 <code>getInstance</code> methods to obtain a SecureRandom object, and
 then to call the <code>setSeed</code> method to seed it.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>seed</CODE> - the seed.</DL>
</DD>
</DL>
<HR>

<A NAME="SecureRandom(java.security.SecureRandomSpi, java.security.Provider)"><!-- --></A><H3>
SecureRandom</H3>
<PRE>
protected <B>SecureRandom</B>(<A HREF="../../java/security/SecureRandomSpi.html">SecureRandomSpi</A>&nbsp;secureRandomSpi,
                       <A HREF="../../java/security/Provider.html">Provider</A>&nbsp;provider)</PRE>
<DL>
<DD>Creates a SecureRandom object.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>secureRandomSpi</CODE> - the SecureRandom implementation.<DD><CODE>provider</CODE> - the provider.</DL>
</DD>
</DL>

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<A NAME="getInstance(java.lang.String)"><!-- --></A><H3>
getInstance</H3>
<PRE>
public static <A HREF="../../java/security/SecureRandom.html">SecureRandom</A> <B>getInstance</B>(<A HREF="../../java/lang/String.html">String</A>&nbsp;algorithm)
                                throws <A HREF="../../java/security/NoSuchAlgorithmException.html">NoSuchAlgorithmException</A></PRE>
<DL>
<DD>Generates a SecureRandom object that implements the specified
 Pseudo Random Number Generator (PRNG) algorithm. If the default
 provider package provides an implementation of the requested PRNG,
 an instance of SecureRandom containing that implementation is returned.
 If the PRNG is not available in the default 
 package, other packages are searched.

 <p>Note that the returned instance of SecureRandom has not been seeded.
 A call to the <code>setSeed</code> method will seed the SecureRandom
 object.  If a call is not made to <code>setSeed</code>, the first call
 to the <code>nextBytes</code> method will force the SecureRandom object
 to seed itself.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>algorithm</CODE> - the name of the PRNG algorithm.
 See Appendix A in the <a href=
 "../../../guide/security/CryptoSpec.html#AppA">
 Java Cryptography Architecture API Specification &amp; Reference </a> 
 for information about standard PRNG algorithm names.<DT><B>Returns:</B><DD>the new SecureRandom object.<DT><B>Throws:</B><DD><CODE><A HREF="../../java/security/NoSuchAlgorithmException.html">NoSuchAlgorithmException</A></CODE> - if the PRNG algorithm is
 not available in the caller's environment.<DT><B>Since: </B><DD>1.2</DD>
</DL>
</DD>
</DL>
<HR>

<A NAME="getInstance(java.lang.String, java.lang.String)"><!-- --></A><H3>
getInstance</H3>
<PRE>
public static <A HREF="../../java/security/SecureRandom.html">SecureRandom</A> <B>getInstance</B>(<A HREF="../../java/lang/String.html">String</A>&nbsp;algorithm,
                                       <A HREF="../../java/lang/String.html">String</A>&nbsp;provider)
                                throws <A HREF="../../java/security/NoSuchAlgorithmException.html">NoSuchAlgorithmException</A>,
                                       <A HREF="../../java/security/NoSuchProviderException.html">NoSuchProviderException</A></PRE>
<DL>
<DD>Generates a SecureRandom object for the specified PRNG
 algorithm, as supplied from the specified provider, if such a
 PRNG implementation is available from the provider.

 <p>Note that the returned instance of SecureRandom has not been seeded.
 A call to the <code>setSeed</code> method will seed the SecureRandom
 object.  If a call is not made to <code>setSeed</code>, the first call
 to the <code>nextBytes</code> method will force the SecureRandom object
 to seed itself.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>algorithm</CODE> - the name of the PRNG algorithm.
 See Appendix A in the <a href=
 "../../../guide/security/CryptoSpec.html#AppA">
 Java Cryptography Architecture API Specification &amp; Reference </a> 
 for information about standard PRNG algorithm names.<DD><CODE>provider</CODE> - the name of the provider.<DT><B>Returns:</B><DD>the new SecureRandom object.<DT><B>Throws:</B><DD><CODE><A HREF="../../java/security/NoSuchAlgorithmException.html">NoSuchAlgorithmException</A></CODE> - if the requested PRNG
 implementation is not available from the provider.<DD><CODE><A HREF="../../java/security/NoSuchProviderException.html">NoSuchProviderException</A></CODE> - if the provider has not been
 configured.<DT><B>Since: </B><DD>1.2</DD>
<DT><B>See Also: </B><DD><A HREF="../../java/security/Provider.html"><CODE>Provider</CODE></A></DL>
</DD>
</DL>
<HR>

<A NAME="getProvider()"><!-- --></A><H3>
getProvider</H3>
<PRE>
public final <A HREF="../../java/security/Provider.html">Provider</A> <B>getProvider</B>()</PRE>
<DL>
<DD>Returns the provider of this SecureRandom object.<DD><DL>
<DT><B>Returns:</B><DD>the provider of this SecureRandom object.</DL>
</DD>
</DL>
<HR>

<A NAME="setSeed(byte[])"><!-- --></A><H3>
setSeed</H3>
<PRE>
public void <B>setSeed</B>(byte[]&nbsp;seed)</PRE>
<DL>
<DD>Reseeds this random object. The given seed supplements, rather than
 replaces, the existing seed. Thus, repeated calls are guaranteed
 never to reduce randomness.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>seed</CODE> - the seed.</DL>
</DD>
</DL>
<HR>

<A NAME="setSeed(long)"><!-- --></A><H3>
setSeed</H3>
<PRE>
public void <B>setSeed</B>(long&nbsp;seed)</PRE>
<DL>
<DD>Reseeds this random object, using the eight bytes contained 
 in the given <code>long seed</code>. The given seed supplements, 
 rather than replaces, the existing seed. Thus, repeated calls 
 are guaranteed never to reduce randomness. 
 
 <p>This method is defined for compatibility with 
 <code>java.util.Random</code>.<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../java/util/Random.html#setSeed(long)">setSeed</A></CODE> in class <CODE><A HREF="../../java/util/Random.html">Random</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>seed</CODE> - the seed.</DL>
</DD>
</DL>
<HR>

<A NAME="nextBytes(byte[])"><!-- --></A><H3>
nextBytes</H3>
<PRE>
public void <B>nextBytes</B>(byte[]&nbsp;bytes)</PRE>
<DL>
<DD>Generates a user-specified number of random bytes.  This method is
 used as the basis of all random entities returned by this class
 (except seed bytes).<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../java/util/Random.html#nextBytes(byte[])">nextBytes</A></CODE> in class <CODE><A HREF="../../java/util/Random.html">Random</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>bytes</CODE> - the array to be filled in with random bytes.</DL>
</DD>
</DL>
<HR>

<A NAME="next(int)"><!-- --></A><H3>
next</H3>
<PRE>
protected final int <B>next</B>(int&nbsp;numBits)</PRE>
<DL>
<DD>Generates an integer containing the user-specified number of
 pseudo-random bits (right justified, with leading zeros).  This
 method overrides a <code>java.util.Random</code> method, and serves
 to provide a source of random bits to all of the methods inherited
 from that class (for example, <code>nextInt</code>,
 <code>nextLong</code>, and <code>nextFloat</code>).<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../java/util/Random.html#next(int)">next</A></CODE> in class <CODE><A HREF="../../java/util/Random.html">Random</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>numBits</CODE> - number of pseudo-random bits to be generated, where
 0 <= <code>numBits</code> <= 32.<DT><B>Returns:</B><DD>an <code>int</code> containing the user-specified number
 of pseudo-random bits (right justified, with leading zeros).</DL>
</DD>
</DL>
<HR>

<A NAME="getSeed(int)"><!-- --></A><H3>
getSeed</H3>
<PRE>
public static byte[] <B>getSeed</B>(int&nbsp;numBytes)</PRE>
<DL>
<DD>Returns the given number of seed bytes, computed using the seed
 generation algorithm that this class uses to seed itself.  This
 call may be used to seed other random number generators.

 <p>This method is only included for backwards compatibility. 
 The caller is encouraged to use one of the alternative
 <code>getInstance</code> methods to obtain a SecureRandom object, and
 then call the <code>generateSeed</code> method to obtain seed bytes
 from that object.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>numBytes</CODE> - the number of seed bytes to generate.<DT><B>Returns:</B><DD>the seed bytes.</DL>
</DD>
</DL>
<HR>

<A NAME="generateSeed(int)"><!-- --></A><H3>
generateSeed</H3>
<PRE>
public byte[] <B>generateSeed</B>(int&nbsp;numBytes)</PRE>
<DL>
<DD>Returns the given number of seed bytes, computed using the seed
 generation algorithm that this class uses to seed itself.  This
 call may be used to seed other random number generators.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>numBytes</CODE> - the number of seed bytes to generate.<DT><B>Returns:</B><DD>the seed bytes.</DL>
</DD>
</DL>
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