 sequence to initialize OpenSSL random number generator. 
      On many platforms, including Linux and Windows, it may be leaved NIL (default), 
      because OpenSSL initializes the random number generator from OS specific service. But for 
      example on Solaris it may be necessary to supply this value. The minimum length required
      by OpenSSL is 128 bits. See here <a href="http://www.openssl.org/support/faq.html#USER1">
        http://www.openssl.org/support/faq.html#USER1</a> for the details.
    