title: PBEKeySpec what do the iterationCount and keyLength parameters influence?
body: <p>Delving into the java encryption and hashing world I see examples of the constructor for the <code>PBEKeySpec</code> class with various values for the <code>iterationCount</code> and the <code>keyLength</code> parameters. Nothing seems to explain what these parameters impact or mean.</p>
  
  <p>I am assuming that <code>keyLength</code> is how long the key is so 32 bit encryption would take a value of 32 for the key length, but that assumption feels wrong. My guess for the <code>iterationCount</code> is the number of times each char is encrypted, again not feeling the love on that assumption either.</p>
  
  <p>Links to info or an explanation are appreciated.</p>