<A target="_blank" href="http://www.wissel.net/blog/d6plinks/SHWL-8NAJVV?Open&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Wisselnet+%28wissel.net%29">Stephan Wissel lists several methods of protecting data and the problems each presents</A>. Then he provides some code to help implement one of the methods.