a tag search would help you
here it is
http://daemonforums.org/showthread.php?t=2209
advantage: you can't access data unless you have keys/paraphrase
if you don't use encryption almost every file (depends on how willing someone will be to recover) you ever have deleted, can be restored....
http://www.usenix.org/publications/l...apers/gutmann/
encryption also can be beaked, but at least it's not that simple