If you are running Red Hat Linux and want the Cryptographic File System (also available for most BSD-derived Unix systems and most current Linux releases), go to http://www.replay.com/redhat/cfs.html If you are running Linux 2.0.X and want the Transparent Cryptographic File System (improves on Matt Blaze's CFS, they say), go to http://vales.uni.net/tcfs/ - d.