I would highly recommend taking a look at how Oracle is handling
encryption in the database in 10.2 (or whatever they're calling it).
They've done a good job of thinking out how to handle things like
managing the keys.
I know that Oracle magazine did an article on it recently; you should be
able to find that online somewhere.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461