Encrypting a common data partition between distros
Hi fellow linux users;
On my laptop (Dell Studio 1745) w/500GB HD, I have a common data partition shared by openSUSE. Fedora, FreeBSD, and windoze 7 currently. I would like to encrypt this partition (/Common) and have it accessible from all distros either with a passphrase key in /root or on a flash key. I've been researching on the web and there seem to be several possibilities using eCryptfs, Luks, cryptosetup, or any of several methods.
My question is, what have people here used and how well did it work? Also, what was required for setup (I'll probably have to explain/teach it to my wife who is technology challenged-but I still love her anyway) and my daughter who's just getting into linux.
I would like to be able to keep the entire directory on the hard drive but also have the ability to copy it to external USB device for transport.
Looking forward to some good responses and/or links to non-distro specific methods.