Put your filesystem on a DRBD device?

You'll get a consistent clone every time you leave your laptop connected to your home network long enough for it to sync the changed blocks

Howdy,

here's what I did when I implemented the same kind of service:

first, I choose PGP (GPG) to encrypt the user's CC information in a database on a safe Linux system (firewalled and using an IDS).

here's my logic: information can be encrypted anytime using the public key, but the private key must be used for decryption. The public key is then stored on the server, but not the private one.

In case of stealing, you're safe so far.

Only one program access the CC information and need the private key. On startup, it asks for two information: the "real" private key and a "passphrase" of a minimum length. the key is then XORED with the passphrase and the result is hidden in memory. The passphrase is then given to the employees and changed daily (or anytime you wish).

So the CC info can be read if:
1- the server process was started by a thrusted admin knowing the private key, and
2- the person accessing the data know the day's passphrase.

if the passphrase is protected while being sent to the server and the employees are either "thrusted" or "unable to hack a secured unix system and debug the memory to restore an xored key", the system should be safe enough

backups can be made (the key's nowhere nead the hard disks) and the information given to the employees, the passphrase, can't be reused after the end of the day.

and if it's not secure enough for our most paranoid contenders, it's fun to realise anyway :)