[digitallyfree]

There has to be a point where the data is secured by a password, and you will need to keep that password safe both in your head and in a secure location. In your case this would be your password to your backup file.

Pick a good password for the backup and recall it every morning and at random points in the day; the intent is to make you remember it even under stress. Also have it printed out or written somewhere in a place that no one will notice/find - say as a scribbling in your sketchbook or printed at the bottom of a document in your file folder. If you're creative you can even hide it on a sticker inside an object or so forth. No one will know that the string there actually is your password, and if you want you can split it among different pages/etc.