> you can use something innocent looking which you just have laying around on the machine, like a picture. This works well on a file you decrypt often. What ca

> you can use something innocent looking which you just have laying around on the machine, like a picture. This works well on a file you decrypt often. What can happen with infrequently used files is that many years pass, you upgrade computers and/or operating systems, remember to copy your encrypted volumes. When you try to decrypt your volume, you remember the passcode, but forget which "innocuous" file you used as a keyfile, even after you boot up your old computer you had handed down to your cousin.