EncFS is a piece of FOSS that lets you work with a filesystem interface to a created crypted folder. It is thus transparent to the user. For more information, see previous post.

I came over a special option today playing around with EncFS. When issuing the command $ encfs ~/crypted ~/interface , and the directory ~/interface was not empty, I got a warning from FUSE – letting me know that it was not empty. However, it also gave me a solution to the problem! Simply add the option nonempty to the mount command, everything is dandy.

$ encfs -o nonempty ~/crypted ~/interface

The files that already was present in the target ~/interface was no longer there – just the decrypted content from my ~/crypted filesystem. But, to my surprise, when I unmounted the encrypted filesystem, the original files that were in the mount point in the beginning, appeared again!

$ fusermount -u ~/interface

The files were not lost! They simply got hidden!

I see a great application in this feature. Let’s say you have a system with encrypted home folders for each user of the system. When a user login, their encrypted home folder is mounted, and their files are made available to them. They do not even have to know it is encrypted – what do they care!?

Now, let’s say somebody needs to get some information about a fellow student/colleague, i.e. contact information and such. Why not leave a file in their unencrypted, open home folder for everyone to see? The folder is already there – doing nothing – so why not put it to use!

Use case

Let’s say Fred wants to get Maya’s e-mail address. He simply goes to here home-folder and retrieves her contact information

# fred@computer $ cd /home/maya/
# fred@computer $ ls

A well – maybe this has been done before… I just found out 🙂

For other FUSE options

$ encfs -H