How can I do individual file encryption on Dropbox?

I have two methods in place with my Dropbox.

The first is using CryptKeeper . This creates and mounts enc_fs encrypted directories, independent of the Ubuntu implementation of Private.

Instructions by Scaine on using Cryptkeeper are here: How can I do individual file encryption on Dropbox?

The second is symlinking selected directories from ~/.Private into the Dropbox directory. This automatically uploads (and syncs) the encrypted versions of files normally situated in ~/Private. This assumes you have set up the encrypted Private directory! It can also be initially tricky to find the correct one to link.

While neither of these is strictly encryption of a single file, as both use a container of sorts, both methods scale easily as only changed files are uploaded.

As far as I know there will be an integrated encryption mechanism in Dropbox in the future. (I so in feature's requests). In the meantime you may encrypt/decrypt files locally then synchronise them via Dropbox storage.

Cryptkeeper allows for a per-file encryption folder to be set up as follows :

Install Cryptkeeper :

sudo apt-get install cryptkeeper

Create an encrypted container :

Left click on the Cryptkeeper icon, then right-click on your new container and delete it (Choose "Delete Encrypted Folder").

Choose "Ok" at the first prompt :

Then choose "No" at the last prompt :

Now you'll have a .Private_encfs folder in the directory you specified earlier. Copy this up to Dropbox at the location of your choosing, then simply import that folder from the Cryptkeeper icon. When you import, you'll be asked where you'd like your encrypted data to be mounted. Choose somewhere outside of Dropbox and you'll have a fully encrypted folder integrated into Nautilus into which you can place sensitive files and the encrypted versions of those files will be uploaded to Dropbox automatically.