I have found this post via Mubix . This a recurrent subject and I have seen many posts in the past.
Since there is a total lack of security in Dropbox, many people have thought it would be a good idea to encrypt its content, so only the legit owner can access the data. The problem comes when many solutions encrypt complete volumes, forcing us to sync the complete volume to dropbox over and over again, which is not handy at all.
The advantage of EncFS is that it encrypts per file, making it really convenient for our purpose.