Password-protecting the folder won't really do a whole lot if they can just log in as an administrator and claim ownership of the directory themselves.
I'd suggest installing TrueCrypt, and using that to create a file-based encrypted volume. Then put your DropBox directory inside that, and only folks who know the decryption password can get to it.
Note that they could easily install a keylogger on your PC to learn your decryption password without your knowledge.
Also, the requisite disclaimer: Check with your IT department, and don't do anything contrary to established IT policy. Oftentimes organizations frown on personal use of work property (your PC) and resources (the bandwidth used to download from/upload to DropBox), so make sure you aren't violating any rules that could land you in trouble.
It's great to encrypt the folder but again, what stops the admin to reset your password and then go to Dropbox preferences, change the dropbox-sync-folder location and sync the whole lot in a non-encrypted folder? – Mehrad – 2017-11-06T01:31:06.033
I am the IT department ;) I work in a very small office with two other people. It doesn't need to be massive security, I just dislike the idea my boss could easily snoop through my personal files. – John Hunt – 2011-05-13T00:08:45.910
2Do you mean put the encrypted volume inside the Dropbox folder? – sblair – 2011-05-13T00:10:14.927
@sblair Nope, I mean the DropBox folder inside the encrypted volume. In this way you have to decrypt and mount the volume before any of the DropBox data is available. – Kromey – 2011-05-13T00:16:32.227
@Kromey Ok, but what if an "attacker" simply launched the Dropbox application? Dropbox would start syncing files to the local machine, completely bypassing the encryption container. I think it would be more secure to have a single file-based encrypted volume, containing all sensitive data, inside the Dropbox folder. – sblair – 2011-05-13T00:31:13.787
@sblair As I don't use Dropbox, I can't speak to the specifics of how it works, but I would be shocked (and appalled!) if there were no option to not remember a user's password to sync files -- i.e. you'd have to enter the password every time you launched the application. If Dropbox is incapable of doing this, I would have to conclude that it is inherently an unacceptable security risk. ...Just looked this up, and apparently Dropbox will remember your password automatically, with no option not to. Not cool, not safe, not secure. – Kromey – 2011-05-13T00:37:38.997
@Kromey In it's defence, there's no point asking for a password after booting/launching unless the files are already encrypted on the disk. – sblair – 2011-05-13T01:04:00.473
Still more secure than just having my files in c:\Documents\Dropbox or whatever.. I understand it's not great but I was just looking for a fairly easy way to keep the files hidden from plain view. You can actually log out of dropbox by clicking 'unlink this computer' – John Hunt – 2011-05-13T01:05:14.623
Plus I was keen on using truecrypt :) – John Hunt – 2011-05-13T01:05:49.633
Ok, so if dropbox can't find it's dropbox folder it doesn't log in and forgets your password - this means that as long as the truecrypt volume is mounted after dropbox starts it's quite secure. – John Hunt – 2011-05-16T22:32:23.673
@John Hunt Well, except for the fact that DropBox stores your username and password in a plaintext file that anyone could simply open and read at their leisure, independent of the application itself... – Kromey – 2011-05-16T22:57:10.087
@Kromey That problem has been addressed in version 1.2.
– sblair – 2011-05-17T19:57:34.417@sblair Unless that encrypted database is decrypted via the user supplying a password or key of some kind, it's little more than obfuscation of the database, and it's just a matter of time before someone decompiles Dropbox and figures out how to decrypt any arbitrary database. Sure, it'll keep out casual snoopers, but anyone who knows what they're doing won't be troubled by it (of course, those folks could easily just employ a keylogger anyway). – Kromey – 2011-05-17T20:39:31.927