App that encrypts and uploads folder to Dropbox?

[PlayMobile]

I can not find any app that can do this:

* Encrypts files before sending them to Dropbox.
* You can select entire directories and new files are uploaded automatically.
* The files can be decrypted with a computer (Windows software).
* Uploads automatically when connected via WIFI.

All apps I've tried got the problem that you have to select individual files, this does not work for me.

Anyone know an app that can do what I want?

 

[PlayMobile]

If it can upload to a FTP-server it would also work aslong as the files are encrypted and can get decrypted on my Windows-PC.