Welcome

This software enables you to transparently encrypt your Dropbox folder on your PC. It also supports sharing files with other Dropbox users, while still encrypting the shared data.

Warning: This is just proof-of-concept code and should NOT be used in production environments

The associated master's thesis can be found here: http://sar.informatik.hu-berlin.de/research/publications/SAR-PR-2016-01/SAR-PR-2016-01_.pdf

Tested platforms:

• Debian Jessie (32 Bit)

Building

To build the software, execute the following commands:

git clone https://github.com/eriknellessen/encrypting-cloud-storages
cd encrypting-cloud-storages/build
cmake ..
make install

Using

Transparent client-side encryption

Setting up Dropbox

This needs to be done only once. It must be done before starting the transparent client-side encryption or Dropbox.

1. Create user Dropbox: adduser Dropbox
2. Install Dropbox (download *.deb from here)
3. Start Dropbox as normal user, so the files are installed. When it asks for your e-mail, close dropbox.
4. Grant user Dropbox write access to your home directory, e.g. by executing chmod 777 ~
5. Execute xhost + (as normal user)
6. Start Dropbox (as user Dropbox)
7. Choose your home directory when asked where to place the Dropbox directory
8. Terminate Dropbox
9. Reclaim your Dropbox directory via chown
10. Remove all files in Dropbox, e.g. by executing rm -rf ./* ./.* inside the Dropbox directory

Starting the transparent client-side encryption

This needs to be done before starting Dropbox.

To start the transparent client-side encryption, execute the following command:

bin/start_fuseecs.sh

Starting Dropbox

This must not be done before starting the transparent client-side encryption.

We need to share our display, so the user Dropbox can use it. We then switch to the user Dropbox and start the program:

xhost +
su Dropbox
/home/user/.dropbox-dist/dropbox-lnx.$PLATFORM-$VERSION/dropbox

Sharing files

For sharing a folder, execute the following command:

bin/start_share_a_folder.sh $FOLDER $OPENPGP_FINGERPRINT

For example, the command could look like this:

bin/start_share_a_folder.sh /home/user/Dropbox/folder_to_share A6506F46

This shares the folder in a cryptographic way. Afterwards, you still have to share the folder via Dropbox.