DropBox with TrueCrypt on Lion and Windows

After receiving my new MacBook, I wanted to sync a whole set of files between both systems. For convenience, I decided to use DropBox instead of a thumb drive and for security reasons, I decided to use TrueCrypt to encrypt some of my confidential data within the DropBox folders.

Using a TrueCrypt container within DropBox is quite convenient as I am syncing my DropBox folders with various machines (e.g. at work). However, I do not want to access these file there nor do I want that an admin might check out my “oooh so secret” files (not saying they would, though).

DroppBox with TrueCrypt on Lion and Windows

With my rusty Mac OS kung-fu, I had to install TrueCrypt first. Of course, this failed and being the first app I did install on Lion, this was somewhat demotivating. Before you have install a version from MACFuse. It seems that the official version is not up to date, however, there are rumors you might use the latest version provided at Tuxera.com.

Once MACFuse and TrueCrypt are set up and the machine is rebooted, create a TrueCrypt container within DropBox. When creating on OS X Lion, you might want choose FAT for the containers file system so you can mount it on the Windows system as well. However, any change within this container will synchronize the container as a whole. Not being very efficient if this is a 256 MB file, it seems that one can turn of the timestamp of the TrueCrypt container to avoid syncing it. This will prevent that the container gets synced after files within the container are changes, however, the itself files are still updated. To turn it of, open TrueCrypt and select Settings / Preferences… chose the Security tab and uncheck the Preserve modifications timestamp of file container checkbox.

TrueCrypt Settings on OS X Lion

Of course, the same has to be done on your Windows system.

TrueCrypt Settings on Windows 7

Once both settings are applied, only the initial sync of the container will take some time. Thereafter, only the files within the container are updated. for me this seems to be a quite good solution to keep my boxes in sync and to avoid rubbernecks seeking through my private stuff. The setup is done quite easily, only the hassle with MACFuse was quite annoying.

Leave a Reply