Cryptographic software tools are two a penny on Linux, but complete encryption of a disk or partition is hardly worthwhile for individual small datasets. On the one hand, it takes a long time to complete the operation depending on the physical size of the storage medium; on the other hand, encrypted partitions are no longer portable. One remedy is cryptographic software that bundles the data into volumes of variable sizes. In this article, I look at TruPax 9, a simple but useful application for home use.

The standard solution – the undisputed King of the Hill, at least on Linux – was TrueCrypt until the developers surprisingly stopped working on the tool under partly unexplained circumstances in May 2014 [1]. As early as 2013, VeraCrypt was created as a fork of TrueCrypt [2]; it provides the same functionality while eliminating most known bugs from TrueCrypt.

Whereas VeraCrypt is designed for encrypting large datasets, TruPax [3] is a smaller tool and a good alternative for quickly and reliably keeping small amounts of data safe from unauthorized users. The volume format is compatible with VeraCrypt, so the volumes you create can be opened and edited in either application.

Setting up TruPax

Although the program has been in development for some time, you will so far not yet find TruPax in the software repositories of the popular distributions; this means picking up the program from the project page. Versions for 32-bit and 64-bit Linux are available along with the source code.

The source archive is a roughly 40MB ZIP file, which you can unpack and install in any directory. In the newly created subdirectory, call the ./install.sh script, which copies the complete program to /opt/trupax/ and adds a starter to the application menu. Because the installation script temporarily requires administrator privileges, it prompts you for a password. If you work in a distribution that only supports sudo after manually installing the appropriate software package, then you need to move the entire program folder to the /opt/ directory yourself.

After completing the setup, you can launch the GUI version of the program with the trupaxgui command. The trupax command-line tool, which also exists, accepts a large number of parameters, which it outputs when called without options. To use the software more conveniently in the future without changing to the command line, you can create a starter in the menu tree after the manual installation.

Interface

The application window (Figure 1) appears spartan at first glance: On the left is a large, empty list area immediately after launching the program. On the right are some buttons that let you create, edit, or unzip volumes and add some storage options. At the bottom left is a color-inverted activity and progress bar that indicates the current state of the software.

Figure 1: Spartan but yet very easy to use: the application window in TruPax 9.

At the top is a small horizontal menubar with File and Help entries. If you have any doubt about a feature, simply mouse over the item in question: The program provides bubble help that briefly explains the operation in a sentence or so.

Packing

The first step is to define which files or folders you want TruPax to add to the volume and encrypt. To do so, click Add Files or Add Folder at the top right in the program window. If you want TruPax to encrypt directories recursively (e.g., to add all the subfolders to the volume), check the Include Subfolders option.

If you want the software to save complete paths as in the source tree without saving the drive identifier, then also check the Save Full Path option. As soon as you click on the dialog to add files or folders, a file manager appears to let you select the desired content. The software displays the volume size and the size of the selected files in the status area at the bottom of the program window.

Finally, enter a name for the volume in the Label box. The name can comprise numbers and letters and up to 15 characters. Do not confuse this identifier with the actual name of the volume file: The identifier serves as a kind of drive identifier for the VeraCrypt volume.