Light Gap Data Transfer Tools

Want to Transfer Files Without Connecting to Another Device? Just Use the Light-Gapped Data Transfer Tool!

In a liberty-challenged part of the world, how can one transfer files for local distribution? Connecting to a mobile (or any other) device by cabling or drivers? They might be controlled by others (the freedom-oppressing government, foreign spies, your jealous and tech savvy girlfriend etc.). Transferring files wirelessly using some Wi-Fi or Bluetooth connection? These might also be controlled, intercepted, or even tapped (to record everything one does) all without your knowledge. In many liberty impoverished areas, Wi-Fi and cables are not readily or reliably available, making the task of transferring data a hassle. For example, someone that wants to move files from a home or office setting to somewhere that does not have the required infrastructure for cabling, Wi-Fi, or other simple direct connection would find the task very frustrating, if not impossible. In addition to providing connectionless data transfer, the ability to transfer data without cables, drivers, or a wireless connection would help prevent data exposure and identification by malicious third parties. Such an ability would be generally useful in any part of the world, but especially so in parts of the world with oppressive governments. How could this be accomplished?

A team of students at the University of Maryland - College Park (UMCP) have created a light-gapped approach, called the Light-Gapped Data Transfer Tool (LGDTT), to solve this problem. Consisting of students from the university's school of Computer Science and Engineering, the team seeks to develop open source Web and Android applications that will transfer data through a series of displayed QR codes rather than by network connection or physical connection.

LGDTT consists of two applications: a Web application and an Android application. The Web application is used as a sending module in order to transfer files to other devices. It works by displaying a series of quickly changing QR codes, each of which hold encoded data from the file being transferred. The user attaches a file to the Web application, which is encoded and then displayed on the screen as one or more QR codes; this application also includes various buttons and a text field for manipulating the application (i.e. finding missed QR codes, pausing the display of QR codes, cancelling the transfer, etc) as well as links to a help page and a page to download the Android application.

The Android application (see Figure 2 below) operates as both a receiving module in order to retrieve the transferred files and a sending module. It transfers files in the same way described in the Web application (see paragraph above); and it receives files by using the camera on the user's Android phone to scan the QR codes displayed by the Web application or by another Android smartphone that has this application installed. The scanned data is decoded, combined into a file, and saved in a folder named lightgap in the smartphone's Downloads folder.

The LGDTT team is composed of students from Professor Jim Purtilo's Software Engineering course of the Spring 2015 semester at the University of Maryland - College Park (UMCP). The team includes Daniel Dutil, Erik Koebke, Ben Summers, Nathan Twombly, Adeseye Afe, Ugo Madagu, and Patrick Owen.