After many years of development and well-publicized budget overruns, the DoD’s Joint Tactical Radio System program (since reorganized and renamed) has recently given birth to a set of handheld voice and data radios — so-called Rifleman radios — built by a number of traditional military radio firms, including Exelis, GD, Harris, and Thales.

Here are some key differences between a Rifleman radio and a modern smartphone:

Because of their scale, smartphones outpace tactical radios in processing power by a significant margin and at significantly lower production cost. Yet tactical radios require custom radio hardware and software for military environments that would never be of interest to smartphone manufacturers. Rifleman and its associated waveforms were designed strictly for a military combat environment, where robust push-to-talk voice operation is by far the highest priority.

Figure 1. Mobile device tethered to tactical radio
Nevertheless, the advent of smartphones has driven military leadership to consider how best to utilize them. Powerful graphical environments have enabled a new generation of situational awareness applications, but the mobile devices’ relatively weak security and inability to communicate on resilient military networks prevent them from being used directly for tactical communications. Instead, smartphones must be tethered to rifleman radios, using the radio’s USB data port for sending maps and other data, but still relying on the radio itself for voice input, encryption, and link-layer transceiving (Figure 1).

At an order of magnitude higher in price than a smartphone, governments do not have the budget to enable all field personnel with tactical radios. Today, tactical radio possession ends at the platoon, or at best, squad leader, leaving other team members devoid of the valuable capability.

A next-generation mobile tactical communications solution would ideally meld the tactical radio and modern smartphone worlds, creating a solution that enables:

  • Powerful apps associated with modern mobile computing;
  • Ability to communicate on military tactical networks; and
  • Low cost, so every soldier can have one.

Figure 2. CSfC dual VPN approach
One might wonder why modern smartphone features cannot be simply added to the military radios, imbuing them with improved processing power, battery life, and graphical interfaces. This is not a feasible option because military radio development cycles are much longer than commercial smartphones, due to the need to follow tedious government contracting and certification processes. By the time a military radio actually ships in production quantities, commercial smartphones have evolved several cycles and are multiple generations ahead in hardware and software technology. Instead of trying to fit a square peg in a round hole, we consider a solution in which commercial smartphones are maximally leveraged with a cost and scope-reduced tactical radio.

Two important recent technology revolutions are making this vision possible: NSA CSfC cryptographic solutions and mobile security powered by separation kernel-based hypervisors.


Launched in 2012, the NSA’s Commercial Solutions for Classified (CSfC) program aims to leverage commercial off-the-shelf solutions to secure classified government networks and information. CSfC is a sharp change from the traditional approach of designing and building expensive government-purpose cryptographic communications equipment.

One of the key principles of CSfC is to implement multiple independent layers of commercial cryptographic products to replace a traditional, single-layer government cryptographic solution. For example, to send classified information over an open network (e.g. the Internet), the traditional government approach is to use a government-certified in-line encryptor, such as TACLANE or Talon. The encryptor contains specialized encryption hardware and software and undergoes a rigorous development and approval process (Type-1 NSA certification). Some Type-1 encryptors are orders of magnitude more expensive than commercial encryption products.