Short Message Service (sms) security solution for mobile devices

2. 
SMS for Military Applications 
Military organizations are particularly concerned with the confidentiality, 
integrity and availability of information in conventional military operations. Given 
the GSM and SMS vulnerabilities described in the previous Sections, none of the 
current security properties is sufficient for military high assurance applications. 
However, the emergence of asymmetric threats and the increased participation 
of the military in Humanitarian Aid Disaster Relief (HADR) operations have 
resulted in the need for the military to work closely with civilian institutions or 
Non-Government Organizations, such as Red Cross. Military communications 
devices and networks may not be suitable for civil-military communications 
because of Operational Security (Opsec) limitations. Furthermore, the civilians 
are not trained to operate the military communications devices. GSM and SMS 
may be able to fill this void in the civil-military communications network. 
The military has recognized the pervasiveness of the GSM network and 
the need to leverage successful mature Commercial-Off-The-Shelf (COTS) 
technologies, such as GSM. Secure phones that are Type I certified have been 
developed and are in use in the military today [27]. However, the use of these 
phones is limited to voice traffic or modem connections, and the distribution of 
phones is limited due to cost and key management concerns. The rest of this 
Section discusses some current concerns of the military on the use of SMS and 
potential SMS applications that may be useful for the military, if the security of 
SMS messages can be assured. 

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a. 
Current Concerns about SMS Usage 
The key concerns in the military are the confidentiality and integrity 
of SMS messages. It is often perceived that all military information must be 
protected with the highest level of assurance. However, security must be viewed 
in the context of the mission and the value of the information that needs to be 
protected. Not all information needs to be protected to the same level as national 
secrets. Overprotecting the data results in a waste of resources and places 
unnecessary constraints on the system. Besides the value of the content, the 
volatility of information is also very important when considering the security 
solution. A classic example is information on D-Day; the value of information is 
extremely high before D-Day. After D-Day, the information no longer needs to be 
protected. Tactical information on troop location is another example. The exact 
geographical position only needs to be protected from the enemy for the duration 
of the operation, assuming the operation is not a clandestine one. Therefore the 
issue of confidentiality and integrity protection must be viewed in the context of 
the value and volatility of information. 
Another area of concern is availability of service. GSM frequency is 
well known and electronic jamming is trivial. However, the same concern applies 
to GPS. GPS are known to be vulnerable and commercial GPS jammers are 
readily available. However, the military continues to rely on GPS for its 
operations. The key is to ensure that GPS jammers can be located and 
destroyed. The same can be applied to GSM. Just as GSM jammers can be 
bought, GPS jamming locators are also commercially available. They are 
typically used by GSM service providers to locate radio interference sources and 
to maintain a certain level of Quality of Service. The effective and creative use of 
such devices is the key in maintaining superiority in the frequency spectrum. 
With vendors constantly marketing high bandwidth devices, the 
bandwidth provided by SMS is perceived as insufficient for dynamic, fast moving, 
military applications. Again, the bandwidth usage must be viewed in context of 
the operation. A SMS message can be delivered end-to-end in seconds. A SMS 

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message is sufficient to encode the position, course, speed and status of a 
soldier or unit. Not every soldier is required to stream video. Therefore, SMS can 
still fulfill the needs of some applications.
The physical loss of mobile devices is a concern for all mobile 
communications equipment. What happens if the soldier is captured? What if 
device falls into the hands of the enemy? Can the enemy masquerade as an 
insider of the network and foil the operation? These are questions that constantly 
arise during the development of any military mobile communication system or 
device. The same questions apply of GSM handsets.
The following Sections highlight the advantages of SMS over 
conventional military communications devices and specific scenarios where the 
SMS may be useful for military applications.