User friendly security solutions for the MUSO common air interface (CAI)

The Navy Communications Satellite Program Office is directing the development of the Mobile User Objective Svstem (MUOS) to meet a continuing Department of Defense (DoD) requirement for mobile unprotected narrowband beyond line-of-sight communications. The MUOS will replace the current UHF Follow-On (UFO) satellite constellation as those satellites reach end-of-life, and needs to provide a higher quality of service than the current UFO system is capable of providing. As part of this effort a new Common Air Interface (CAI) will be developed to standardize the waveform used between MUOS user terminals and the satellite. This paper describes the security issues that will need to be considered when specifying this CAI. The CAI needs to provide user-friendly security solutions for the protection of both orderwire and baseband information, with the goal of eliminating the requirement for users to handle keying material.