Command System Protection for Commercial Communication Satellites

Advances in computer and communication technology have led to a growing concern on the part of commercial communication satellite operators over the vulnerability of their high valued assets in space. An antagonist with a modicum of satellite command system knowledge and modest financial means, could disrupt operations, or, in the worst case, jeopardize the health and safety of orbiting satellites by commanding the satellites into undesirable configurations. Consequently, a critical need has emerged to protect the satellite command systems from malicious or inadvertent interference. Government too, recognizing the need to protect all US space systems, has recently promulgated a policy through the National Telecommunications and Information Systems Security Committee (NTISSC) that declares that future Government use of commercial satellites shall be limited to those using "accepted techniques necessary to protect the command/control uplink." The Government policy together with the threat posed by technically astute adversaries has given a strong impetus to commercial satellite operators to protect command systems of their satellites. American Satellite Company (ASC), a leader in providing communications services to Government and businesses, has taken a lead in incorporating a command link protection system on its satellites. The system uses the National Bureau of Standards (NBS) Data Encryption Standard (DES) algorithm to deny access to the satellite command system to anyone but an authorized ASC ground control station. The system uses the same technology as the other command system elements, and is transparent to the satellite users.